# Precision Optic lens AKA aspherical for incandescent flash lights?



## jimjones3630 (Nov 8, 2007)

Have received several inquires regarding the use of precision optic lens in flash lights. Well, opened this thread first for modders who have used them to share their expectations, experience, set backs, opinions.

The asphere's more complex surface profile can eliminate spherical aberration and reduce other optical aberrations compared to a simple lens. A single aspheric lens can often replace a much more complex multi-lens system. The resulting device is smaller and lighter, and possibly cheaper than the multi-lens design.

LED modders have used aspherical lens and familiar with the critical distance set up of lens to LED and curvature of lens relationship. Often have head asphericals are for LEDs, they don't work with incandescents. Radical asphericals like fish eye types project the image of a incan. filiment and look fairly sick.

Hook's law helps classify glass types by sorting according to Young's moduli. BK7 is 82. This relates to amount of heat stress capability or specific thermal tension exist when a heat gradiant exist causing internal stress.

So much for the technical, perhaps someone with an understanding of glass properties will contribute.

This lens I found has more heat resistance than current usage borofloat or UCL windows an advantage with 100+ watt mods. Also, it focuses visible light into a culminated stream in a way I have not seen before. See pic below. The beam is a perfect circle, has more throw than with boro or UCL lens, and has usable side spill. 



 2/22/08 See post #29 for ongoing evaluations of lens and recommendations in post #29. jim


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## AlexGT (Nov 8, 2007)

*Re: Precision Optic lens for flash lights?*

Interesting, what are you using, and can it be used to focus a ROP?

AlexGT


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## greenlight (Nov 9, 2007)

*Re: Precision Optic lens for flash lights?*

Well, I'd like to know more. I've seen a lot of mag mods with aspherical lenses, but I wonder why they are more spherical than lenticular.


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## jimjones3630 (Nov 9, 2007)

*Re: Precision Optic lens for flash lights?*



AlexGT said:


> Interesting, what are you using, and can it be used to focus a ROP?
> 
> AlexGT[/quot
> 
> ...


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## jimjones3630 (Nov 9, 2007)

*Re: Precision Optic lens for flash lights?*

_lenticular_ is a term for the lens effect that creates a convex perspective of multiple images or light sources. That fits the fisheye looking aspherical lens I have seen used with LED mods.

Can you tell me the difference?



greenlight said:


> Well, I'd like to know more. I've seen a lot of mag mods with aspherical lenses, but I wonder why they are more spherical than lenticular.


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## LuxLuthor (Nov 9, 2007)

*Re: Precision Optic lens for flash lights?*

Jim, thanks very much for starting this thread. I had sent you a PM with this link, and some in the 50.8mm size had some measurements that were close to what you posted in your sales thread...but I'm not understanding all of their chart measurements as compared to the top line drawing.

Edit: After some more reading, I now see the diagram in this link has the following correlation. 

EFL - Effective Focal Length column = diagram letter "f" 
BFL - Back Focal Length = diagram letter "fb"
te - Edge Thickness
tc - Center Thickness

*Can you give the Surplus Shed part number of the one you found best of the four*? Thanks!

Edit: So now I'm guessing this one in your sales thread, because I'm not seeing any with a 3.8" edge thickness as you listed. What is hard to figure out is this one has a 254mm focal length, which is 10 inches, and must result in the lamp being way forward of the focal length origin. The closest to that on my first link to BrightenOptics is their lens #[FONT=Verdana, Arial, Helvetica, sans-serif]BOPX-S50.8-250. It's just hard to figure out using the focal length in an incand bulb....and basically because I don't know squat about how to identify lenses. Maybe I'll call these guys.
[/FONT]


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## jimjones3630 (Nov 9, 2007)

*Re: Precision Optic lens for flash lights?*

Lux, as in my reply to your pm the last link in your post here is the lens I used. I doubt it is the only one that could work.

Lux in your post here your trying to figure this out from a scientific point of view. I did not know squat about aspherical lens until read some of the threads in LED section.

What I understood is there is a relationship between curvature of the lens and distance between lens and bulb. 

Therefore, since that lens worked best with LEDS, as oppossed to one a few mm different reason leads to the conclusion with an incan. bulb given the correct wavelength it would be stunning.

Bought several blindly so to speak having only a theory based on logic instead of facts based on physics. 

Motivated out of need for lens, reflectors, switchs which can withstand the extreme heat of current mods one might say alot of things but I'm sticking with logic as why this particular lens works.

jim 




LuxLuthor said:


> Jim, thanks very much for starting this thread. I had sent you a PM with this link, and some in the 50.8mm size had some measurements that were close to what you posted in your sales thread...but I'm not understanding all of their chart measurements as compared to the top line drawing.
> 
> Edit: After some more reading, I now see the diagram in this link has the following correlation.
> 
> ...


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## jimjones3630 (Nov 9, 2007)

*Re: Precision Optic lens for flash lights?*

can someone tell me where moved to?

Thanks,jim


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## DM51 (Nov 10, 2007)

*Re: Precision Optic lens for flash lights?*

There was a previous thread where someone actually used an aspheric lens with an incan, but I can't find it. In the same way as with the LED pattern, there was a clear projection of the actual shape of the filament. 

An aspheric lens is designed to work best with a point source of light. The principle is similar to using an accurate reflector – it will work best with small sources of light, which is why the best-throwing pencil-beam lights are those with short-arc bulbs (for example, the Maxa Beam).

Because of the critical importance of focus, it would be necessary to use an incan bulb with as small a filament as possible, and more importantly a horizontal filament rather than a vertical one. The more powerful hotwires, with longer/vertical filaments, would not be suitable. 

Just looking at the WA 1111 & 1185, these are both fairly small and horizontal and would probably work OK. The 5761 is small-ish and horizontal, but the coil of the filament is larger, ~1.5 mm in diameter, and focus needs to be very accurate with an aspheric – 1.5 mm might sound small, but with this application it might be too large.

With an incan, you would get an enlarged and fairly precise projection of the filament’s shape, which would look quite weird and because of the artifacts it would have a pretty limited use, apart from wowing people who saw it.

LEDs are also very much more directional than incans. Even the widest-angle LED doesn’t emit light behind it, so it will throw at least 2x as much of its output forward compared to an incan bulb, where the beam is pretty well omni-directional (spherical) until directed by a reflector.

A reflector is in fact useless when used with an aspherical lens, as the lens only works with a point source. Any light hitting the lens via a reflector will still come out, but this will be in a random direction as spill. 

Depending on the diameter of the lens and its distance from the light source (a factor of its focal length) the useful focused light from an incan might be as little as ~15% of its output, while with a LED which threw most of its light forward in a fairly tight cone anyway, like a Cree XR-E, the figure might be even better than the ~66% you get with a reflector. 

I think for these reasons, LEDs will have a significant edge over incans with aspheric lenses.


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## jimjones3630 (Nov 10, 2007)

*Re: Precision Optic lens for flash lights?*

David,

Of course you points are true when using that size\curature of aspherical LED moders use.

Some people who use that type of aspherical I've read over and over in different threads their conclusion is as yours aspherical are better suited for LEDS and not incan. 

The current wisdom (current amps) small joke, is won't work with incan and will work less well with vertical filament.

Proof is in the pics, have a look. The 62138 with its vertical filament looks far better than 64625, which have not posted pics of 64625 but will. Look at the 62138 pic not a trace of filament shadow in that beam.

The mind set, current wisdom among modders somehow got locked into beliving something was not possible, something did not work and drew a conclusion based on experience rather than logic. 

Why it works with incans. is the same reason aspherical lens work with LEDS. And that is there is a relationship between curvature\wavelength of lens, and distance of lens to bulb. Therefore, since one aspherical lens worked best with LEDS (forget which now) as oppossed to one a few mm different reason leads to the conclusion that with an incan. bulb given the correct wavelength and distance of lens to bulb it would be stunning.

I can not explain the physics of why it works you have more ability along those lines. What is apparent is in the pic at top of this thread.

I am going to bed.
Cheers, jim



DM51 said:


> There was a previous thread where someone actually used an aspheric lens with an incan, but I can't find it. In the same way as with the LED pattern, there was a clear projection of the actual shape of the filament.
> 
> An aspheric lens is designed to work best with a point source of light. The principle is similar to using an accurate reflector – it will work best with small sources of light, which is why the best-throwing pencil-beam lights are those with short-arc bulbs (for example, the Maxa Beam).
> 
> ...


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## jimjones3630 (Nov 10, 2007)

*Re: Precision Optic lens for incandescent flash lights?*

64625 with its horizontal filament may have just as culmenated a beam as the 62138 given proper lens wavelength and lens to bulb distance. 
62138




64625 doesn't show as well in pic but some filament shadow noted.


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## DM51 (Nov 10, 2007)

*Re: Precision Optic lens for flash lights?*

Thanks, Jim - I completely missed that link in your post #4. That is a very impressive light!

It is also a very interesting result. I would guess that the vertical filament, by being partly defocused, has the beneficial side-effect of eliminating the artifacts. Whatever the case, it clearly works, and I'm glad to have been proved wrong.

What is the ratio of hotspot diameter to distance? With my LED + 52 mm aspheric the ratio is about 1:40, so for example at 100 feet the projected LED image is ~2½ feet across. If the figure for your incan is anything approaching that 1:40, it should be an absolutely astounding thrower.


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## LuxLuthor (Nov 10, 2007)

*Re: Precision Optic lens for incandescent flash lights?*

I'm guessing what is happening to give a good result, is JJ used a lens with a focal length of 250mm (10") which would mean that a light point 10" behind the center of the lens would be in perfect focus (think the LED Aspherical projects).

The fact that the filament light source is in the forward part of the cone, may still look like a "point light source 'blob'" The lens cannot tell if the light source is back 10" or back a couple inches. The less thickness and convex surface as compared to the LED Aspherical 1D/1C projects, likely has this incan filament appear in effect as a larger, less well defined light source as if a smaller source would have been placed back 250mm.

The light does not get as sharply/acutely refracted in JJ's 250mm focal length as it would in the short 37mm focal length distance used for the LED's. Here is my crude drawing to illustrate the idea, and finding the focal length of each lens.


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## DM51 (Nov 10, 2007)

*Re: Precision Optic lens for incandescent flash lights?*

I may be missing something here - I didn't see any mention of a 250 mm focal length.

From my (rudimentary) knowledge of physics, your idea in that diagram wouldn't work. If the object isn't at the focal length, it won't be in focus. If the bulb filament was where you put it, i.e. at a shorter distance to the lens, the light will pass through the lens but would then keep on diverging (spreading out). 

