# 3-21 Update Home Made Pseudo Integrating Sphere - photos and readings!



## run4jc (Feb 28, 2010)

*6-27 Update Home Made Pseudo Integrating Sphere - photos and readings!*

**UPDATED CHART - NEW READINGS**

Sometimes you just have to see for yourself, you know? Before you read this, please understand this disclaimer – I make no claims that the readings from the home made, uber cheap ‘pseudo integrating sphere’ are accurate! This was put together for my own edification and to satisfy curiosity, but it worked pretty well so I thought I’d share the results.

Paid $130 for the meter - $40 for the smooth foam ball (shipped), about $4 for the PVC pipe and $6 for a roll of black duct tape (which I still have most of). So for a total expenditure of about $180 I have a handy dandy 'poor man's' integrating sphere.

Test measurements are at the end of the post, but I thought I’d show you the construction. Inspiration came from a great thread over here, so I take NO credit for the idea of how to construct this – precisionworks and others provided the inspiration and the ideas.

Most of the photos are labeled.

































































































And here are the measurements. Pretty darn close – again, I make no claims for accuracy – this was just a fun project for me. Just fyi, the lux rating is what my meter shows – I divided each reading by 36 to estimate the lumens rating. I read that somewhere in the forum, although I can’t remember where.





This is the Spy 007 before (left side) and after (right side) DaFABRICATA XPG Neutral emitter swap





And here's my newest chart including some oldies and a few new lights. As my collection evolves, I try to keep this updated.




Hope this is of use or interest to someone!


Please PM or post if you have any questions...


lovecpf


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## KDOG3 (Feb 28, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*

Sweet!


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## scout24 (Feb 28, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*

Great work! interesting to see how the LS27 did... I would be curious to see how an LS20 would do in the same sphere.


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## DimeRazorback (Feb 28, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*

Great work Dan!

:twothumbs :bow:


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## rayman (Feb 28, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*

Great idea :twothumbs. Wish I had such a luxmeter.

rayman


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## Flying Turtle (Feb 28, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*

Nice job. Nothing better than a do it yourselfer.

Geoff


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## kramer5150 (Feb 28, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*

Nice work!!!

Love how you guys are keeping the manufacturers honest, its like putting them on a polygraph.

An oversized one size fits all opening for the light inlet won't work though. It will throw off your conversion factor when measuring lights of differing bezel diameters. In bigchelis' sphere we trace the light bezel onto white paper and cut a hole out so it fits snug around the light. The paper gets lightly taped over the light inlet on the sphere, so its a snug fit.

BC and MrG can elaborate on the technical aspects better than I can.

:thumbsup:


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## run4jc (Mar 1, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*



kramer5150 said:


> Nice work!!!
> 
> Love how you guys are keeping the manufacturers honest, its like putting them on a polygraph.
> 
> ...



Thanks! I read a lot of MrGman's writings within the post I mentioned, originated by precisionworks back in 2008. As mentioned in the thread, there's no way this sphere can be deemed as 'accurate' - BUT, it would be fairly easy to do as you say and snug up the fit for each light.

I briefly considered using a 3 inch inlet instead of a 2 inch so large bezel lights would fit, but decided against it because I have only 1 such light (a Jetbeam M1X) and I feared that there would be too much 'leakage' with all the other lights I own.

Thanks for the tip!

Dan


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## run4jc (Mar 1, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*



scout24 said:


> Great work! interesting to see how the LS27 did... I would be curious to see how an LS20 would do in the same sphere.



Thanks! Of course, my LS20 went away...:mecry:but I'm not going to suggest anyone send one of those!


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## csshih (Mar 1, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*

do you have any UV lights to test?
from my experience, the extech meters do not have a photopic curve response filter, the ea31 datasheet makes no mention of one either.


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## run4jc (Mar 1, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*



csshih said:


> do you have any UV lights to test?
> from my experience, the extech meters do not have a photopic curve response filter, the ea31 datasheet makes no mention of one either.


 
No sir - no UV lights...


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## BigHonu (Mar 1, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*

Outstanding!


