HDS Systems #23

[desert.snake]

Does it affect the beam?

Definitely affects when viewed in a sphere, maybe if the scratches are very extensive, then just like dust, as Hogo mentioned, a little dust immediately reduces lumens by some % (I can not find this quote, but it was definitely here ). But this affects the shape of the beam very little, it can be seen on my SF and large lamp lights, which have a lot of scratches on the glass. If there are a very lot of scratches, then the beam will become more diffuse, as can be seen on car headlights

 

[Hogokansatsukan]

Not a little dust. A filthy lens. The kind of lens that, if it were a person, would need lots of penicillin. Pretty much all my HDS lights that get used. Can I tell the difference between a filthy lens and clean lens in use? Not at all. You would need a light meter or sphere to tell the difference.
Micro scratches will have NO effect on the beam. Most scratches will also occur in the center of the lens, which has the smallest impact. Most of the light leaving the end of the flashlight is from around the center, not the center itself, from a light with a reflector.

 

[Hogokansatsukan]

A note on sapphire. If any of you have, and I know some of you have, spoken with Henry about sapphire lenses, what he has told you is that they are simply for bragging rights. Does it make a difference in beam? No. Yes, they are harder to scratch, but scratches occur in the center of the lens because of the protective bezel. They make no impact on the beam. It is not a watch crystal that is exposed to and susceptible to getting all banged up. Watch crystals, yes sapphire is the way to go. On an HDS, it is just bragging rights.
Yes. My personal special metal lights will have sapphire lenses... only because of bragging rights. My users are all glass.
Why do we even offer sapphire lenses? Only because people want them.

 

[K2-bk-bl-rd]

The only problem is that with a anti-reflective coating on the outside, they DO scratch as easily as glass. It's just the coating making it look scratched, instead of the sapphire. Basically it is sapphire in name only, at that point.
I scratched my Sapphire lens HDS, trying to clean it.

 

[Beard Man]

I don't care about minor scratches, but an anti-reflective coating on the sapphire lens scratches VERY easily.
For $73 the coating should be better quality.
I still have no response from HDS (sent two emails).

 

[LRJ88]

I don't care about minor scratches, but an anti-reflective coating on the sapphire lens scratches VERY easily.
For $73 the coating should be better quality.
I still have no response from HDS (sent two emails).

The coating is good quality, the quality isn't what's in question here, the issue is that the coating is delicate and doesn't do well with any kind of touching. That's not just the coating here, it's pretty much all AR coating by the very nature of it.

 

[Hogokansatsukan]

From the FAQ:
What is an anti-reflective (AR) coating on the lens?

The purpose of a lens is to transmit as much light as possible. As the light passes though an untreated air/lens surface, roughly 5% of the available light is reflected back. This reflected light is wasted. A glass lens has two air/lens surfaces - one on each side of the lens and thus 10% of the light can be lost.
In addition to using ultraclear glass for our glass lenses, we apply an anti-reflective coating to both lens surfaces to reduce the amount of reflected light and thus increase the amount of light transmitted through the lens. Both surfaces are coated to maximize the amount of light the lens can transmit. This increases the efficiency of your flashlight and allows 97% of the light to be transmitted out the lens.
An anti-reflective coating is a vapor deposition coating that is applied in a vacuum. The coating is a fraction of a wavelength of light thick and acts like a tuned circuit in electronics to match the "impedance" between the lens and the air. This allows the lens to capture and transmit the light that would otherwise be reflected.
The anti-reflective coating is fairly durable but it is very thin. Excessive rubbing will abrade the coating on the exterior surface. Paper-based towels are very abrasive and should never be used to clean or wipe the lens. Flushing the lens under running fresh water and then blowing or shaking off any remaining water is best. However, even if you rub off the coating or it becomes soiled and stops working, you will only reduce the output by a small amount - which is not significant.

 

[kerneldrop]

This is why as soon as I get the light I put it through extreme use to shatter the lens into tiny particles so I don't have to worry about it anymore

 

[LRJ88]

After it getting dusty a few times and giving the lens a bit of the old finger dusting it hasn't changed squat, i'm pretty sure i'd need good equipment just to notice a difference in output when it's dusty as well.

 

[PoliceScannerMan]

 

[Beard Man]

Sorry, I didn't know that excessive rubbing (towel cleaning or any other material) will abrade the coating on the exterior surface.
I thought that the coating was quite durable and that it could withstand intensive rubbing.
I was wrong.