The lens would have a refractive effect, but the beams would hit the lens at too wide an angle and there would not be enough refraction to bring them parallel. If on the other hand the filament was at a further distance than the focal length, the beams would strike the lens at too narrow an angle, and they would be over-refracted. This would mean they would cross over after they had passed through the lens – and then after crossing over, they would again diverge.

It is only at the focal length that you will achieve parallel beams. If you are slightly under (in front) or slight over (behind) the focal length, there will be divergence, and therefore some blurring. The further away from the focal length, the worse the blurring. 

Caveat to ALL the above – I may possibly be talking TOTAL nonsense, lol. I’m very ready to be corrected if I’m wrong!

But what Jim seems to have managed is to harness a slight blurring effect by using a vertical filament, so part of the filament (half-way down) is in focus and the rest (nearer and further) very slightly out of focus, and therefore slightly blurred. He has used this very slight blurring to eliminate the artifacts you would otherwise expect to see, but at the same time without losing too much through blurring. 

It’s a very effective result, and I’d love to know what the spot size to distance ratio is. I guess we’ll have to wait till he’s had a night’s sleep!


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## VidPro (Nov 10, 2007)

*Re: Precision Optic lens for incandescent flash lights?*



DM51 said:


> It’s a very effective result, and I’d love to know what the spot size to distance ratio is.


 

me too, and i also would like to know more about any use of the Reflector in this application or in the led applications.
people have mentioned having or not having the reflectors in, and were the light from the reflector comes out. but i cant grasp it. here i put a reflector in, and a bit more light moves foreward, but its all over the place.

i can defocus the cree led pattern easily for an 18" beam at 15feet with the lens everyone liked most. even go to very wide beam, but its not a lazer untill its a projection of the emitter.

he told us that there is still minor artifact, but the picture is to Blazingly bright to see any artifacts in the sun center there.


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## DM51 (Nov 10, 2007)

*Re: Precision Optic lens for incandescent flash lights?*



VidPro said:


> people have mentioned having or not having the reflectors in, and were the light from the reflector comes out. but i cant grasp it. here i put a reflector in, and a bit more light moves foreward, but its all over the place.


Light coming off the reflector will go through the lens, but because it is not coming directly from the focal point, it will be spread out by the lens and you will see it as spill. So the reflector isn't any use for concentrating the light when you've got an aspheric, but it does add spill. I hope that makes sense - it's the best way I can describe it.


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## jimjones3630 (Nov 10, 2007)

*Re: Precision Optic lens for flash lights?*

David, 
thanks for helping me learn something. Don't know what the ratio is but will measure it tonight and let you know.

Jim



DM51 said:


> Thanks, Jim - I completely missed that link in your post #4. That is a very impressive light!
> 
> It is also a very interesting result. I would guess that the vertical filament, by being partly defocused, has the beneficial side-effect of eliminating the artifacts. Whatever the case, it clearly works, and I'm glad to have been proved wrong.
> 
> What is the ratio of hotspot diameter to distance? With my LED + 52 mm aspheric the ratio is about 1:40, so for example at 100 feet the projected LED image is ~2½ feet across. If the figure for your incan is anything approaching that 1:40, it should be an absolutely astounding thrower.


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## jimjones3630 (Nov 10, 2007)

*Re: Precision Optic lens for incandescent flash lights?*

VidPro,
The reflector is in as usual, it's a smo camless. Reading your post got an idea. Took the lens and placed it in 2"deep reflector hotwire with 8xNiMh and 1164. lens went from 12mm distance to bulb with usual reflector to 45mm distance to bulb in deep reflector. Hot shot on wall 5" rough circle to 38" perfect circle in 2" deep reflector at 21feet distance from light to wall.

One night while working up this lens project, don't recall which lens but one of aspherical samples here, was foggy a bit and could see in front of flashlight about 12-18 inch the beams cross over and then ran parrallel

David distance outside from flash light to side of house 33ft. Hot spot about 48".

those aritfact you reference below I only saw when using 64625 which did not quite have the fit as the reflector was drilled for 62138 which is tight fit 64625 is larger diameter.
jim



VidPro said:


> me too, and i also would like to know more about any use of the Reflector in this application or in the led applications.
> people have mentioned having or not having the reflectors in, and were the light from the reflector comes out. but i cant grasp it. here i put a reflector in, and a bit more light moves foreward, but its all over the place.
> 
> i can defocus the cree led pattern easily for an 18" beam at 15feet with the lens everyone liked most. even go to very wide beam, but its not a lazer untill its a projection of the emitter.
> ...


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## VidPro (Nov 10, 2007)

*Re: Precision Optic lens for incandescent flash lights?*

*got locked into beliving something was not possible, something did not work and drew a conclusion based on experience rather than logic.* 

we were just waiting for you to show us how to do it 
just like i am hoping that more Fresnel lenses are tested for the low heat applications, and as a "snap-on" changer
Quickbeam and Nereus have tested some stuff 
https://www.candlepowerforums.com/threads/176821 

---- a bit off topic---
did you ever notice , that when newton "invented" gravity, defined it or theorised about it, that sorta after that moment, the idea of it being a mystery to explore, exploit, or understand its corelation to and with other things was lost. 
it is entered into the calculations, put on the charts, understood to the aspect of what is thought to be known about it, and stymied. everything we know about gravity is stuffed in "the book" , and any out of box thought is discarded. somewhere out there is a gravity beyond Newton. It will only take a Apple to land on someones head before we know what it is. then THAT will become old school passive knowledge again.


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## AlexGT (Nov 10, 2007)

*Re: Precision Optic lens for incandescent flash lights?*

So for let's say a FM 2.5 inch throw master, what would be a good focal length to buy? I see surplusshed have a wide variety in sizes that would be drop in replacements.

AlexGT


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## jimjones3630 (Nov 10, 2007)

*Re: Precision Optic lens for incandescent flash lights?*

well, as I posted earlier today, using a FM 2" deep reflector-greater bulb to lens distance but still worked with said lens. I was sad to have to mail it off with the mod I sold as is my last one then new order arrives.

Alex I would start with that lens or one with close specs.




AlexGT said:


> So for let's say a FM 2.5 inch throw master, what would be a good focal length to buy? I see surplusshed have a wide variety in sizes that would be drop in replacements.
> 
> AlexGT


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## jimjones3630 (Nov 11, 2007)

*Re: Precision Optic lens for incandescent flash lights?*

VidPro,

I have read many of Nereus threads and marveled at his work. Have an open mind regarding Fresnels with low heat mods. I firmly believe necessity is the mother of invention. 

The heat generated by current incan mods is a driving force as more lens broke, reflectors distroyed. It's an exciting time and challenging time to not get trapped in the box. More percisely not to shut the door ourselves. 

Your sound like a philosopher and romantic who not only is sensitive to, not only aware of but savors the mystic and good for you. Memento mori!
jim



VidPro said:


> *got locked into beliving something was not possible, something did not work and drew a conclusion based on experience rather than logic.*
> 
> we were just waiting for you to show us how to do it
> just like i am hoping that more Fresnel lenses are tested for the low heat applications, and as a "snap-on" changer
> ...


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## LuxLuthor (Nov 11, 2007)

*Re: Precision Optic lens for incandescent flash lights?*

DM51, I'm no expert on lenses....but I don't agree with the theory about my drawing...except that to see the detail of a light source (like the LED Aspherical mag) it would need to be back at the focal point. The lens that JJ was talking about (after I found it) does have a 250mm focal length, so I didn't pull that out of the air.

His beam spot is not "in focus" like the LED Asperical mod...which shows the individual circuit lines and LED square edges. Rather, JJ's thinner, less convex aspherical is taking the filament "blob of light" and refracting it into a better shaped beam than a standard Borofloat.

Imagine you are standing behind JJ's lens, outside of a Mag, behind the 250mm focus point origin. Then imagine you put a tiny, very bright spherical light source about the size of a head of a pin exactly at the 250mm focal point.

As that point of light shines forward toward the lens, the intense head of a pin would spread into a cone (with brightest appearing in center...just like when you shine your flashlight outside)...and closer to the lens the speck look like a larger somewhat diffused "blob" of light...as it gets closer to lens. My theory is that the incan filament is simulating a blob of light that the lens thinks is coming from much farther back. The light rays are traveling forward towards the lens...whether or not the light source is at the exact focal length 250mm distance does not disqualify the lens refracting the way it is designed to. 

This is consistent with JJ's observation. His wall beam is not in focus, as you are not seeing detail of the filament. It is just more in a focussed beam than without the lens.


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## DM51 (Nov 11, 2007)

*Re: Precision Optic lens for incandescent flash lights?*

OK, I think maybe I've got it now. Thanks for that explanation. 

If the filament was right back at the focal point, it would be projected as a giant image, the same as happens with the in-focus LED aspheric. 

However, he has placed it nearer the lens. This has the effect of keeping it out of focus, so there are no artifacts, but the lens still refracts the light into a reasonably close beam, even if it isn't quite as tight as it would be at the focal point.

I think this would explain the very nice artifact-free hot-spot, and the spot diameter / distance ratio of ~1:8, which is not as tight as the LED aspheric but still impressive.

I hope I've got it right this time. But anyway, the important thing is that it _WORKS!_


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## jimjones3630 (Nov 11, 2007)

*Re: Precision Optic lens for incandescent flash lights?*

David, did you figure the ratio when using 2" deep reflector? posted the measurement above.

The distance pics are very impressive to me using this lens. Only have one which is in the sales ad, reminds me of a 3" reflector with smo finish but a wider spot.




DM51 said:


> OK, I think maybe I've got it now. Thanks for that explanation.
> 
> If the filament was right back at the focal point, it would be projected as a giant image, the same as happens with the in-focus LED aspheric.
> 
> ...


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## DM51 (Nov 12, 2007)

*Re: Precision Optic lens for incandescent flash lights?*



jimjones3630 said:


> David, did you figure the ratio when using 2" deep reflector? posted the measurement above.
> 
> The distance pics are very impressive to me using this lens. Only have one which is in the sales ad, reminds me of a 3" reflector with smo finish but a wider spot.


The only thing I really measured was the hotspot size to distance ratio on my own LED aspheric Mag1C, which has a stock reflector. 

I have really only been discussing the principles of focus / refraction / lenses etc, not the actual figures - explaining roughly how it works as far as I can recall it, without going into detailed measurements. 

It would take a mathematician/physicist with a serious knowledge of refractive indices and geometry to run the numbers on any of this stuff - way beyond me, I'm afraid!


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## jimjones3630 (Nov 12, 2007)

*Re: Precision Optic lens for incandescent flash lights?*

David,

I am learning from you as we go, and I need to go back reread this from the beginning. and take some photos without the reflector at previous used pic with reflector. 