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## sfca (Mar 1, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*

Is that Milky E1B the same as an E2DL creemator? Readings, please!:huh:


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## run4jc (Mar 1, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*



sfca said:


> Is that Milky E1B the same as an E2DL creemator? Readings, please!:huh:



Not quite - and the readings are there. It's kind of confusing - you have to look on the next line because it is listed as "Milky ME1B Creemator/McGizmo 2x123 McClicky" - the reading is beside the line showing McGizmo 2x123 McClicky. To save you a bit of time, the E2DL read 215 lumens on high and the ME1B read 248...

I found this particularly interesting since my E2DL is one of the OLDER ones before they 'updated' the rating to 200. So 2 things are certain - Surefire is very conservative with their ratings, and Milky can indeed 'milk' the max from an emitter! Hope that helps - 

Dan


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## sfca (Mar 1, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*



run4jc said:


> the E2DL read 215 lumens on high and the ME1B read 248...



Ah! I see.

It's nice to see more figures from the mod, I saw the beamshots here vs. a standard E2DL (second row on left) and I wanted that!!

When I had my E2DL before I didn't like the fact it was a concentrated circle in the darkness, but with that milky mod it'd look alright. 
Slightly bigger hotspot, more lumens, higher lux.

It looks like it's *burning a hole in the ground *:laughing: LOL!!


P.S. It's kinda odd to see the Nailbender making 300+ lumens (I see that was a /36 calculation) but so much more lux. The lumen number here is less then the >500 numbers elsewhere;
_However _the lux numbers are closer here [11,500 lux] then I saw in Bigchelis P60 thread. That was only 4,200 lux. Compared with an E2DL (~8,500 lux), Quark Turbo (>E2DL) the SST-50 _definitely _has more lux.


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## run4jc (Mar 1, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*



sfca said:


> Ah! I see.
> 
> It's nice to see more figures from the mod, I saw the beamshots here vs. a standard E2DL (second row on left) and I wanted that!!
> 
> ...



Yes - on the Nailbender, I have feeling it is the massive flood the light puts out. I took all the steps I could think of to tame any of those beasts, but still, it is a bright monster!

As for the Milky, as you probably know, Scott sets them up so you can focus the spot - you can have more spill or go to the max throw. I usually keep mine on a 'blend...'

Anyway, it's all fun and I appreciate all the comments! The construction of the IS was such that mods can easily be made.

Thank you!


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## csshih (Mar 1, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*



run4jc said:


> No sir - no UV lights...



ah, oh well. It should still be reasonably accurate as long as you're not testing incandescent lights also! :twothumbs


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## sfca (Mar 1, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*



run4jc said:


> As for the Milky, as you probably know, Scott sets them up so you can focus the spot - you can have more spill or go to the max throw. I usually keep mine on a 'blend...'



Can I ask hows yours compared to the beamshot link. How would you say that Creemator shot is set up as?


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## kramer5150 (Mar 1, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*



csshih said:


> ah, oh well. It should still be reasonably accurate as long as you're not testing incandescent lights also! :twothumbs



Curious.... are foot candle meters even capable of (accurately) measuring wavelengths to the far extremes of the visible spectrum? I know (for example) that red colors are hard for many to detect.

???


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## run4jc (Mar 1, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*



sfca said:


> Can I ask hows yours compared to the beamshot link. How would you say that Creemator shot is set up as?



It looks like it is set for spot - but it depends on the camera. What I mean is that the 'flood' from the Creemator (at least on mine) is a definite 'step' - or a definite defined transition from spot to flood. If the camera were set up to reduce the exposure it might make it hard to see the spill. BUT, my guess is that it is set for max throw/spot. I know that with mine, when I focus it for max throw it's like an LX2/E2DL on steroids.



kramer5150 said:


> Curious.... are foot candle meters even capable of (accurately) measuring wavelengths to the far extremes of the visible spectrum? I know (for example) that red colors are hard for many to detect.
> 
> ???


 Oh, man - you are way over my head technically. While I understand what you are talking about, I have no clue of the range of the light spectrum that light meters such as mine can detect. Sorry!


