+1. Not all AR coated glass is the same. Some are incredibly purple which looks cool but makes me think that it reduces light output. The AR coated glass on my TN31, TN30 and XinTDV5 are very good as there is only a slight tinge of purple, Kaidomain P60 is quite good also but also heavily coloured. My BTU Shocker AR coated lens is also very heavily coloured.
I like the lenses from cnq, I have all sizes and some new on order(58mm is sadly out of stock). They are cheap and definitely better than stock lenses which have no coating and even sometimes are kind of dirty.
Which size has the x6? That seems like the best canidate.
I also have the need of one lens around 70mm for my 9T6.
@tomE what does such a custom lens cost? I have read here few times of lenses from him but always thaught that this is only for the rich guys…
I recently checked one of the available lenses and it was 7$+7.5$ international shipping which is compared to the 3$ from cnqg quite expensive…
By the ways has anyone real scientific infos about the “grade” of coating and the correlation to the colour. I have for example glasses with lenses from Zeiss with the best coating which was available and it is green not purple…
Edit: Just googled it and it seems that the number of coatings is the key to sucess, because every coating can only wipe out reflections of specific wavelength.
The “green” glasses have 8 layers and purple layers often have 4, the light blue(like the cnqg) have one or two layers of anti reflective coating.
I am not sure if it is as simple as that, there's different types apart from numbers of layers. And some types are tougher than others, to name another feature of interest.
If I had a variety of AR-coated lenses I could do a simple test measuring the transmittance of them, but I have too few to make it interesting enough.
Not sure how much it would complicate it, but spectacles often have other coatings like scratch resistance too.
Just read a bit further and it seems that the transmission is only for special wavelength, which makes sense if any layer only make a specific wavelength passthrough. So we need a special ledlens which lets all the led light out, other things don’t matter.
Just took a look into the x,ml2 datasheet and there is a diagram on page 3 which shows the wavelength.
I hope that our lenses have coatings that let the complete visible spectrum through ;-)
Just kidding, what you ideally want is that the coating stops reflections, from all wavelengths. There are three things not ideal with available coatings: 1) the reflections are not stopped 100% , more like 90% if the coating is good, 2) it is a bit wavelength dependant, but again, a suitable coating is less wl dependant, 3) it is angle-dependant: at light angles further away from perpendicular to the glass surface the AR-effect does not work that well, and especially this effect is dependant on wavelength, that is why at an angle coatings have a colour.
The coating having a colour is often confused with the quality of the AR, but it does not neccessarily say everything about it. A less coloured AR-coating may indicate that it is 1 layer and not so effective, but can also be an extremely good multilayer coating.
I have also read somewhere on blf (about an Eagletac light) that a strongly coloured AR-coating transmits less light and influences the light colour, because of the strong (blue in this case) colour. But because the colour is only produced by light at a high angle this effect is negligable comparwd to the total transmission, it does therefore also not affect the light colour very much, only slightly at the edge of the spill.
On a side note: I like a good coloured AR-coating, it gives a classy feeling to a flashlight 
Will the AR glass be the same glass used in the existing AR lenses you sell? Some of those were measured well in my crude testing here.
Yes, same quality and finish…
As to Xintd X3, any one knows the exact size?
Ric
I forgot about your thread :-) . When I'm back home I will measure the transmittance of the few AR-lenses that I have and post it there.
48.9mm x 1.6mm
Many small 18650 flashlights use 20mm lenses. For example convoy S-series, and other oem versions. It will be great to have quality AR Coating lenses for them.
20mm are easily available through IOS
aim for whatever’s not available already, e.g. from http://www.flashlightlens.com/
(in fact, might whoever runs that site be a buyer for newly available sizes?)
+1 on 31.8 or 32, for Convoy M1 and 20mm.
Any updates on the Xintd x3 lens? I would buy multiple if it fits properly…
I would involve someone somewhere (say: you, and: here in this thread) saying: "who's in for a Xintd x3 lens, I will make a list", and then watch your list fill up and pray it gets to 50 :-) Then ask Ric to have them made and make a page for them on his website.
(I do not own a Xintd x3)
would a 50mm fit in the xintd x3? then it could cover a range of lights (mag, a60, tr1200), and seems to be the one of the more rare/expensive AR lens sizes
can there be plastic coated sheets like A4 format for example and we can than gave the form and cut easy for our-self as we wish? just an idea if its stupid just ignore …
Please add the Yezl Y3 lens (56.8mm x 2.04 mm), but I see you are offering it already on the GB.
Ric, any updates?