Money is a limiting factor in any research endeavor. With some research parameters and folks eager to contribute who know what might be discovered

Given the focal length 250 behind the lens is understandable what I have noticed. When the bulb is not perfectly centered in the reflector that gap between bulb and reflector is projected out on the wall as artifact. The best projected images come from the tightest fited reflector leaving none or little space to the bulb. 

The half a filament in and half out appears inconsistant with findings.

So reflector incan. bulb relationship behaves just as Led do with Asphericals. Given Incan\lens fl 250 any thing beweet the lens and its fl would cast it's shadow out the window.

Hope someone with those physics\math ability will help us along. If not, seems reasonable to continue testing lens close to this lens specs and move out from there. 

For instance test a lens with 7-8mm center as opposed to the orginal 5.5mm center. And with less than 3.8mm edge as opposed to orginal 3.8mm edge thickness. I would go in that direction, increased center thickness and thinner edge thickness.

Math or physic could predict which direction to go and save us some money. Or enough folks catch the experimental bug and post their results here since I gave a starting point of reference.


Design wavelength is 546.1, which is determined by ratio of glass curvature.

BK7 glass is common borosilicate crown glass known as _BK7. _ Pyrex discovered in 1915 is a synonym for borosilicate glass. 

This Precision Optic lens is made of the stuff we cpf ers know from experience is the best heat tolerant glass. Since my discovered lens is thicker it has greater heat tolerant than the 2mm thick ones we commonly use.

Hopefully, anyone taking up the work will continue to research within BK7 glass or one with higher heat tolerance. 

jim



DM51 said:


> The only thing I really measured was the hotspot size to distance ratio on my own LED aspheric Mag1C, which has a stock reflector.
> 
> I have really only been discussing the principles of focus / refraction / lenses etc, not the actual figures - explaining roughly how it works as far as I can recall it, without going into detailed measurements.
> 
> It would take a mathematician/physicist with a serious knowledge of refractive indices and geometry to run the numbers on any of this stuff - way beyond me, I'm afraid!


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## Tesla-6 (Nov 12, 2007)

*Re: Precision Optic lens for incandescent flash lights?*

Hi Jim
Can you help with a view please.
This from Surplus shed :

*"Hi Jac,*
*The PL1018 Precision PCX lens, 50.8mm diameter by 254mm focal length is sold out.*
*We have similar ones in stock:*
*PL1106 Precision PCX lens, 50mm dia by 250mm focal length, $5 each*
*PL1103 Precision PCX lens, 50mm dia by 250mm focal length, coated, $10 each (you can have them for $8)*

*Shipping via USPS First Class International Air Mail is $5."*

I would like one for an An Incan & one for LED

Focal length for both light sources vary a lot.

What do you think please.

Cheers
Jac


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## jimjones3630 (Nov 12, 2007)

*Re: Precision Optic lens for incandescent flash lights?*

A cpf member contacted suply shed and they gave recommendations for an out of stock lens. Since SS items are acquired from surplus often they are not able to restock items. 

Then asked what I'd recomend for incan. and Led. I don't do LEDs so looking through their stock here are ones I'd recomend in order, anyone using one of these I would appreciate posting your findings here in this thread.

In order of what I'd try next.

Front focal length is 285mm, rear focal length is 266mm. Has a great bluish/purple Broadband AR coating for 400-700nm.
http://www.surplusshed.com/pages/item/pl1091.html

Front focal length is 201.9mm, rear focal length is 197.4mm
http://www.surplusshed.com/pages/item/pl1019.html

Symmetrical bi-convex lenses are made with the same curve on each side and are used to cancel out coma, distortion and chromatic aberration. 
http://www.surplusshed.com/pages/item/pl1045.html

Front focal length is 285mm, rear focal length is 266mm. Has a yellow/orange Broadband AR coating (not sure which wavelength this was designed for). 
http://www.surplusshed.com/pages/item/pl1086.html


http://www.surplusshed.com/pages/item/pl1146.html

http://www.surplusshed.com/pages/item/pl1100.html

_added 2/13/08_ biconvex 42mm lens with (neg)-250mm FL. It's significance is no denigration of beam quality. Of late, have tried several lens less than 250mmFL with poor results. This -250 FL lens made of BK7 has thick 2mm center with 2.8mm edge. 

_2/13/08 moved from separate post_. Tried out SS # PL1062, listed 100mm focal length. Would not recomend this one could get a hot spot focused but resulted in too much flood and deminished throw.

_2/13/08 moved from separate post_. Tried a 220mm focal length lens that would not recomend.

2/22/08 added..*PRECISION 50MM DIAMETER, 250MM FOCAL LENGTH PCX LENS* 
Made of BK7 glass. Design index is 1.5187, design wavelength is 546.1nm. Edge thickness is 2.2mm, center thickness is 4mm. Centration is 3 arc minutes. Edges are ground and beveled.
http://www.surplusshed.com/pages/item/pl1106.html

and 

*PRECISION FUSED SILICA PCX LENS, 50MM DIA, 300MM FL* 
Made of UV grade fused silica. Edge thickness is 3mm, center thickness is 4mm. Design wavelength is 404.7nm, surface quality is 40-20 scratch and dig.
http://www.surplusshed.com/pages/item/pl1100.html

see post #57 and on for eval of above two lens. 

jim

looking for aspherical for use with leds I'd start here

https://www.candlepowerforums.com/threads/166574



Tesla-6 said:


> Hi Jim
> Can you help with a view please.
> This from Surplus shed :
> 
> ...


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## Tesla-6 (Nov 12, 2007)

Thanks Jim
I am chewing the data over.

Cheers
Jac


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## LuxLuthor (Nov 12, 2007)

I'm afraid I bought out their remaining stock of those [FONT=Arial, Helvetica, sans-serif]PL1018 lens without realizing how many they had left. Sorry.
[/FONT]


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## jimjones3630 (Nov 12, 2007)

Jac look forward to your analysis.



Tesla-6 said:


> Thanks Jim
> I am chewing the data over.
> 
> Cheers
> Jac


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## jimjones3630 (Nov 19, 2007)

*Re: Precision Optic lens for incandescent flash lights?*

Tried out SS # PL1062, listed 100mm focal length. Would not recomend this one could get a hot spot focused but resulted in too much flood and deminished throw.



jimjones3630 said:


> A cpf member contacted suply shed and they gave recommendations for an out of stock lens. Since SS items are acquired from surplus often they are not able to restock items.
> 
> Then asked what I'd recomend for incan. and Led. I don't do LEDs so looking through their stock here are ones I'd recomend in order, anyone using one of these I would appreciate posting your findings here in this thread.
> 
> ...


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## Tesla-6 (Nov 20, 2007)

jimjones3630 said:


> Jac look forward to your analysis.


 
Hi Jim
I bought the PL1091.
Still awaiting it's arrival...!

I am going to sit it infront of a WA1185 & just compare a boro & aspherical
item.
We have a very dark golf course with Zero light pollution nearby which
should be ideal for test.

What seem to be an issue is the lack of quantity of any particular lens.
We could hit upon an ideal with great FL etc, & then find "one lens only"
I guess that near to is close enough.

Lux.
First come, first served on the lens:mecry:
Fact is, you will probably put them to more effective use.
Surplus shed could update their stk quantities.
( hard to knock them when so many internet sites do just the same though !)

Cheers
Jac


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## jimjones3630 (Nov 20, 2007)

Hi Jac,

The 1091 has AR coating covering 400-700nm and may increase transmission of light by 4% more than uncoated. Anxious to hear what you find. You idea might be true and we have not found the "optimim" one. AR coating seems a step in that direction.
http://www.edmundoptics.com/techSupport/DisplayArticle.cfm?articleid=247

Cheers, jim









Tesla-6 said:


> Hi Jim
> I bought the PL1091.
> Still awaiting it's arrival...!
> 
> ...


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## Northern Lights (Dec 3, 2007)

JJ, what have you done?
I do not yet understand the math and physics and looks like you now have committed all my free time to doing just that.
What is that lens I now have and can I get it AR coated? I wonder if anyone can answer if there is any advantage to putting it in line with a UCL which is double coated for AR? JJ, email me the links, please!

Someone posted to me when I built the first 2C size 5761 on 18650s to tell me it could not be done. Guess you have had some traditional wisdom to deal with too. Proof is holding it in your hand!

Let me tell you that is some experiment, it was WOW with my 5761 on the A123's. I tested the light on a dark strait residential road where the homes are set back and sparse vegetation lines the street. With my litho reflector and UCL I can illuminate the pavement and leave shadows in the dim spill beam on both sides of the street and I have a maximum useable distance for the hot spot that is a reference point. Over all I love the light it has met all my expectations for throw and width, the 5761 is a large filament bulb.
With this lens I got adjustable performance that beats my FM cammed reflector on an adjustable light I used to have. Beats my MagCharge with the 5761. MC has a tight beam and the cam only opens a donut and does not really make a good flood to spot option. The most the adjustable focus does is tighten the spot but does not make a floodlight. The A123 powered light is brighter than the NiMh powered MC but the MC throws farther, delivers useable light farther, the Litho reflector will not light up distance objects that the MC will illuminate even with less lumens.
Adjustable performance like I have not gotten ever before. 
Because of some mis-match so you do not have clear crisp image projection you have manage to get a nice smooth hot spot with a legitimate spill around it because I guess it is slightly out of focus or that the foci cannot capture the entire filament. I do not thoroughly understand it yet. But that whether by design or divine, this is the key to the success of your creation! *IT WORKS*, very well actually.
I am able to open the hot spot to covering the vegetation from side to opposite side and illuminating it clearly in a bright useable edge of the hot spot; normally at the maximum useable distance the hot spot covers only the pavement with the vegetation on the side just showing silhouette on my test street. This is a true adjustable flood like a stage light or some types of close work specialty lighting, these all use lenses that I write about. 
I can close that hot spot down a bit tighter than the MC and get more distance than the light with just the UCL and probably more distance than the MC.
I once got and posted the actual results of the MC at 2,272 feet, measured with a laser device. Now I will need to do a side by side on that range and same targets again and see if my little 3C belt light beats the MC in throw.
Pointing the beam to the sky I can see the beam in the dirty air open and close according to the position of the bell. 
This is the best flood to spot system I have ever encountered. I definitely can use those properties of close smooth flood to tight spot long throw all in one light.


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## jimjones3630 (Dec 4, 2007)

Keith, thanks for the evaluation and glad to hear you like the lens.

Since this lens was sold out, listed now as in stock but would call first they have history of not keeping web pages up to date. http://www.surplusshed.com/pages/item/pl1018.html 

they do have some which are AR.

Tried out SS # PL1062, listed 100mm focal length. Would not recomend this one could get a hot spot focused but resulted in too much flood and deminished throw.

Tried a 220mm focal length lens that would not recomend.