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## sfca (Mar 1, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*



run4jc said:


> It looks like it is set for spot - but it depends on the camera. What I mean is that the 'flood' from the Creemator (at least on mine) is a definite 'step' - or a definite defined transition from spot to flood. If the camera were set up to reduce the exposure it might make it hard to see the spill. BUT, my guess is that it is set for max throw/spot. I know that with mine, when I focus it for max throw it's like an LX2/E2DL on steroids.



For the reading is it set on 'blend'? I'm hypothesizing on max throw the reading would be higher, but who knows.

Since I sold my beloved E2DL:mecry:it will be some time before I get a chance to have my own Creemator w/ 2-way clip.
Seeing as the new T20C2 R5 will have a similar sized hotspot and greater lux this would then be a (much cheaper) alternative. 
It's bigger




, and sticks out too much for pocket-carry



, but whatever.


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## angelofwar (Mar 1, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*

Nice Job...I wouldn't mind doing something like this! Nothing like a sense of accomplishment when you build somethnig yourself, or "finally get it right"! Nice Job!


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## mdocod (Mar 1, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*

Beautiful project and more than accurate enough for comparing one source to another IMO. I really love seeing the precise results from a true IS like MrGman has been using, but in reality, +/- say, 7% or so is more than accurate enough for the purpose of comparing portable light sources, especially considering that the eyes can't see that differences anyways. 

I've been thinking about something from PVC parts or other plastics to make a cheap IS.

Eric


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## SFfanman (Mar 2, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*

Great Job Dan! Everything from the pictures to the layout of readings is very impressive. A lot of info that will benefit a lot of people (including me). I have to ask though, 

Do you get some nostalgic feeling having an original Haiku back in your hands? :devil:


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## run4jc (Mar 2, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*



sfca said:


> For the reading is it set on 'blend'? I'm hypothesizing on max throw the reading would be higher, but who knows.


 Yes, I believe it was set with the bezel tightened down all the way...i.e., 'blend.' However, since it is so easy to take readings, later today I'll read it set for max spot and post the findings. I've also been wanting to test the M1X anyway, but the readings will surely be off because the darn thing won't fit into the 2 inch tube. I'll just shine it through as best I can and see what we come up with!



sfca said:


> Since I sold my beloved E2DL:mecry:it will be some time before I get a chance to have my own Creemator w/ 2-way clip.
> Seeing as the new T20C2 R5 will have a similar sized hotspot and greater lux this would then be a (much cheaper) alternative.
> It's bigger
> 
> ...


Following a wave of McGizmo purchases, i was doing some major liquidating - even my much cherished Surefires. LX2 went away, C2 went away....but I couldn't sell the E2DL! The form and function of it make it one of my all time favorites! Then after reading the output, it seems like it was the right decision. Just wish I had taken LX2 readings before it "left the building", but based upon this test I assuming it would have read about 25-30% higher...



angelofwar said:


> Nice Job...I wouldn't mind doing something like this! Nothing like a sense of accomplishment when you build somethnig yourself, or "finally get it right"! Nice Job!


 It is really easy - and relatively cheap. I just had to remember not to take it TOO seriously...after all, a REAL integrating sphere costs $$$$$. But considering the results, it was very rewarding considering the small amount of $ involved and the short construction time. If you are interested, the sphere was purchased HERE and the the meter HERE. Everything else came from Home Depot - an alternative idea is a round novelty cooler sold at WalMart - but I like the foam. It's easy to work with.



mdocod said:


> Beautiful project and more than accurate enough for comparing one source to another IMO. I really love seeing the precise results from a true IS like MrGman has been using, but in reality, +/- say, 7% or so is more than accurate enough for the purpose of comparing portable light sources, especially considering that the eyes can't see that differences anyways.
> 
> I've been thinking about something from PVC parts or other plastics to make a cheap IS.
> 
> Eric


 Thanks! Please see the last quote and you can see where everything was purchased. As you could see, PVC parts played a big role in mine. I wish more people would build one - perhaps everyone's experiences would bring about many improvements.



