Yeah sorry about that. I cant work out how to find it does this help?
#_d6I3SJh#
Edit
I use the app on my tablet. This is what I get when i copy the item number. When ever I look for something in a browser it takes me to the german site.
To view 【AU $109.23 15%OFF | K9 Large Optical Glass Magnifying Glass Lens Focal Length 385mm 319.5mm Plano Convex Lens Dia 178mm 145mm Big Plano-convex】 on AliExpress with code #_dVTdqFZ#, copy the whole sentence and open the app.
Thanks for the link. The convex lens on Edmund is interesting. For maximum throw on flashlights, what is the difference between using an aspheric or a spherical lens?
Doing some searches, I find aspherical lens are like a lottery.
Did you machine your own collar? How?
Aspherical lens is like having a very short focal length and I cant get the ones I have to focus properly. My idea originally thought was to use one to do away with the RLT but didnt work like I thought.
I have had a go at making the RLT out of stainless steel butt weld dome endcaps. These do work but i cant get the numbers I have seen quoted but then again I cant seem to get the numbers right anyways. I also brought a marinebeam for the collar to compare with the ones I have had a go at making.
I also think the aperture is fairly important and should be adjusted according to focal length. For the next ones I have got some round nose router bits and I will bore the aperture before I cut.the hemisherical surface.
It would be very interesting to see how your collar compares the th Wavien RLT
One idea that just came to mind after reading your comment,
You could resin print a collar, polish with a steel ball bearing, and then mirror coat it.
I reckon this will visibly change the beam intensity, it cant not.
Yo…… Is that a gutted W30 or L2K?!! XD
Please post more pics O:
You could boost your driver up a bit like Vinh from SkyLumen. His boosted W30s are all 2.1~2.7Mcd
May I get an approximate measurement or size of the “right angle prism mirror”, the one that is visible above the yellow phosphor? I am building my own LEP and need to figure out about what mirror size to get.
I should not have been posting yesterdy but I will leave it here for the pics might even remember what i was on about…. and canexplain or add more pics.
Funny I do remember what I was on about. So I will fix the posts up that make no sense.
it is a w30 that I cut off and turned a flange on the end then made an adaptor that slide the torch a retaining holds it in place. The adaptor is the same size that I use to screw in to lots of different lens setups
This didnt work the aperture was to small and blocked the light. but it did make a visible increase to the beam.
Some pics of a few lenses half built. Not excactly sure what LEDs are going in them yet.
Few things to keep in mind that I have worked out through trial and error.
-The total length of the lens train can be no more than the focal length of the primary lens
-For max throw the secondary lens is better closer to the LED
-For maximum lumens down the paddock the secondary lens is better further way from the LED
-a longer focal length lens is better than a short focal length
Very interesting. Would it be possible to take the following measurements for comparison:
a) LEP with only primary lens
b) LEP with RLT and only primary lens
c) LEP with RLT and both lenses?
Please 
I cant really take accurate measurements. One reason I have 3 W30s is I use them as my control lights. Other than that I like them I dont have a real need for one. however I am interested building my own LEP in a different configuration. But will require a different thread.
In the W30 underneath the window you see there is a about 10mm PCX lens with the belly out. I am not sure if it is there for one purpose or two but it will throw all your lens calculations out. Putting the rlt collar on makes it hard to focus because you are trying to reflect light back through a lens. And it is impossible to get the LEP into the collar any further.
that is where the secondary lens comes to the party It can be at half its focal length or closest to its lens to collect more light to direct to the primary lens.
You have to remember that something like blacking out the inside of the lens housing could give more noticable result than spending months trying to get more light.
To add to that I everybody has their own way of doing things and Im not having a go at you i can just be a little crude explaining things
Really thank you grin for taking the time measuring the prism mirror and collar! Much appreciated.
Some tips:
Stainless steel is not a suitable material for making a collar. A collar relies heavily on reflectance of blue light which re-excites the phosphor of the LED. Stainless steel has a low reflectivity in the blue part of the spectrum. Also, you need an actual coated mirror for max performance. Polishing a piece of aluminium will still not be good enough, but should be better than stainles steel. Wavien collars are dichroitic glass mirrors, those have around 95% reflectivity (or better).
If you want a pre-collimator that collects all of the emitted light of the LED and doesn't reduce the luminous intensity you need to use a short-focal length spheric (not aspheric) lens that you position right above the bare die of the LED (less than 1mm above it). See here for an example (it's in German).
mate wtf
coming up for a quick drive to check these out, chopped up w30 :o
Why should the pre-collimator be spherical? Not to mess with the asphericity of the main less?
I'm not sure in this case, it's just the experience of multiple people including me. These kinds of lenses always produced the best results.
* yeah first atempt was successful. I cut it by hand meaning I used a srcew driver to turn the chuck. Excuse the language but very rarely does something work with the first idea and the very first attempt. I havent tested it in a light yet but it gets a hot spot exactly the same as the one I brought. Now I can custom make the with fine tuned aperture.
I understand what you are saying about the materials, the stainless steel was laying around looked about the right shape so why not and It does make a visible difference to the beam.
Now that I know I can cut them I will look into silver plating. There are also places that can apply a protective coating. But what you are saying is it is in the actual glass. Well that makes it hard to reproduce at home then.
The small lens above the phosphor in the W30 is probably spherical then. I will have to have a closer look. You are obviously using it behind the collar which makes so much sense. The lense focuses the recycled light back and the collar provides the aperture. I had not got around to putting the lens directly on the led yet. Now you say that the W30 makes much more sense now.
Haha thanks for that, there goes another 6months
From my own experience i concluded the precollimator lens should be aspherical too.
Not sure why others conclude differently.
Maybe in between is best, i dunno.