In order of what I'd try next.

Front focal length is 285mm, rear focal length is 266mm. Has a great bluish/purple Broadband AR coating for 400-700nm.
http://www.surplusshed.com/pages/item/pl1091.html


Symmetrical bi-convex lenses are made with the same curve on each side and are used to cancel out coma, distortion and chromatic aberration. 
http://www.surplusshed.com/pages/item/pl1045.html

Front focal length is 285mm, rear focal length is 266mm. Has a yellow/orange Broadband AR coating (not sure which wavelength this was designed for). 
http://www.surplusshed.com/pages/item/pl1086.html

http://www.surplusshed.com/pages/item/pl1146.html

http://www.surplusshed.com/pages/item/pl1100.html

So easy to box oneself in by thinking something is not possible or something has to be this way or that way. Perception is not reality nor fact, it is only one and one's own point of view.

Veritatis splendor,
jim



Northern Lights said:


> JJ, what have you done?
> I do not yet understand the math and physics and looks like you now have committed all my free time to doing just that.
> What is that lens I now have and can I get it AR coated? I wonder if anyone can answer if there is any advantage to putting it in line with a UCL which is double coated for AR? JJ, email me the links, please!
> 
> ...


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## Northern Lights (Dec 9, 2007)

Somehere above a comment was made that the reflector does not contribute to the output in the incans. I do not think that is correct and I think I know why JJ's system is working with a useable output. Someone else will need to put the numbers to it. LED and Incan are very different in the method of output. LED is a small almost single point for calculation purposes for light source, actually it is a small finite plane of light in the center of the lens so when focused up you have a lens projecting the image of the LED chip. You could do the same with an Incan filament, remove the reflector, used the correct focal length and you would project the image of a horizontal, radial filament, for an axial filament you have a problem of infinite planes transecting the long filament. 
But with JJ's creation you have not only the point of light coming from the filament you have light coming from the reflcetor. For a reference point lets take a plane through the filament, perpendicular to the axis of the flashlight and intersecting the reflector. You can see by this illustration you have infinite planes of light coming off the reflector above and below the plane of the filament for a horizontal filament but as I explane you will see why it works with an axial filament too. So even if you used a focal length that projected the filament and the co-planar spill beam for that point in the plane you have light above and below that is out of focus. Since JJ is using lenses that have focal points behind the filament the filament image is out of focus and thus can be made larger or smaller by a small amout of movement but they cannot not be focused to present a sharp image which would be seen as "artifacts". The spill beam is out of focus too, the entire infinate source of reflective points lying in the horizontal planes of reflected light are between the true focal point and lense, every infinite plane is forward of the focal point. This is projected onto the target, a white wall so every point of light is compiled of infinate images of refleceted light all out of focus , hence homogeous light in the spill and homogenous light in the hot spot. Everything is out of focus, but kept within bounds of the beam which is composed of two elements, light from the filament and light from the reflector. Keeping within the bound of the beam means the light is collimated and projected parallel from curved source so you have an expanding cone of light with an outer element, the spill and inner element the hot spot. 
At least that is the logic in the way I see it works. Now the next step is to put empirical numbers to it and quantify it to an equation; or just put the darn lens on the light and enjoy the success!


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## jimjones3630 (Dec 23, 2007)

NL, 

thanks for the update and appreciate your effort. In my opinion the addition of this lens to a modded light that cost less than $10 added much to the enjoyment and usefullness of the light.

hoped would have received more feedback from folks who asked me which lens I used and where to get it.

jim



Northern Lights said:


> Somehere above a comment was made that the reflector does not contribute to the output in the incans. I do not think that is correct and I think I know why JJ's system is working with a useable output. Someone else will need to put the numbers to it. LED and Incan are very different in the method of output. LED is a small almost single point for calculation purposes for light source, actually it is a small finite plane of light in the center of the lens so when focused up you have a lens projecting the image of the LED chip. You could do the same with an Incan filament, remove the reflector, used the correct focal length and you would project the image of a horizontal, radial filament, for an axial filament you have a problem of infinite planes transecting the long filament.
> But with JJ's creation you have not only the point of light coming from the filament you have light coming from the reflcetor. For a reference point lets take a plane through the filament, perpendicular to the axis of the flashlight and intersecting the reflector. You can see by this illustration you have infinite planes of light coming off the reflector above and below the plane of the filament for a horizontal filament but as I explane you will see why it works with an axial filament too. So even if you used a focal length that projected the filament and the co-planar spill beam for that point in the plane you have light above and below that is out of focus. Since JJ is using lenses that have focal points behind the filament the filament image is out of focus and thus can be made larger or smaller by a small amout of movement but they cannot not be focused to present a sharp image which would be seen as "artifacts". The spill beam is out of focus too, the entire infinate source of reflective points lying in the horizontal planes of reflected light are between the true focal point and lense, every infinite plane is forward of the focal point. This is projected onto the target, a white wall so every point of light is compiled of infinate images of refleceted light all out of focus , hence homogeous light in the spill and homogenous light in the hot spot. Everything is out of focus, but kept within bounds of the beam which is composed of two elements, light from the filament and light from the reflector. Keeping within the bound of the beam means the light is collimated and projected parallel from curved source so you have an expanding cone of light with an outer element, the spill and inner element the hot spot.
> At least that is the logic in the way I see it works. Now the next step is to put empirical numbers to it and quantify it to an equation; or just put the darn lens on the light and enjoy the success!


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## mudman cj (Jan 31, 2008)

I have a 64625 that I would like to focus to a tighter spot for greater throw. What lens (that is available) would you recommend? Do I need a special bezel or a modification thereof to make this work?


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## jimjones3630 (Jan 31, 2008)

would try one of the ones mentioned in post #37. I have tried others and came back here and posted the results in #37. Have some in route for a Kel-lite with 42mm lens. They are not in #37 as only 52mm or 50mm.

Once evaulated will post results in this thread. If you try any recommended here or not would appreciate posting your results here.
jim



mudman cj said:


> I have a 64625 that I would like to focus to a tighter spot for greater throw. What lens (that is available) would you recommend? Do I need a special bezel or a modification thereof to make this work?


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## Fulgeo (Feb 10, 2008)

Just purchased the following from Surplus Shed:

*PRECISION 50MM DIAMETER, 250MM FOCAL LENGTH PCX LENS* 
Made of BK7 glass. Design index is 1.5187, design wavelength is 546.1nm. Edge thickness is 2.2mm, center thickness is 4mm. Centration is 3 arc minutes. Edges are ground and beveled.
http://www.surplusshed.com/pages/item/pl1106.html

and 

*PRECISION FUSED SILICA PCX LENS, 50MM DIA, 300MM FL* 
Made of UV grade fused silica. Edge thickness is 3mm, center thickness is 4mm. Design wavelength is 404.7nm, surface quality is 40-20 scratch and dig.
http://www.surplusshed.com/pages/item/pl1100.html

When I get these lenses in hand I will post my results. I am hoping that the slower 300MM FL will give more throw. In Telescopes slower focal ratios produce less aberrations. These lenses are Plano convex. Flat on one side, curved on the other. I am currious what a true convex lens would do also. Do not be mislead by the "surface quality is 40-20 scratch and dig" This basically defines the state of polish. It does not mean that it was thrown in a bin and bashed around.

One last issue. When you follow some of the links in this tread back to Surplus Shed they appear to be in stock. This might or might not be true. The page is on their site, but there is a good chance it is not current. Just use their lens finder search page. The link is below. Sort of fun to take a look at all the goodies.
http://www.surplusshed.com/lens.cfm


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## jimjones3630 (Feb 10, 2008)

Fulgeo,

Thanks for the evaluation. Very interested to hear your results. I think the frist lens listed has promise, and the second may even be better.

Interesting your comments on convex lens. Just finished a 42mm bi-convex with -250mm FL. It does not have all the properties of the 254mm but does not deminish the quality of the beam either. It is thicker than usuall 2mm borofloat lens so will have increaded heat tolerance and hopefully act as a larger heat sink. I do believe it takes some artifact out of the beam.

I am familiar with surface polishing quality quantification.

Yes the links are out dated, I have order some in the past and paid via paypal then got notice from SS out of stock. They promptly refunded my money. Overall, except for outdated links I am pleased with their customer service. and the prices can't be beat.

You can make note of the lens properties and shop around at other optic supply stores. what I've found is always higher prices.



Fulgeo said:


> Just purchased the following from Surplus Shed:
> 
> *PRECISION 50MM DIAMETER, 250MM FOCAL LENGTH PCX LENS*
> Made of BK7 glass. Design index is 1.5187, design wavelength is 546.1nm. Edge thickness is 2.2mm, center thickness is 4mm. Centration is 3 arc minutes. Edges are ground and beveled.
> ...


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## Fulgeo (Feb 11, 2008)

Jim,

Thanks for starting this thread.

In your post you said "Just finished a 42mm bi-convex with 250mm FL. It does not have all the properties of the 254mm but does not deminish the quality of the beam either." If I follow you, are you saying you would choose a Plano-Convex over a Bi-Convex lens, everything else being equal?

I think you have made a great find here. Surplus Shed is selling these lenses for $5-$10 dollars typically. We have to purchase a glass lens for our mods anyway. The BK7 "crown" glass is not as heat resistant as Boro Float, if they were both flat lenses of equal size. Since the BK7 lenses have more thermal mass I think I would give them the nod over the Boro Float heat resistance wise. The BK7 is definitely the better glass for lenses. It has a lower Refractive Index. Sorry if I state the obvious as if it were inspirational.

Happy Modding!


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## jimjones3630 (Feb 11, 2008)

Fulgeo,

Your welcome, I have a lot of fun with our hobby. Theory, hypothesis, debate, research and testing is a process that works better(quicker) when more people participate. So, thank you Fulgeo for you contribution.

I thought from the beginning there was more than one aspherical lens which will give a desirable result in conjunction with incandescent mods.
The scope of this development is beyond my ability to adequately pursue since I do not want to make this my life time work. So I opened it up at the beginning and started this thread.

Fulgio the biconvex 42mm lens is (neg)-250mm FL. I corrected my mistake in post above. It's significance is no denigration of beam quality. Of late, have tried several lens less than 250mmFL with poor results.
Given the results so far, Yes I would choose one with a FL greater than 250 either positive 250 or neg 250.

This -250 FL lens made of BK7 has thick 2mm center with 2.8mm edge. 
Fulgeo, some don't know the obvious and a refresher once in awhile helps. This lens as you pointed out is both clearer, more transmitted light because of it's Refractive Index and greater heat tolerance because of it's thickness.

So, for the same price you can have a window less prone to break with high heat, and clearer lens. If it increases or decreases throw it's so small I do not notice. 