SFfanman said:


> Great Job Dan! Everything from the pictures to the layout of readings is very impressive. A lot of info that will benefit a lot of people (including me). I have to ask though,
> 
> Do you get some nostalgic feeling having an original Haiku back in your hands? :devil:


 You'd better know it! And who knows....but the budget is definitely in a mode of REST for some time to come...unless a deal I can't refuse pops up on the B/S/T...:naughty:


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## run4jc (Mar 2, 2010)

*Re: **UPDATED**Home Made Pseudo Integrating Sphere - photos and readings!*

**updated chart in first post**

One of my many failings (now in my 50s it seems there are more and more!) is that hobbies quickly become obsessions. Such is the case with flashaholism. But there could be worse things, right?

So with all the questions that have been posted I decided to do a few updates. Regarding the Creemator, here are 3 photos followed by a photo of a stock, older Surefire E2DL. Photos are totally unretouched - activated the shutter by remote control. The light was mounted in a mic holder - it may have moved slightly when I adjusted the bezel then when I changed to the E2DL. Photos are labeled...




















There's more flood than you can see, but perhaps when there's complete darkness I'll use a longer exposure so you can see the spill. This still gives you a good image of how the beams are different.

Here's a photo of the sphere with a light in it. As you can see, there is a small amount of light 'leakage' - hard to believe since this is 1 inch thick foam. What was interesting to me (and you can't see it in the photo) was the light emanating from the port...pure white, no spot, totally 'even' to the naked eye - and hopefully that's exactly what the sensor 'sees.'





What else was interesting is the commentary on the regulation. After turn on the M1X drops like a rock. 10% in 30 seconds! The Surefire E2DL holds steady on low, but drops on high. Creemator suffers from some drop off, too. No biggie - hard to notice with the naked eye, but I was tempted to video the meter in the first 30 seconds just to show it. Maybe another day.

The Jetbeam reading has to be off - the light was pressed up against the edge of the port, but there's a few inches of tube that it had to shine through - I know that threw it off. Still impressive.

The little Quark Ti MiNi 123 is amazing - it was over 200 lumens (again, I know this isn't accurate - but it is all relative.)

At the end of the day, what continues to be interesting to me is the difference in batteries and regulation. FAR MORE SCIENTIFIC info is available throughout the forum - cool run time graphs and so forth - but with the meter you can at least watch for the regulation. McGizmos hold like a rock - at least for the minute or so the lights are on - haven't done continuous run longer than that. The Nitecore and Quark lights do a good job, too. The Surefire L1 did well - the E2DL did well on low but suffered from dropoff on high. Same with the Creemator.

Too much fun...hmm - can you make a living doing this? :thinking:



lovecpf


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## angelofwar (Mar 2, 2010)

*Re: **UPDATED**Home Made Pseudo Integrating Sphere - photos and readings!*

Hmmm...what if you painted the inside of the foam with a few coats of black paint (dull finish, somethnig like rustoleum)...that might stop the "leakage"???


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## run4jc (Mar 2, 2010)

*Re: **UPDATED**Home Made Pseudo Integrating Sphere - photos and readings!*



angelofwar said:


> Hmmm...what if you painted the inside of the foam with a few coats of black paint (dull finish, somethnig like rustoleum)...that might stop the "leakage"???



I had thought of that, only my thought was to paint the _outside_...I could be wrong, but shouldn't the inside be white to ensure maximum light reflection?

Great idea, though - and one that will most likely happen...and perhaps I could paint the _inside_ with a flat, matte white?


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## Saint_Dogbert (Mar 2, 2010)

*Re: **UPDATED**Home Made Pseudo Integrating Sphere - photos and readings!*

Actually, you wouldn't want to paint black on the outside _or_ inside, because black absorbs light. There wouldn't be any difference between the light escaping from the foam ball in to the surroundings and having it absorbed by the black paint. As far as I understand this IS stuff, you have the right idea - get a very flat, very white paint onto the inside surface for maximum diffusion of the beam. I was thinking if you first put on a coat of silver paint before the white, that would achieve even better results.



Cool project, thanks for sharing!


