Roughly percent light lost, reflector verses zoomie?

LED Flashlights – General Info
1

Does a good reflector flashlight waste fewer photons then a flashlight with a zoom lens?

I got a nice flashlight,

http://intl-outdoor.com/xintd-c8-v5-xml2-u4-multioption-18650-flashlight-p-308.html

that I had hoped to use on my bike. Problem is the spill and the spot, I want neither but I also don’t want to waste photons. Could a lens be fitted to the flashlight above to de-focus the spot and refocus the spill so that most of the light evenly illuminated some circular region perpendicular to the light beam (probably not optimal for bike riding but good for a start)?

Thanks for your help!

2

Would it be simple to change the shape of the reflector to get the same effect, well confined uniform light beam with fewer wasted photons? I want a well confined beam so I don’t blind people in oncoming cars.

3

A reflector light does waste less photons than a zoomie. A decent zoomie in flood modus wastes about the same (but a bit more) as a reflector light, and it gets worse and worse with zooming in.

But it sounds like you'd be most happy with a bycycle light with TIR lens. The one I currently use for cycling is a light with 25mm quad TIR (it is a RGBW light, so for cycling only the white tiny TIR is used), and it is the one that works best sofar.

4

I had to google TIR (total internal reflection). Do you use a stock bike light?

Thanks!

5

Goggling TIR bike lights came upon similar thread, “Reflector vs. Optics: Light Loss”

http://www.candlepowerforums.com/vb/showthread.php?151836-Reflector-vs-Optics-Light-Loss—.

6

That is a very clever idea. I tried it with an A6 and a 38 mm. zoomy lens. It works! Though I get a hole in the center, so it might take some fiddling to get it right. The principle is that the lens partly focuses the spill, like in a zoomy partly zoomed in; and it defocuses the spot simply because it is focused by the reflector, so either a concave or a convex lens with tend to spoil that focus.

7

You can get an OP reflector for your C8 which will increase flood at the cost of some throw. An easy drop-in mod and cheap. Or just get another C8 from FastTech where they have a few pages of tint/reflector options to choose from, all under ~$20 IIRC.

Phil

8

Thanks for that! I’m learning so much. I guess I should do more research before I buy something. Amazing options at FastTech. It is a great time to be a nighttime bike rider.

Thanks again!

9

Mind that budget lights usually have some design flaws, leds may be fake and very very cool white, and that the lumens are overrated. So if you're fine with fiddling to get it right, and checking here about a light before buying, a budget light is for you.