I would recommend this lens for use in any mod that would normally use a 2mm borofloat flat window.
jim



Fulgeo said:


> Jim,
> 
> Thanks for starting this thread.
> 
> ...


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## jimjones3630 (Feb 13, 2008)

Today tried out a positive meniscus lens, 42.4mm x 4,000mm FL. 4,000 with 3 0s. 

This lens did not have any denigration of beam quality, so many have, but did not replicate the percision round focus beam as orginal lens. I think this lens is an alternative choice for lights with 42mm size window since is thicker 4.5mm and may have higher heat tolerance than soda glass or borofloat of less thickness. It is not made of BK7 and is half the cost of 42mm biconvex lens in previous post.
jim


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## Ctechlite (Feb 13, 2008)

On a whim I ordered these for no apparent reason than their diameter. I will let you know how they are. They were also pretty inexpensive and possibly cheap as well.

SKU: PL1106
PRECISION 50MM DIAMETER, 250MM FOCAL LENGTH PCX LENS
http://www.surplusshed.com/pages/item/pl1106.html

SKU: L4498
Lens: DCX, Dia: 51, Focal: 286, Coated


SKU: L7022
Lens: PCV, Dia: 49.9, Focal: 253, Coated


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## jimjones3630 (Feb 13, 2008)

I always like when cheap and inexpensive. PCV is plano concave which have not tried or heard any reports. Looking forward to hearing how it does.




Ctechlite said:


> On a whim I ordered these for no apparent reason than their diameter. I will let you know how they are. They were also pretty inexpensive and possibly cheap as well.
> 
> SKU: PL1106
> PRECISION 50MM DIAMETER, 250MM FOCAL LENGTH PCX LENS
> ...


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## jimjones3630 (Feb 13, 2008)

Tried out ss# L7147 NMN, 42.6mm x -235.3 focal length, CTD (coated). it is difficult to find at SS. a search of stock doesn't bring it up, but will come up as an ordered item.

this neg menistic lens made a flood light effect, much like a heavy stippled reflector might. Very surprising as first neg menistic I've tried.

Reverse the lens concaved side out and it makes a great lens. focused the beam in a more coheasive condensed manner. Need to find where can send a 254 to cut down to 42mm. The neg menistic lens is somewhat remenist of the 254 for those familiar with orginal lens of this thread. It does not produce the perfect circle of light as does the 254 but I think I might like it more than bi-cv.
jim


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## Ctechlite (Feb 13, 2008)

jimjones3630 said:


> Tried out ss# L7147 NMN, 42.6mm x -235.3 focal length, CTD (coated). it is difficult to find at SS. a search of stock doesn't bring it up, but will come up as an ordered item.
> 
> this neg menistic lens made a flood light effect, much like a heavy stippled reflector might. Very surprising as first neg menistic I've tried.
> 
> ...



Re the Red hi-lited text : I think all of the lenses labeled with an L at the beginning are not listed with their own information page, but the ones listed with a PL (maybe P is for premium) get their own information page. But that is just a guess from me trying to find info pages for L lenses and P lenses (very small sample size here...)


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## jimjones3630 (Feb 13, 2008)

That could be true. P lenses are premium, that is posted. can't find anything on L. The lens will show up in shopping cart if place lens number in "shed Quickcart."

Just seems odd, I found it by doing a lens finder parameter search "42mm and that was only parameter I used.

their web site could be more user friendly. can't beat the prices.
jim




Ctechlite said:


> Re the Red hi-lited text : I think all of the lenses labeled with an L at the beginning are not listed with their own information page, but the ones listed with a PL (maybe P is for premium) get their own information page. But that is just a guess from me trying to find info pages for L lenses and P lenses (very small sample size here...)


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## Fulgeo (Feb 14, 2008)

I received my lenses today. Pulled out a few of my mods and started testing. Initially tried 2D Mag Mod AW1111 with cammed MOP reflector. Then I tried AW1185 3D Mag Mod with cammed MOP reflector. Was dissapointed with the results. Could not get a solid beam focus. No solid hot spot. Not to be discouraged I got my AW1185 3D Mag Mod with cammed SMO reflector. Now that was more like it. Gives a much more solid and circular hot spot in the beam. The PCX lenses seem to clean up the beam quite a bit. I noticed the overall beam is slighly ( maybe 15-12% ) smaller. Atleast as projected against the ceiling. Both of the lenses I ordered work fine. I would give a slight nod to the 300mm focal length over the 250mm one. Not sure if it was the effects of the extra 50mm or the coating that was present on the 300mm one or both. Liked the 300mm lens so much it has found a home in my AW1185 3D Mag Mod with cammed SMO reflector. Was wondering what reflectors JimJones and Northern Lights were using for their evaluations? One interesting thing thou was the SMO reflector put on a the 2D with AW1111 did not give an improvement to beam quality. Seemed to have a few shadows ( filament?) in the beam center. I wonder if the results are lamp/bulb specific? I just got in a batch of 5761 and have some A123 on the way. Will be intersted to see what magic the lenses have on the 5761. In closing would say big thumbs up for AW1185 with SMO reflector. Methinks next I will be ordering a meniscus lens or two.



Fulgeo said:


> Just purchased the following from Surplus Shed:
> 
> *PRECISION 50MM DIAMETER, 250MM FOCAL LENGTH PCX LENS*
> Made of BK7 glass. Design index is 1.5187, design wavelength is 546.1nm. Edge thickness is 2.2mm, center thickness is 4mm. Centration is 3 arc minutes. Edges are ground and beveled.
> ...


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## Northern Lights (Feb 14, 2008)

Fulgeo that is very interesting but not surprising the different bulbs acted differently. 
When trying out the 5761s, also try frosting the bulb with Armour Etch. I frost from bottom to up just past the filament on bulbs and leave the top clear. No loss of lumens, just shadows that way. I found it made a difference in the lens I tried to have a frosted bulb.


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## jimjones3630 (Feb 14, 2008)

Fulgeo

thanks for the report. That adds one more to the list which has pos. effect and work with incans. 



Fulgeo said:


> I received my lenses today. Pulled out a few of my mods and started testing. Initially tried 2D Mag Mod AW1111 with cammed MOP reflector. Then I tried AW1185 3D Mag Mod with cammed MOP reflector. Was dissapointed with the results. Could not get a solid beam focus. No solid hot spot. Not to be discouraged I got my AW1185 3D Mag Mod with cammed SMO reflector. Now that was more like it. Gives a much more solid and circular hot spot in the beam. The PCX lenses seem to clean up the beam quite a bit. I noticed the overall beam is slighly ( maybe 15-12% ) smaller. Atleast as projected against the ceiling. Both of the lenses I ordered work fine. I would give a slight nod to the 300mm focal length over the 250mm one. Not sure if it was the effects of the extra 50mm or the coating that was present on the 300mm one or both. Liked the 300mm lens so much it has found a home in my AW1185 3D Mag Mod with cammed SMO reflector. Was wondering what reflectors JimJones and Northern Lights were using for their evaluations? One interesting thing thou was the SMO reflector put on a the 2D with AW1111 did not give an improvement to beam quality. Seemed to have a few shadows ( filament?) in the beam center. I wonder if the results are lamp/bulb specific? I just got in a batch of 5761 and have some A123 on the way. Will be intersted to see what magic the lenses have on the 5761. In closing would say big thumbs up for AW1185 with SMO reflector. Methinks next I will be ordering a meniscus lens or two.


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## Fulgeo (Feb 16, 2008)

Thanks for the feedback guyz. I have added Armour Etch to my list of materials to pick up. JimJones and Northern Lights may I ask what types of reflectors you guys have tested with the the lenses? My results with a AW1185 and lens are:

KIA cammed MOP 8.4m opening - No usefull improvement.

FiveMega cammed MOP 10.5mm opening - So So.

FiveMega cammed SMO 12.7 opening - Good to Excellent!


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## Northern Lights (Feb 16, 2008)

Fulgeo said:


> Thanks for the feedback guyz. I have added Armour Etch to my list of materials to pick up. JimJones and Northern Lights may I ask what types of reflectors you guys have tested with the the lenses? My results with a AW1185 and lens are:
> 
> KIA cammed MOP 8.4m opening - No usefull improvement.
> 
> ...


 
Older style, mag copy, FM smooth, usually a long throw and Litho123 smooth which have a little less throw.

I find with the 254mm on the litho I can get a very good spot/flood function with the 5761, with the FM the spot throw is not as good and the flood a little to wide for a large hot spot thus dimmer overall, too much area to spread it. 

These same reflectors with the 64430 chinese bulb had the affect with the lens to tighten it abit but the bulb is a very wide flood to start with.


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## jimjones3630 (Feb 16, 2008)

Fulgeo

Using the 254 fl lens and Tungsram 56580 which compared to the Chinese 64430 is even more flood. I used a litho (carley) smo with + results. What really helped is a 2" deep FM reflector which started out as smo but ended up with a little bit of stipple effect (easy to do with 250w 24v bulb pushed to 29v).

With the 5761 I recently discovered, probable the last one in cpf, the all steel magcharger reflector which looks smo. I really really like this reflector. It throws great and with a little armour tech to the bulb the artifact is gone. 

I used the magcharger reflector as a replacement for a smaller 42mm head kel lite. Needed cut down to size but what a difference running the chinese 64430 in front of 3xA123 the 5C kel is shorter than 3D mag. 
jim



Fulgeo said:


> Thanks for the feedback guyz. I have added Armour Etch to my list of materials to pick up. JimJones and Northern Lights may I ask what types of reflectors you guys have tested with the the lenses? My results with a AW1185 and lens are:
> 
> KIA cammed MOP 8.4m opening - No usefull improvement.
> 
> ...


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## Northern Lights (Feb 16, 2008)

My mag charger 5761 still retains the cam action so I never put the 254 lens into it. I will try that in the next day or so, I have one more lens left and I will report back! Here is my experience with that reflector and 5761:
2,272 foot throw from my MagCharger!


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## jimjones3630 (Feb 16, 2008)

Do you still have the laser to measure with?



Northern Lights said:


> My mag charger 5761 still retains the cam action so I never put the 254 lens into it. I will try that in the next day or so, I have one more lens left and I will report back! Here is my experience with that reflector and 5761:
> 2,272 foot throw from my MagCharger!


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## Northern Lights (Feb 16, 2008)

jimjones3630 said:


> Do you still have the laser to measure with?


Strange you asked that. I just came in from my "residential street test bed" and was impressed that this Mag Charger is a spot light with the 254mm lens and 5761 of 7.2 Vbat, 12 Powerex 2700 AA at 5400 mAh. 

I am working a graveyard shift tomorrow night and decided I would do just that! I will take this out to the same place with the LIDAR and test it again on the same targets and see if it is better this way. I like what I see so far!