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## run4jc (Mar 2, 2010)

*Re: **UPDATED**Home Made Pseudo Integrating Sphere - photos and readings!*



Saint_Dogbert said:


> Actually, you wouldn't want to paint black on the outside _or_ inside, because black absorbs light. There wouldn't be any difference between the light escaping from the foam ball in to the surroundings and having it absorbed by the black paint. As far as I understand this IS stuff, you have the right idea - get a very flat, very white paint onto the inside surface for maximum diffusion of the beam. I was thinking if you first put on a coat of silver paint before the white, that would achieve even better results.
> 
> 
> 
> Cool project, thanks for sharing!


 GREAT input - thank you. Maybe a silver primer followed by a couple of coats of flat bright white? Don't know where my head was with painting the outside black - by then the light has already been 'absorbed' into the foam.

Here I go again - my intent was to not take this too seriously! But what the heck - this improvement would be very easy! :thumbsup:


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## kramer5150 (Mar 2, 2010)

*Re: **UPDATED**Home Made Pseudo Integrating Sphere - photos and readings!*



Saint_Dogbert said:


> Actually, you wouldn't want to paint black on the outside _or_ inside, because black absorbs light. There wouldn't be any difference between the light escaping from the foam ball in to the surroundings and having it absorbed by the black paint. As far as I understand this IS stuff, you have the right idea - get a very flat, very white paint onto the inside surface for maximum diffusion of the beam. I was thinking if you first put on a coat of silver paint before the white, that would achieve even better results.
> 
> 
> 
> Cool project, thanks for sharing!



It does not need to be painted, so long as your conversion factor is calibrated to the unpainted styrafoam. Painting it to block light will allow you to use it in a brighter lit room however. But as long as you use it in a dim room, it should be fine unpainted. If you paint it to entrap light, you might have have to recalibrate it.

FWIW Neither MrG or BCs spheres are painted, but using them near a bright big-screen TV or lamp will throw off the readings.

I think just placing the sphere in an enclosed box would be sufficient. IIRC MrGs sphere is in a cardboard box.


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## Saint_Dogbert (Mar 2, 2010)

*Re: **UPDATED**Home Made Pseudo Integrating Sphere - photos and readings!*



kramer5150 said:


> It does not need to be painted, so long as your conversion factor is calibrated to the unpainted styrafoam.



My limited understanding of the principle behind an integrating sphere is that achieving the maximum diffusion of light within the sphere is the goal. If there are still some specular highlights, then the beam may glare into the sensor; or differences in beam shapes would have a greater effect, and calibration wouldn't be able to compensate. Therefore, it would seems like adding flat white paint would improve accuracy - correct me if I'm wrong. I get that there isn't a need to paint to sphere to protect against the ingress of ambient light, as that is easily solved by turning out said lights or covering the thing up with a blanket. That would also be the point of adding silver paint, and it would be as likely to show through the white, darkening it, and mess things up more than it helped.


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## sfca (Mar 2, 2010)

*Re: **UPDATED**Home Made Pseudo Integrating Sphere - photos and readings!*

Hmm.. The max spot looks like max flood, and vice versa. Actually the bezel tightened looks like max flood, and the other 2 progressing into spot.

The E2DL beam looks like a medium between the picture that look floodiest and the picture that looks like a flood/spot blend. 
Not necessarily the way they are labeled, but the Creemator looks mean nonetheless!


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## run4jc (Mar 3, 2010)

*Re: **UPDATED**Home Made Pseudo Integrating Sphere - photos and readings!*



kramer5150 said:


> It does not need to be painted, so long as your conversion factor is calibrated to the unpainted styrafoam. Painting it to block light will allow you to use it in a brighter lit room however. But as long as you use it in a dim room, it should be fine unpainted. If you paint it to entrap light, you might have have to recalibrate it.
> 
> FWIW Neither MrG or BCs spheres are painted, but using them near a bright big-screen TV or lamp will throw off the readings.
> 
> I think just placing the sphere in an enclosed box would be sufficient. IIRC MrGs sphere is in a cardboard box.



The sphere is always in a dimly lit or dark room, in the box with a dark blanket draped over it...the meter reads .1 lux (that's point 1) - which is basically no light inside the sphere.



