I had never thought about testing the color shift.
Tonight, I’ve done a spectral analysis on Plain glass (Solarforce Stock), Expensive AR Glass, this lens, and ‘nothing’ as the control
I’ve decided to normalize the results and simply present it as a RGB variance. The normalization makes the lowest color channel zero and means the other color channels will represent the tint change.
(look carefully at the chart… everything except the 1% has a decimal before it…it’s just hard to see)
SF Glass
AR Glass
This Lens
nothing
R
0
0
+.3%
0
G
+.6%
+1%
+.4%
0
B
+.8%
+.5%
0
0
So, from the chart:
plain glass (Solarforce) makes the emitted light more blue/green.
Expensive AR Glass makes the emitted light more green/blue-green
This lens makes the emitted light more yellow (yellow is the same as red/green - or- less blue)
I’m having trouble seeing any color difference with my eyes.
The color shift is going to be very subjective for use anyway. According to your chart, and the LED I am running with mine (closer to 3000K) I do see a very slight bit more “yellow”. Not enough to really quantify though, as the other drop in with the same LED side by side with nothing in front of it, has variation between the tint when compared with the other. The LED’s will vary even in the same reel to some level.
I would say if you had an absolutely uncanny eye and a favorite specific LED tint in a light you carried all the time and put this AR lens in front of it, you may notice it. In two weeks or so of use, it would be imperceptible though.
I have been using the lens at work and a week of pocket carry with other tools and some loaning, no scratches so far, plenty of loaning out to others as well. I am impressed, and it wipes clean easily. I use alcohol on it for more than what a disposable wipe will do.
I ran 2 different dropins, one with a xpl dedomed led with a 6 amp qlite driver and another with a xpl hi with a FET driver and there were no detrimental effects on the lens that I could see. I ran the light on high with both drop-ins until the light was uncomfortable to hold and the lens was fine. I haven’t done any torture tests on the lens besides wiping it with a cloth (no scratches appeared). I still can’t get myself to try and scratch a perfectly clear lens but I’ll try later.
I have it installed and let me tell you… it makes a difference in light out the front and seems to clean up the beam. I did go out of the way to get it yucky (tech term) and then ran it in front of a very hot running drop in. It got hot along with the head and I cannot see where it was hurt. With a good cell and braids, I am getting about 4.2-4.3 amps at the tail.
Everyone doesn’t need to destroy their lens, but if one or two of you could judge how hard it is to scratch, I will send a replacement. I’ve ordered another sheet cut for Convoy M1. I really like the Convoy hosts…but, like the Solarforce, the glass lenses aren’t very good. The M1 lens will be a little thicker (1.5mm).
So far, what I’ve seen from the comments, it passes the clarity test and heat test. I’ve done the output test and it’s the best I’ve seen.
So all that’s left is the destructive scratch test. I know it won’t outperform plain glass, but from my testing…the AR finish is tougher than the AR finish on glass.
I will give it a shot tomorrow and report back…. I think even if when it scratches it is still better than glass due to the non shattering plastic.
II
EDIT:
Amazing scratch resistance. I started off just casually pinging a phillips head screwdriver against it. No real scratches I can see. When I broke the lens, it was being hit pretty hard with the tip of the screwdriver, hard enough that I would not have done it with a glass lens. The broken lens was still retained by the bezel, and posed no cut hazard what so ever. This is a big thing if you have the light in your pocket and take a tumble down some stairs or some such. I did not set out to break the lens, only scratch it, and I could not. I think Randy has found a heck of a good lens for his lights. These will be installed over a TIR and should provide plenty of robust protection for the light. I believe in the destruction video of his lights by Austin PD, the lens was the main thing that broke, this should fix that issue……
The smudge resistance has been terrific so far. I smeared grease all over the lens, and it came off with a t-shirt and a little bit of moisture within a few seconds. Good as new.
I can try to abrade the lens with various things over the weekend. In daily use so far, there isn't a single scratch.
Haven’t been active on blf the last few months, but I’m still putting this lens through its paces. I’ve rubbed keys across it (not forcefully), bumped into things randomly, and gotten automotive grease all over. After rinsing off the entire flashlight with soap, the lens looks as good as new (can’t say the same about the flashlight). It really is a great lens.