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## Fulgeo (Feb 16, 2008)

Thanks for the reflector info guyz. Just put together my first 5761 tonight driven by 2 A123 cells. Seems to have a better spot than the AW1111 and AW1185 can throw up with the same reflectors and boro lenses. The 5761 seem to respond better to the aspherical lenses also. The light output of the 5761 seems to be slightly less than the AW1185 but definitely brighter than the AW1111. I account this to the 6.6v output of the 2 A123 cells, but hey no insta flash. Still need to do some resistance moding to the 5761 also. One thing to note the 5761 got good results with the lenses reguardless of SMO or MOP reflector. The 5761 does not seem to be as picky reflector wise.


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## Northern Lights (Feb 16, 2008)

Fulgeo said:


> Thanks for the reflector info guyz. Just put together my first 5761 tonight driven by 2 A123 cells. Seems to have a better spot than the AW1111 and AW1185 can throw up with the same reflectors and boro lenses. The 5761 seem to respond better to the aspherical lenses also. The light output of the 5761 seems to be slightly less than the AW1185 but definitely brighter than the AW1111. I account this to the 6.6v output of the 2 A123 cells, but hey no insta flash. Still need to do some resistance moding to the 5761 also. One thing to note the 5761 got good results with the lenses reguardless of SMO or MOP reflector. The 5761 does not seem to be as picky reflector wise.


Depending on your internal resistance, both JJ and I have measured Vbulb on the A123 on the 5761 at 6.9Vbulb, do to the fact the nominal is 3.3 it is because these things do not dip very much with 5.43 amps draw.
I thought I noticed the Welch Allan 1185 as being brighter too until I realized something.

Lumens over area, think of it as a fire hose. If you concentrate the stream the force seems greater than if you open it. The WA1185 is about 80-100 lumens less than the 5761 but the hot spot is smaller, the beam is concentrated by the design of the bulb so you are putting those lumens in the center. That is what a LUX reading does, lumens is the total amount of light. Go back to the firehose analogy. If your hose is putting out the same gallons per minute (lumens) the concentrated stream seams to be more presure, (brighter). That is what is happening between the two. The center is probably brighter but you have less overall light with the 1185 and your eye off course just focuses on the brightness. You can get the same effect by using a 5761 with the lens next to one without the lens. I have seen that and it convinced me that is what I was seeing in the 1185 too. So if you are interested in a bright center spot, use the WA1185 over the 5761, but if you generally want more light over more are, use more lumens. 

Try looking at distant objects and see if there is more illumantion total with the 5761 and that will tell you if you got more "water" out there.

I hope this is what really is happening with your set up otherwise I look a little foolish but that is what I found with mine. I appreciate your work with all the tests. Together we all have a very interesting project going here.


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## Northern Lights (Feb 18, 2008)

Northern Lights said:


> Strange you asked that. I just came in from my "residential street test bed" and was impressed that this Mag Charger is a spot light with the 254mm lens and 5761 of 7.2 Vbat, 12 Powerex 2700 AA at 5400 mAh.
> 
> I am working a graveyard shift tomorrow night and decided I would do just that! I will take this out to the same place with the LIDAR and test it again on the same targets and see if it is better this way. I like what I see so far!


 
I am very disappointed but I understand what is happening.

My first shot at the 2272 foot away target was a miss! Where did all that light go?

So I backed down to 1900-2000 feet targets, not white walls but tan colored large walls of aircraft hangers, large enough to take L1011s, 747s, very large buildings so you can see the affects of a light for that far away. 

Still it was disappointing and I could only notice the light after I removed the 254mm aspheric lens from the bezel.

I went down to 500-700 feet and then I got a handle on what was happening. :twothumbs

I found with the Litho123 smooth reflector on the 5761 bulb, adjusted in depth of the socket for the bulb to reach tight spot with two turns up from dead bottom if I added the 254 mm aspheric I could extend useable hot spot about 50-60 yards. 

But that system did not work with the 64430 bulbs in a different light. It is apparent that the benefits of the aspheric are dependent of bulb and reflcetor characteristics. 

I observed these effects. When shining the 5761 in the Litho123 reflector up I can see the beam in the dirty air and can see whe focal point where the beam is tightest and after that it opens up and an almost parallel beam is projected.
I do not see this with the Mag Charger. That reflector is deep and has a steep parabolic curve and the beam comes out of it quite strait and parallel without any lens. For that reason it it great for illuminating distant objects, thus the 2,272 foot story. When I put the lens in to that beam I got a great hot spot, intense and tight and an improvement over the Litho reflector. Move out beyond that range and the focus of the lens caused that almost parallel beam now to diverge.

The lens did give me a great spot light but at a predetermined distance that is much closer than it can reach when not focused down to the spot. After the focal point is reached natually the beam diverges. 

Oh, well, we love to play don't we? :grouphug:


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## jimjones3630 (Feb 18, 2008)

NL, 

interesting evaluation. With a given amount of lumens our eyes are easily tricked and your evaluation takes some subjectivity out. The magcharger refleltor due to it's particular shape focuses the beam in a different manner (more coherent) than litho's and is more of a thrower without the aspherical. The 254 improved the throw with litho reflector. To improved the throw with magcharger may need a different FL lens. I have a 4000FL and couple others but are for 42mm diameter head.

Using the 254 with 5761 and magcharger reflector is useful at less than max range. Around here at distances of 200yds or less I like the increase size of the spot. It looks 2-3x or greater. 

With the Chinese 64430 A123x3 in kel lite, cut down magcharger reflector, and 42mm lens I found couple of SS with positive effect as described in previous post here in this thread. The effect is not as nearly pronounced with 254 in full size heads. Both of these lens are at least twice as thick and expect to manage heat more effectively or at least not break. 

NL thanks for the evaluation.



Northern Lights said:


> I am very disappointed but I understand what is happening.
> 
> My first shot at the 2272 foot away target was a miss! Where did all that light go?
> 
> ...


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## jimjones3630 (Feb 18, 2008)

NL, 

interesting evaluation. With a given amount of lumens our eyes are easily tricked and your evaluation takes some subjectivity out. The magcharger refleltor due to it's particular shape focuses the beam in a different manner (more coherent) than litho's and is more of a thrower without the aspherical. The 254 improved the throw with litho reflector. To improved the throw with magcharger may need a different FL lens. I have a 4000FL and couple others but are for 42mm diameter head.

Using the 254 with 5761 and magcharger reflector is useful at less than max range. Around here at distances of 200yds or less I like the increase size of the spot. It looks 2-3x or greater. 

With the Chinese 64430 A123x3 in kel lite, cut down magcharger reflector, and 42mm lens I found couple of SS with positive effect as described in previous post here in this thread. The effect is not as nearly pronounced with 254 in full size heads. Both of these lens are at least twice as thick and expect to manage heat more effectively or at least not break. 

NL thanks for the evaluation.



Northern Lights said:


> I am very disappointed but I understand what is happening.
> 
> My first shot at the 2272 foot away target was a miss! Where did all that light go?
> 
> ...


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## Fulgeo (Feb 22, 2008)

NL,

Went for a walk on a dark night with flashlights in hand. I think you are right on the money. The 5761 put out a nice juicy usable beam.



Northern Lights said:


> I thought I noticed the Welch Allan 1185 as being brighter too until I realized something.
> 
> Lumens over area, think of it as a fire hose. If you concentrate the stream the force seems greater than if you open it. The WA1185 is about 80-100 lumens less than the 5761 but the hot spot is smaller, the beam is concentrated by the design of the bulb so you are putting those lumens in the center. That is what a LUX reading does, lumens is the total amount of light. Go back to the firehose analogy. If your hose is putting out the same gallons per minute (lumens) the concentrated stream seams to be more presure, (brighter). That is what is happening between the two. The center is probably brighter but you have less overall light with the 1185 and your eye off course just focuses on the brightness. You can get the same effect by using a 5761 with the lens next to one without the lens. I have seen that and it convinced me that is what I was seeing in the 1185 too. So if you are interested in a bright center spot, use the WA1185 over the 5761, but if you generally want more light over more are, use more lumens.
> 
> ...


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## Fulgeo (Feb 22, 2008)

Just purchased the following from Surplus Shed:

SKU: L6692 Lens: PMN, Dia: 52, Focal: 308, Coated 

SKU: L4498 Lens: DCX, Dia: 51, Focal: 286, Coated 

When I get these lenses in hand I will post my results. I actually ordered two of the SKU:L6692. These lenses are only $4.00 each:thumbsup:


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## jimjones3630 (Feb 22, 2008)

Hey Fulgeo,

Don't they look interesting?

I pick up one of the PRECISION FUSED SILICA PCX LENS, 50MM DIA, 300MM FL you tested. Fused silica glass lens are very expensive due to the clarity of light transmission and low thermal coeffecient, decreased expansion in the presence of heat.
I'm having alot of fun with it comparing to aspherical have on hand.

Looking forward to your report.
jim


Fulgeo said:


> Just purchased the following from Surplus Shed:
> 
> SKU: L6692 Lens: PMN, Dia: 52, Focal: 308, Coated
> 
> ...


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## Fulgeo (Feb 28, 2008)

Fulgeo said:


> Just purchased the following from Surplus Shed:
> 
> SKU: L6692 Lens: PMN, Dia: 52, Focal: 308, Coated
> 
> ...


 
I received the lenses today and here are the results. First off both the SKU: L6692 lenes had small chips on the outside rims. Once screwed into the Mag head this was hidden. Can not really see the chips once mounted and not in beam path. Also the SKU: L4498 was suppose to be a DCX "Double Convex". Double-Convex Lenses have two outward curving faces. This mystery lens seems to be a PMN. Now for the results tested on my 2xA123 5761. Both these lenses improved the beam. The mystery L4498 lens was better than my earlier purchased 250mm focal length PCX lens but it was not as good as my 300mm fused silica focal length PCX lens. The new SKU: L6692 Lens: PMN, Dia: 52, Focal: 308, Coated lens was the best of all. As good or better beam shape as the 300mm fused silica PCX and the beam was whiter! Something is going on here and I am going to take a guess. I think that because the PMN lens design uses less glass material to deliver the same or better focal length, not as much light is lost going thru the lens. I feel as we walk the focal length up we are getting more throw. I need to see if I can find myself a 500mm+ focal length PCX or PMN. 

I put the boro lens back on the 5761 for comparison and now I can not live without a PCX or PMN lens on it. I would not bother putting a PCX or PMN lens on a AW1111. Summarized results:

AW1111: SMO or MOP reflector does not matter, lens does not help much

AW1185: MOP reflector SoSo, SMO noticably better, good results.

5761: SMO or MOP reflector excellent results. Get one you should love it.