Saint_Dogbert said:


> My limited understanding of the principle behind an integrating sphere is that achieving the maximum diffusion of light within the sphere is the goal. If there are still some specular highlights, then the beam may glare into the sensor; or differences in beam shapes would have a greater effect, and calibration wouldn't be able to compensate. Therefore, it would seems like adding flat white paint would improve accuracy - correct me if I'm wrong. I get that there isn't a need to paint to sphere to protect against the ingress of ambient light, as that is easily solved by turning out said lights or covering the thing up with a blanket. That would also be the point of adding silver paint, and it would be as likely to show through the white, darkening it, and mess things up more than it helped.



The only reason I was concerned about the 'leaking' light was MrG's post over here...that said, it looks kinda cool in a dark room with some of the light leaking out - eerie! :laughing: Of course, I have to remove the blanket to see it...



sfca said:


> Hmm.. The max spot looks like max flood, and vice versa. Actually the bezel tightened looks like max flood, and the other 2 progressing into spot.
> 
> The E2DL beam looks like a medium between the picture that look floodiest and the picture that looks like a flood/spot blend.
> Not necessarily the way they are labeled, but the Creemator looks mean nonetheless!



I understand - it's hard to capture in a photo. The E2DL was on high with fresh Surefire 123s...with the Creemator, when you tighten down all the way you get an increase in the spill immediately around the spot - the spot diminishes only slightly. It's logical - when you tighten the bezel down you have effectively 'moved the LED forward', thus creating more flood and reducing the effect of the TIR optics in the E1B head. When it is maximized for spot, you've basically repositioned everything to the way it came from the factory. As you loosen the bezel, the LED is becoming more recessed and the beam is less focused. It looks as if you are getting a more pronounced flood and a bigger spot (actually you are) but the overall brightness of the spot is decreasing - hard for the camera to catch that. It's the transition from spot to, eventually when you remove the bezel completely, flood. I think it is important to note that the overall circumference of the lighted area doesn't change in size - just the intensity of the light within each "segment" of it. 

It's a very elegant and effective way to make the light into a multi-tasker. Hat's off to Milky! :twothumbs Here's some fresh photos that hopefully show the differences a bit more effectively...


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## tolkaze (Mar 7, 2010)

*Re: **UPDATED**Home Made Pseudo Integrating Sphere - photos and readings!*

Wow, cheap, fairly easy, and at least some good looking numbers coming out of it. in regards to the port, and light leakage, could you get a piece of sheet latex, or another stretchy rubber, cut a much smaller hole than you need and stretch the rubber over the bezel of the light?


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## run4jc (Mar 8, 2010)

*Re: **UPDATED**Home Made Pseudo Integrating Sphere - photos and readings!*



tolkaze said:


> Wow, cheap, fairly easy, and at least some good looking numbers coming out of it. in regards to the port, and light leakage, could you get a piece of sheet latex, or another stretchy rubber, cut a much smaller hole than you need and stretch the rubber over the bezel of the light?



Great idea - thanks. I'll try that. Interestingly, the last time I took measurements, just for grins I tried to cover the hole as best I could with my hand - granted, it was at the back of the tube where it would make the least difference, but it did change the readings ever so slightly - by a lux or 2 - which is no change in lumens basically. BUT, a change at the point where the light is inside the sphere might just make a significant difference. We'll see! Thanks again! :thumbsup:


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## run4jc (Mar 9, 2010)

*Re: **UPDATED**Home Made Pseudo Integrating Sphere - photos and readings!*

UPDATE - chart in first post has been updated to include:

Milkyspit KL4 Boxter (acquired from another member)

Sundrop XR-U hosting a Sandwich Shopped GDuP engine fitted with Seoul High CRI emitter

Lego project - Erin A19 host/Sandwich Shoppe GDuP Cree XR-E engine/McClicky 2x123 body

Thanks!


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## csshih (Mar 9, 2010)

*Re: Home Made Pseudo Integrating Sphere - photos and readings!*



kramer5150 said:


> Curious.... are foot candle meters even capable of (accurately) measuring wavelengths to the far extremes of the visible spectrum? I know (for example) that red colors are hard for many to detect.



sorry, I forgot to check this thread. I will try to see how sensitive the meter is to 940nm IR light, then 365nm(peak) UV light. will update later tonight unless I forget.