 

[Hogokansatsukan]

It's an easy mistake to make. Those anti-reflective coatings are incredibly thin and I know the first sapphire you had was defective as for some reason, the coating was not cured... I have that one in a box around here somewhere.
For my flashlights, I don't much care but I have some very expensive (eye watering expensive optics by Swarovski) that in the rare case they need to be cleaned, I first use compressed air to blow the chunks off, then use a very soft bristled brush to wipe it, then use a special lens cleaner with a microfiber cloth. I don't bother with my flashlights as within an hour of carry, they will be full of dust and fine desert grit.

 

[Robot Mania FU]

Finally something I can contribute to. First off, let me say I'm one of those people who are extremely careless with my gear (hence why I buy stuff I CAN be careless with.) I fish daily on the river and have beaten the hell out of these lights. Aside from that, I am constantly setting things down in the rocky/sandy beaches on the river (think the beach, but way coarser sand). Everything I own gets covered in sand and wiped off with the ole' trusty shirt.

It was MUCH harder than you think to even get this on camera, but as you can see, I've managed to scratch the glass lens on the left where I've only partially removed the AR coating on the sapphire on the right while the surface of the lens is relatively unscathed. Both lenses are in SIGNIFICANTLY better shape than some of my other lights I use, trust me...I had to seriously abuse these things to get to this point. If you are working in a highly abrasive environment, the only "benefit" of sapphire is just that...you will only destroy the AR coating and not the surface of the lens it's self.

With all of that being said....at the end of the day, turn the lights on and you couldn't tell the difference from a brand new beam to save your life.

 

[PoliceScannerMan]

Beautiful pic sir, love seeing users.

 

[muichimon]

The NB27 I ordered arrived today. It was a very nice incandescent warm color temperature. For the time being, I compared NB45 and NB27 side by side. In the daytime, the low color temperature is more emphasized, and it feels as if the setting sun is shining only here.

 

[John_Galt]

There will be no dedoming by us... unless I can convince Henry, but I doubt he will want to do that. What the end user chooses to do is up to them. I may try it on one just to compare on the sphere... a 5000k domed and dedomed side by side might be an interesting experiment with actual data from the integrating sphere. I'll have 3 built out to play with next month.

It would also be worth seeing the difference in the hotspot intensity, and you have the means to directly compare both original output and intensity before and after dedoming, with the same light, battery (or powersource, I suppose), reflector etc etc. I've been very happy with the resulting change in hotspot intensity with dedomed XP-G/G2's, and more recently the nichia 519. The samsung lh351 didnt really seem to make much more throw, by way of the mk.1 eyeball.

While Henry may not be interested in making LEP-esque all hotspot no flood pocket throwers, he at least recognizes the market for more throw oriented lamps, with his offering the "narrow beam" option. Perhaps a dedomed LED cpuld offer a "tight beam" option, with the disclaimer that the LED die is exposed, and therefore more prone to potential failure.

 

[Hogokansatsukan]

While Henry may not be interested in making LEP-esque all hotspot no flood pocket throwers, he at least recognizes the market for more throw oriented lamps, with his offering the "narrow beam" option. Perhaps a dedomed LED cpuld offer a "tight beam" option, with the disclaimer that the LED die is exposed, and therefore more prone to potential failure.

What is interesting is that when it was suggested on August 27th, 2018 (the XP-G3) there was so much vitriol and negative comments that I closed and locked the thread. It has been one of the best selling emitters in HDS history and is still outselling most other emitters.
One of the reasons I take suggestions here with 350,000 grains of salt (50 pounds).
We won't make anything "more prone to failure." That is exactly the opposite of the HDS philosophy. Again, the end user can do what they wish, and considering how easy they appear to be to dedome, then the end user can take the risk.
It is a bit like emitter swaps, but I would think this would have much less risk. HDS does not do them. We warn folks that there is a part of the electronics quite close that doesn't take being heated up well, and it may fail over time from being heated, people still do it, and I have a box full of dead heads that either died or started exhibiting odd behavior after these swaps took place.
That being said, if someone should mess up a dedome and the emitter needs to be replaced, HDS will not do it. You will be stuck buying a new head, paying someone else to do an emitter swap, or doing it yourself.

 

[greatscoot]

Does anyone have a beam shot of 2700K and Amber side by side?

 

[Hogokansatsukan]

Does anyone have a beam shot of 2700K and Amber side by side?

 

[kerneldrop]

It's been a long time since I've bought a light I didn't assemble but a 519a 5000k Rotary may bring me out of purchasing retirement