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## jimjones3630 (Mar 1, 2008)

Fulgeo, 
thanks for the great evaluation. Sounds like L6692 you like the quality of beam the best over 300mm PCX. That it looks whiter is very intriguing.

Each lens evaluated I copy and paste into #1 post of this thread. think will make for easier review of all the lens.
thanks for you work. I'll take your lead on testing longer FL lens with my next order from SS.
jim



Fulgeo said:


> I received the lenses today and here are the results. First off both the SKU: L6692 lenes had small chips on the outside rims. Once screwed into the Mag head this was hidden. Can not really see the chips once mounted and not in beam path. Also the SKU: L4498 was suppose to be a DCX "Double Convex". Double-Convex Lenses have two outward curving faces. This mystery lens seems to be a PMN. Now for the results tested on my 2xA123 5761. Both these lenses improved the beam. The mystery L4498 lens was better than my earlier purchased 250mm focal length PCX lens but it was not as good as my 300mm fused silica focal length PCX lens. The new SKU: L6692 Lens: PMN, Dia: 52, Focal: 308, Coated lens was the best of all. As good or better beam shape as the 300mm fused silica PCX and the beam was whiter! Something is going on here and I am going to take a guess. I think that because the PMN lens design uses less glass material to deliver the same or better focal length, not as much light is lost going thru the lens. I feel as we walk the focal length up we are getting more throw. I need to see if I can find myself a 500mm+ focal length PCX or PMN.
> 
> I put the boro lens back on the 5761 for comparison and now I can not live without a PCX or PMN lens on it. I would not bother putting a PCX or PMN lens on a AW1111. Summarized results:
> 
> ...


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## Fulgeo (Mar 1, 2008)

JimJones,

Thanks for the reply. Think we can draw the conclusion that with a 5761 and a MOP reflector any PCX or PMN lens of 250mm-300mm+ will work? I just wonder how much over 300mm we can go. I think we could also do a dual lens setup. One small lens infront of the bulb and one in the normal window. Need to do some research but I think we could get a variable spot where one could walk the desired spot to the target. 

Just purchased the following from Surplus Shed:

SKU: L8155 Lens: NMN, Dia: 52, Focal: -364

When I get this lens in hand I will post my results. I am thinking I can flip it around and use it as positive 364mm focal length.


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## IcantC (Mar 1, 2008)

Read the whole thread and has good info, anyone have any ideas on what to try for a ROP?

Thanks


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## jimjones3630 (Mar 1, 2008)

IcantC,

Have tried ROP HO, thought posted results here. anyway, the tip of the HO bulb is projected out casting a shadow into the beam. The fact it does so does not seem to support the theory of how aspherical work with incans.

Loosely stated it works because the FL is either behind the lens or in front of the lens far enough so the inability to obtain sharp focus culminates the beam into a huge hot spot which is out of focus . My orginal hypothesis was there is a relationship between curvature of the lens and distance between lens and bulb. We now know that there is a relationship between incan bulb, lens, and reflector. Unlike LED mods with aspherical lens the reflector has no impact on the beam. 

ROP HO is the only bulb I found that clearly had adverse beam affect with the original 254FL lens.
jim



IcantC said:


> Read the whole thread and has good info, anyone have any ideas on what to try for a ROP?
> 
> Thanks


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## Techjunkie (Mar 14, 2008)

jimjones3630 said:


> Fulgeo,
> thanks for the great evaluation. Sounds like L6692 you like the quality of beam the best over 300mm PCX. That it looks whiter is very intriguing.
> 
> Each lens evaluated I copy and paste into #1 post of this thread. think will make for easier review of all the lens.
> ...


 
Jim, based on Fulgeo's post, I ordered sku L6692 and I received it yesterday. I have to say, I absolutely love it. Sadly, it chips very easily. I dropped it on a mica countertop from less than a foot above and a decent sized chunk of glass cleaved off. (So handle with care.)

It still gives great shape to the beam though, and _barely_ affects throw. It's also a _really_ pretty lens to look at - so transmissive, you almost wouldn't be able to see it if not for the huge chip. Shots below.














Beamshot (ISO200, F5.6, 1/4sec, WB-tungsten)
Mag 2D modded with WF-500 bulb assembly and 8AA with ordinary flat glass lens:





Beamshot
Same flashlight modified with L6692 lens same camera settings:





Beamshot
Now closer at about 15ft. from the wall instead of 30ft:





You can see from the beam shots that L6692 improves the roundness of the beam pattern and increases the size of the hotspot. As it happens, the camera already did a lot to improve the appearance of the hotspot prior to adding the new lens. The difference between lenses is much more noticable in person.

Also worth mentioning, I had to grind down the Mag threads and reflector a bit to give lens a better fit. Now the lens ring perfectly tightens down all the way with flat glass installed and with L6692 installed, tightens down all but 1mm from fully tightened.


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## Fulgeo (Mar 21, 2008)

Fulgeo said:


> Just purchased the following from Surplus Shed:
> 
> SKU: L8155 Lens: NMN, Dia: 52, Focal: -364
> 
> When I get this lens in hand I will post my results. I am thinking I can flip it around and use it as positive 364mm focal length.



I received the L8144 lens and it will not work for this application. The lens diameter was 53.3mm and was too large to fit in the mag housing. Will have to find another source of lens because we have exhausted what is currently available at the Surplus Shed. I will do some searching this weekend.


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## jimjones3630 (Mar 21, 2008)

Looks like you didn't get the lens L8155 you ordered. Did they substitute L8144? I have so far received only the lens ordered and not any substitutes.

I have looked for alternative sellors but all I found are too expensive.
http://www.edmundoptics.com/onlinecatalog/displayproduct.cfm?productID=2684
jim




Fulgeo said:


> I received the L8144 lens and it will not work for this application. The lens diameter was 53.3mm and was too large to fit in the mag housing. Will have to find another source of lens because we have exhausted what is currently available at the Surplus Shed. I will do some searching this weekend.


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## Fulgeo (Mar 29, 2008)

Found another supplier and have ordered the following PCX lenses:

Diameter 50.8 mm Focal length 400 mm Edge thickness 3.0 mm.
Diameter 50.8 mm Focal Length 500 mm Edge thickness 3.0 mm.
Diameter 50.8 mm Focal Length 1000 mm Edge thickness 3.0 mm.

They cost $20.80 each plus there was a $15.00 charge for postage. When I get the lenses in hand I will post my results.


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## jimjones3630 (Apr 1, 2008)

Hey don't those looking promising. looking forward to seeing the results.
jim



Fulgeo said:


> Found another supplier and have ordered the following PCX lenses:
> 
> Diameter 50.8 mm Focal length 400 mm Edge thickness 3.0 mm.
> Diameter 50.8 mm Focal Length 500 mm Edge thickness 3.0 mm.
> ...


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## Fulgeo (Apr 4, 2008)

Well I received my lenses today and gave them a test run. Here is the set up. I put together four mag heads all using FiveMega cammed MOP 12.7mm opening reflectors. The lenses used were boro flat, PMN Focal Length 308mm, PCX Focal Length 500mm and PCX Focal Length 1000mm. All mag heads were tested on the same base flashlight mod which was a Mag 2D 2xA123 5761. With this setup I made the following conclusions. The PCX FL 500mm Lens did throw farther than the PMN Focal Length 308mm lens. No suprise. It seems that the spot of light was just projected out farther. I did notice that some of the spot edge definition was lost when projected against a wall at 50'. To be more clear about what I am talking about I mean the contrast between spot and spill. The transition point between the two. With the PMN FL 308mm it was slightly more defined. With the PCX FL 1000mm Lens even more throw was apparent and once again slightly less contrast between spot and spill as mentioned above. I used the forth boro flat lens as a control. I am going to be testing this with Osram bulbs and some SMO reflectors in the future. Would give the PCX FL 500mm & 1000mm Lenses a thumbs up. I just wish I could get some PMN in 500mm or larger because if given the choice I would choose the PMN over the PCX design. I think the less glass material the light has to go thru the better. By better I mean brighter.


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## mudman cj (Jun 4, 2008)

Has anyone tried these long focal length lenses with LEDs? I am sorry if this does not belong in this thread, but everyone else seems to be using lenses with focal lengths designed to tightly focus from a point at the emitter die. 

I am not really after a tiny spot here, but more of a 'circle of light' with *no* spill. Ideally, the beam would project about a 5-10' diameter spot at a distance of about 20-50' (I'm trying to provide ranges to broaden the possibilities). This sounds to me like it may be an application for an optic, but I thought optics generally provided some spill, and I haven't seen a 52mm dia optic. The LED is a Lux III with lambertian emission pattern.


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## Gunner12 (Jun 4, 2008)

It would be similar to a bare LED.

It should give a good sized circle of light with no spill. The circle should be smaller then it is without the lens.

For what you want, maybe something with a shorter focal length will work.


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## Fulgeo (Jun 4, 2008)

Mudman,

Typically the lenses of 33-37mm focal length are used with LEDs to give that pin point of light effect. I have a 34mm focal length lens I purchased from Kiadomain that really projects a Cree Q5 to a point. You get a square ( the LED die ) box of light about 4'x5' or so at 150 yards. Sort of cool and very usuable. Really puts the light where you want it. Now for the effect you are looking for which I believe is less spill and more of a circle of light you could try this from Surplus Shed. http://www.surplusshed.com/pages/item/pl1146.html Just a guess on my part but I bet it would give the results you are looking for. Also note that the lens I bought here from Kaidomain http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=4167 would work for sure atleast with a Cree die. I am able to pin point and also get a big circle of light with little spill just by dialing it in. Nice thing about Kaidomains lens is you do not need a reflector to get the effect. I actually prefer it without one! 



mudman cj said:


> Has anyone tried these long focal length lenses with LEDs? I am sorry if this does not belong in this thread, but everyone else seems to be using lenses with focal lengths designed to tightly focus from a point at the emitter die.
> 
> I am not really after a tiny spot here, but more of a 'circle of light' with *no* spill. Ideally, the beam would project about a 5-10' diameter spot at a distance of about 20-50' (I'm trying to provide ranges to broaden the possibilities). This sounds to me like it may be an application for an optic, but I thought optics generally provided some spill, and I haven't seen a 52mm dia optic. The LED is a Lux III with lambertian emission pattern.


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## mudman cj (Jun 4, 2008)

Thanks guys. I am going to try the one from surplus shed because I prefer that it doesn't stick out as much. This light could be dropped or banged around pretty hard. It also doesn't hurt that its cheaper.


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## jimjones3630 (Jun 9, 2008)

mudman cj said:


> Thanks guys. I am going to try the one from surplus shed because I prefer that it doesn't stick out as much. This light could be dropped or banged around pretty hard. It also doesn't hurt that its cheaper.