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## run4jc (May 15, 2010)

Updated readings in the original post...


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## Vortus (May 15, 2010)

Not sure if it would help, but it might. Consider covering the holes with a piece of white vinyl, available from most fabric stores. Cut a slit that the lights can go through, or fit it over the light like the splash block on most gas pumps.


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## run4jc (Jun 28, 2010)

*6-28 Update Home Made Pseudo Integrating Sphere - photos and readings!*

Readings updated 6/27 - interesting how some have changed.

:wave:

lovecpf


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## candle lamp (Sep 24, 2011)

*Re: 6-28 Update Home Made Pseudo Integrating Sphere - photos and readings!*

Very well done and very informative thread. run4jc! :thumbsup:
Thanks for your sharing the information.
You say lumen is an estimation lux reading divided by 36.

I'd like to know how to get the value "36"?


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## run4jc (Sep 25, 2011)

*Re: 6-28 Update Home Made Pseudo Integrating Sphere - photos and readings!*



candle lamp said:


> Very well done and very informative thread. run4jc! :thumbsup:
> Thanks for your sharing the information.
> You say lumen is an estimation lux reading divided by 36.
> 
> I'd like to know how to get the value "36"?


Thank you candle lamp! Funny, the value is now 7 because of some changes I made to the sphere. There are MANY here who are far more knowledgeable about such things, but for my amateur sphere it is simple - I have one light that I consider the 'control' light - my McGizmo Haiku XPG. It is rock solid in brightness and regulation, and measures 190 lumen consistently (which doesn't match Don's stated output, I know) - and I cross referenced it with a couple of other well-known lights that BigChelis and Mr.Gman measured - mine measured very close to their readings.

So, I take the output (shown on the meter) when I measure the Haiku and divide that by 190 - that gives me the divisor (as previously stated, now 7 since I made some enhancements to the sphere). Thus, that is the divisor I use when measuring other lights. For example, my Zebralight SC600 reads 5,170 lux from the meter - divide by 7 and you get lumen rating of 738, which is close to the out the front rating from Zebralight. I find that the majority of my lights read close to the rated specs based on this method.

Please understand, before anyone jumps in and explains why this is all wrong , this was done for my own enjoyment and education and I make NO claims that the readings are accurate! This sphere cost less than $200 to build, and a 'real' integrating sphere runs in the $thousands, right? But what I do maintain is that the 'relative' readings are useful. If I read 3 different lights, the measurements of relative differences should be somewhat accurate.

Long answer to a simple question, but hopefully I've explained my thought processes. It's a fun project!


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## candle lamp (Sep 25, 2011)

*Re: 6-28 Update Home Made Pseudo Integrating Sphere - photos and readings!*



run4jc said:


> Thank you candle lamp! Funny, the value is now 7 because of some changes I made to the sphere. There are MANY here who are far more knowledgeable about such things, but for my amateur sphere it is simple - I have one light that I consider the 'control' light - my McGizmo Haiku XPG. It is rock solid in brightness and regulation, and measures 190 lumen consistently (which doesn't match Don's stated output, I know) - and I cross referenced it with a couple of other well-known lights that BigChelis and Mr.Gman measured - mine measured very close to their readings.
> 
> So, I take the output (shown on the meter) when I measure the Haiku and divide that by 190 - that gives me the divisor (as previously stated, now 7 since I made some enhancements to the sphere). Thus, that is the divisor I use when measuring other lights. For example, my Zebralight SC600 reads 5,170 lux from the meter - divide by 7 and you get lumen rating of 738, which is close to the out the front rating from Zebralight. I find that the majority of my lights read close to the rated specs based on this method.
> 
> ...


 
Many thanks for your kind reply. 
I'm very interested in the integrating sphere and just thought I can get the lumen rating by using it. However I have realized it's not easy not only to make the integrating sphere
but also to get the proper(correct) lumen values. There are many informative & good threads relating to the integrating sphere here in CPF I've found so far. 
I have a plan to make the integrating sphere, but need much time & money & ETC(light meter). There is no 10~16 inch smooth foam sphere here in Korea. :shakehead
Maybe I need to get it from other country. 

