Reflector + collimator = reflective collimator

cuocuo

Newly Enlightened
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Nov 2, 2014
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It's already more than 10 years ago. One day, I got curious... Collimator lens vs reflector, which one would be better? Regarding this question, I think I am not alone, because I could find some other threads related to the same question.

It was a very hard-to-answer question, so the solution I found was having them together. To this end, a thin layer of aluminum was vapor deposited on the back of collimators. In the next figure, the left hand side is an aluminum deposited collimator, and the right hand side is a normal collimator.


mirror.JPG


unfortunately, this project was not so successful, because I didn't see any noticeable improvement of brightness even after the aluminum deposition. Maybe, that is because the backside leakage of collimators is quite negligible.
 
If I remember correctly, your theory about the efficiency of internal reflection inside collimators is spot on. I suspect there was some measurable difference, but probably not much.

In my opinion, and based on limited experience, a properly designed and manufactured collimator is by far preferable to a reflector because it allows the designer to control almost the entire output of the emitter in a relatively small package. My favorite beam is the one produced by my old (one of the first? Can't remember) Malkoff module, and instead of the tightly defined spot and bright spill it has a small spot that slowly dims as you move outward from the center. That is pretty difficult to achieve with a regular reflector, and the night-vision-preserving dim spill is nearly impossible to achieve without optics.

I would like to see more lights with optics, and the fact that so few are on the market is one major advantage Surefire has with many of their lights - and is, incidentally, one of the major reasons I would buy one of their lights if they ever decided to jump in the reasonably-priced uses-rechargeables market.
 
That is one mean looking optical collimator! I guess that's about it, but beamshot pics would definitely be appreciated. Just sayin'....
 
the "problem" remains ... even a very cheaply mass-mass constructed reflector is (almost) on par with such an extreme costruction and materials "needing" "solution".
and then there are the really good reflectors...

Also, in most applications main beam + spill is an advantage.


when there is anything other needed than the typical 8-10 degree beam - which reflectors are very good at - then the optic is easier/better.
Or, when small space is of main concern
Therefore optics (and possibly this hybrid part) will remain as alternative for very special, low number "Specials".
Like ... what is an actual one? :thinking: ... like Copperhead 1+2, SFs, ...


hasnt there been - some years ago - the idea of using some optical grade GLASS for an optic?
That sounded like a possible improvement in output. Anyone remember the outcome?
 
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The reason that collimator is called Total Internal Reflection (TIR) lens, is that the reflection is total. reflective coating at its back won't help. you may try using clearer materials to reduce output lost due to opaqueness.
 
check that picture here - of a REAL tir lens,
and notice, that the wall behind is illuminated
:rolleyes:

ap2ssu5i9tslyk704.jpg

so much for total reflection ...

thats why preventing "back losses" would make sense - with any optic
;)

by the way: just because some focusing device is made from "see through"-material, it is not instantly TIR.
In the case of cuocuo's part here ... looks like a Fraen OPTIC ... for sure no TIR
;)
 
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