 
Mudman interesting to hear you evaluation.


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## mudman cj (Jun 12, 2008)

I got the lens in today and so right away I installed it and took some measurements.

If I tighten the bezel all the way down and therefore minimize the distance from the lens to the LED I get a circle of light with a diameter of about 6' a distance of 5'. This calculates out to a beam angle of 62 degrees. If I loosen the bezel until the O-ring just barely still seals the head of the light, and therefore maximize the lens to LED distance, then I get a circle of light with a diameter of about 6.5' at a distance of 8'. The corresponds to a beam angle of 44 degrees.

I would prefer to have a tighter focus. And now that I have tried this lens I have a better idea of what I want. I think I want a beam angle of between 10 and 25 degrees, with a preference of about 15 degrees. Assuming that the ratio of beam angles I measured will remain the same for a different lens as the bezel is adjusted, then I should expect an adjustment range of 4-6 degrees by turning the bezel. Since I would prefer to have the bezel nearly fully tightened, this makes me think that my ideal lens would be adjustable to give a beam angle from 11-15 degrees. This way, I can be near the lower end of my 10-25 range with the bezel fully tightened, and I can loosen it a bit to tighten it up. If a lens cannot be found that results in this particular range (11-15 degrees), then I would like to find one that gives a beam angle of about 15-21 degrees.

I find it difficult to find lenses I want using the Surplushed search function, so once again I welcome assistance in selecting a lens for my purpose. Thanks again for your help.


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## mudman cj (Jun 14, 2008)

Well, I spent some more time searching around on Surplushed, trying different key words and came up with some more finds. I *may* have found the answer to my own question, though it is not the "perfect" answer because the lenses are not quite the right size. I hope to be able to secure them in place some how. 

The first is item #L3749, a 45mm dia x 54mm FL PCX spherical condenser lens. This one sounds attractive since it has a center thickness of only 6mm, but I am unsure about it since it is not aspherical. What differences might I expect in the beam between a spherical and an aspherical lens like this?

The second one is item #L3688, a 47mm dia x 50mm FL DCX aspheric condenser lens. It is much thicker at 17mm, but since it is a double convex lens I think it should stick out from the bezel no more than the 12mm thick PCX lens I have now. I am attracted to this one because it is aspherical and has a larger diameter than the above lens.

Before I purchase one or both of these lenses I would like to hear your opinions about them. I will be waiting...


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## Fulgeo (Jun 15, 2008)

Hmmm, you did not mention the edge thickness of those two lenses. I really dislike lenses that have an edge thickness of much greather than 3.5mm since they leave a gap in the stock Mag head. I would not purchase the two lenses you mentioned since you need a diameter of 50-52mm to fit the stock Mag head. They would be hard to mount and secure in a stock Mag head. An easier solution would be to purchase the Kaidomain lens. It is $19.95 and 3-4 weeks away. It will perform perfectly as you specified. The down side is it will project out of the stock Mag head a bit and is vulnerable. What I do with mine is use one of those rubber anti-roll adapters on my Mag head. It adds a bit of length and if you pull it out a bit near the end offers protection to the lens. Now I have ordered another lens that might work that cost about $5.00 from another supplier. When I get it in hand if it had the desired effect I will share my results with you. I figure I have about 2 more weeks of waiting for the mail to recieve it. 



mudman cj said:


> Well, I spent some more time searching around on Surplushed, trying different key words and came up with some more finds. I *may* have found the answer to my own question, though it is not the "perfect" answer because the lenses are not quite the right size. I hope to be able to secure them in place some how.
> 
> The first is item #L3749, a 45mm dia x 54mm FL PCX spherical condenser lens. This one sounds attractive since it has a center thickness of only 6mm, but I am unsure about it since it is not aspherical. What differences might I expect in the beam between a spherical and an aspherical lens like this?
> 
> ...


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## mudman cj (Jun 15, 2008)

Would the KD lens work perfectly as I specified with the bezel loosened, tightened, or somewhere in between? I figured it would be capable of producing a tight spot due to the focal length, but I wondered how much adjustment would be possible in the beam angle using the bezel. Can you provide actual beam measurements from which to calculate the beam angle? 
Thanks again, 
C.J.


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## Fulgeo (Jun 16, 2008)

Using the KD lens with a Cree Q5 emitter I get a "square" point of light with the head backed out. As I "tighten" the bezel down the spot starts opening up for the desired effect I think you are describing in your previous posts. The KD lens fits the Mag head perfectly. KD gives you a rubber o-ring with his lens. I will have to take some measurements for you and get them back to you. One thing thou, I think the type or design of the emitter bezel effects how they preform with the lens in front of it. Just a thought. I am still waiting on some heat sinks to try a P7 emitter with the KD lens.


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## Fulgeo (Jun 22, 2008)

Mudman,

I have been testing my 2D Mag mod which has a Cree Q5 emitter, no reflector and the Kaidomain aspherical lens. Also note that my emitter sits about 6mm above the top of the 2D Mag body when you look at it without the flashlight head on. This is important because I have noted that if you seat the emitter lower you get different results. Now with about 6mm above the top placement I am able to get about a 4' circle of light at 20' distance. I am able to get a 8.5' or so circle of light at 40'. I like the 6mm emitter placement because I am still able to get the "square box" spot throw effect that I find very desirable. I am also able to get this spot effect with a reasonably tight and secure flashlight head. Note that if you seat the emitter higher you will give up your throw for more spot. This is doable depending on your heatsink. PM sent on the other information. Happy Mods!


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## mudman cj (Jun 22, 2008)

Hi Fulgeo,

I assume from your description that you get the 4' circle at 20' with the head tightened all the way down so as to bring the lens as close to the LED as possible, right? If so, then this lens could work for me provided that I could raise the LED higher than it is now. I think I would want it even higher than you have yours. I have to think of a good way to do that with the O-sink I am using. Perhaps a spacer could be used around the heat sink to keep the lip of the heatsink from resting down against the light body (O-ring?). Right now the tip of the LED dome sits about 3mm above the top of the body with the head removed. Also please report back with your evaluation of the other lens you have coming. I am still on the lookout for a lens with about a 50mm focal length though...


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## Fulgeo (Jun 23, 2008)

Correct, the head was tightened all the way down. Please note that I am using a Cree Q5 emitter. You mentioned you are using Lux III. I do not know how the emitter dome of a Cree differs from the Lux and I am pretty sure it makes a difference especially in the context of what we are talking about.




mudman cj said:


> Hi Fulgeo,
> 
> I assume from your description that you get the 4' circle at 20' with the head tightened all the way down so as to bring the lens as close to the LED as possible, right? If so, then this lens could work for me provided that I could raise the LED higher than it is now. I think I would want it even higher than you have yours. I have to think of a good way to do that with the O-sink I am using. Perhaps a spacer could be used around the heat sink to keep the lip of the heatsink from resting down against the light body (O-ring?). Right now the tip of the LED dome sits about 3mm above the top of the body with the head removed. Also please report back with your evaluation of the other lens you have coming. I am still on the lookout for a lens with about a 50mm focal length though...


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## Fulgeo (Jul 2, 2008)

Hey guyz,

I have put together a SSC P7 mod and have been evaluating my stock of lenses with it. With a focal length of 34mm Kadomain's aspherical lens does give you that perfect square box projection, but now you get four of them together. Sort of a cross-hair effect with a big black "+" in the center of the beam. This is a caused by the dead space between the 4 emitters that make up the P7. I found this undesirable in a flashlight. I did get very good results thou by using SurplusShed 250mm - 300mm aspherical lenses. It cleans up the beam and removes artifacts just like in a "fat" filament incandescent mod. If you have a P7 mod give it a try you might like it.


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## mudman cj (Jul 20, 2008)

I have been working with this lens that was found and tried first by Fulgeo. It works well to achieve the effect I was after, and is a great deal at $4.99 shipped, but it does have one issue that requires a solution. It fits down inside the slightly larger ID right at the opening of the light and therefore is loose when the bezel is tightened. It is possible to place the original lens behind the aspheric lens to make a better fit, but I ended up finding an O-ring that worked OK to do the job. I placed the O-ring on top of the lens so that it is between the bezel and lens just like stock. It is not what I would call a perfect fit, but I believe the light is every bit as moisture resistant as before; and this way I don't wonder how much output I am losing due to adding in the stock lens. The O-ring I am using is a 60 duro, butyl rubber, size 1-225 (1/8" cross section, 1 7/8" ID, 2 1/8" OD. I have one more if somebody wants it.

Thanks to Fulgeo for his suggestions and to everyone for tolerating my somewhat OT application for these lenses.


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## uluapoundr (Jul 21, 2008)

Fulgeo said:


> Hey guyz,
> 
> I have put together a SSC P7 mod and have been evaluating my stock of lenses with it. With a focal length of 34mm Kadomain's aspherical lens does give you that perfect square box projection, but now you get four of them together. Sort of a cross-hair effect with a big black "+" in the center of the beam. This is a caused by the dead space between the 4 emitters that make up the P7. I found this undesirable in a flashlight. I did get very good results thou by using SurplusShed 250mm - 300mm aspherical lenses. It cleans up the beam and removes artifacts just like in a "fat" filament incandescent mod. If you have a P7 mod give it a try you might like it.


 
I got a 250mm focal length lense from Surplus Shed (PL1103) for my P7 modded lights. The hotspot is cleaned up and brighter. 

Fulgeo, how does going from 250 to 300 change the beam pattern? Thanks for sharing.


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## Fulgeo (Jul 22, 2008)

Uluapoundr,

I got a chance to check out a FL 308mm and FL 500mm lenses on my P7 mod last night. They both worked as in they cleaned up the beam pattern and the greater the focal length the tighter the image it threw. Did not notice a big change going from 250 to 308. The properties of the P7 is a bit different than an incandescent but similar. I have a suspicion that the less glass the photons have to go thru the better, especially with LED mods. It might be better to have a 250-300mm focal length positive meniscus lens than a 250-300mm PCX lens.

Mudman,

Wanted to mention I did the same thing to tighten up my DX lens. I used another flat glass lens plus the DX lens to hold it tight initially. Since then I have found that a cut down stock plastic reflector plus the DX lens fit tightly together in the head. I think the "slop" that was present was because I made the mod without the reflector since it really did not need it.

P.S. As another thread mentioned it is desirable to frost the stock plastic with a few spattered coats of clear enamel paint. This in effect changes the stock reflector into a MOP. 



uluapoundr said:


> I got a 250mm focal length lense from Surplus Shed (PL1103) for my P7 modded lights. The hotspot is cleaned up and brighter.
> 
> Fulgeo, how does going from 250 to 300 change the beam pattern? Thanks for sharing.


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