Do you think I need a light meter real time data logger measurement range to 400,000 lux? Or 100,000 lux is sufficient to me? Because new multi XM-L lights are released nowadays 
and much brighter lights will be introduced in the future, I think. 

Thanks in advance and best regards,
KyeongHo


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## run4jc (Sep 25, 2011)

*Re: 6-28 Update Home Made Pseudo Integrating Sphere - photos and readings!*



candle lamp said:


> Many thanks for your kind reply.
> I'm very interested in the integrating sphere and just thought I can get the lumen rating by using it. However I have realized it's not easy not only to make the integrating sphere
> but also to get the proper(correct) lumen values. There are many informative & good threads relating to the integrating sphere here in CPF I've found so far.
> I have a plan to make the integrating sphere, but need much time & money & ETC(light meter). There is no 10~16 inch smooth foam sphere here in Korea. :shakehead
> ...


 
If you look back in my threads you will find links to where I purchased the foam sphere - I don't know if they ship internationally, but maybe. The box is quite large so shipping could be costly. Some have used items such as styrofoam coolers, etc...they may or may not be as effective, but would likely be easier to obtain. As for the meter, your comments are insightful. Still, with mine reading as high as 20,000 lux, that gives me the ability to read up to around 2800 lumen - the only light I've ever had access to that exceeded that was VanIsleDSM's Septa. Still, a lot will depend on your sphere and divisor.

Good luck!


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## candle lamp (Oct 4, 2011)

*Re: 6-28 Update Home Made Pseudo Integrating Sphere - photos and readings!*

Thanks for your interest & good word. run4jc! 

I got a smooth foam box(40x30x30cm, 3cm thickness) and found there is considerable light leakage from the box without painting inside.
(But I heard painting makes the foam box melt.) 
So I'd like to make the wooden box(50x50x50cm, 1.5cm thickness) to prevent leakage of light.
If you don't mind, I would like your advice on the size of the light box, painting, ETC. that I should consider.

Best regards,
KH


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## run4jc (Oct 4, 2011)

candle lamp said:


> Thanks for your interest & good word. run4jc!
> 
> I got a smooth foam box(40x30x30cm, 3cm thickness) and found there is considerable light leakage from the box without painting inside.
> (But I heard painting makes the foam box melt.)
> ...


 
I had the same issue and tried painting but was not happy with the result. As someone else posted, I don't believe the leakage will be a big problem as long as you calibrate. My sphere isn't painted and it sits in the same cardboard box that it was shipped in. Good luck!!


Sent from my iPad using Tapatalk


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## DenBarrettSAR (Feb 22, 2013)

I found several of the Lux Meters on Ebay for prices ranging between 35 to 60 bucks. I wonder if they are worth the try for a DIY Lumen measuring sphere like yours ?


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## run4jc (Feb 23, 2013)

DenBarrettSAR said:


> I found several of the Lux Meters on Ebay for prices ranging between 35 to 60 bucks. I wonder if they are worth the try for a DIY Lumen measuring sphere like yours ?



They ought to be okay. My opinion is not scientific - only opinion - but it seems to me that the most important thing is finding a "control" light to correlate the reading of the meter to the output of your light. For example, my McGizmo Haiku is virtually guaranteed to produce 189 lumen (OTF.) But my meter measures in foot candles and lux. So when I measure the Haiku, my meter reads 1330 lux. I divide that by 7 and , viola, you have 190 lumen. 

Although my claims that this sphere is not necessarily accurate have been constant, I will say that its readings have also been constant.  In the 3 years since I originally posted this, many lights have come and gone from my collection and the sphere has proven to be consistent - even with higher output lights such as a Malkoff Wildcat or Hound Dog XML2. 

It's also important to properly baffle the inside of the sphere so that no direct light hits the sensor. All you want to measure is the "ambient" light inside the sphere. So my feeling is that the meter is less important than the design and construction of the sphere.

And again, credit for the basic design goes back to precisionworks, MrGMan and Bigchelis...


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