Diffuser for flashlights

Hello everyone. I am wondering how to get a smooth and even beam that creates a wall of light and does away with the hotspot. How can I do this? I have thought about frosted scotch tape. I want to try this on my Solarforce L2P light and see how it works. Would this create a problem with heat because the light can get hot?

I unfortunately don't have a good answer for your question, but if you are looking for that kind of a beam pattern, definitely look into a 'zooming' light like the Romizen RC-29. When in flood mode, it is a gorgeous flood light with a perfect even beam. Very nice to use. The DX version is 14500 capable and is very very nice!

http://www.dealextreme.com/p/romisen-rc-29-cree-q5-wc-3-mode-180-lumen-convex-lens-led-flashlight-with-strap-1-aa-1-14500-50679

A light coat of hairspray on the reflector can even out the beam without heavy losses of light - diffusers tend to drastically reduce the amount of light produced. Spray a small amount into the air and pass the reflector through it.

Simply removing the reflector from a suitable light may do the trick for you. It is pretty pointless trying this on a dedicated thrower with a deep and wide reflector though. Most AA lights do reasonably well without a reflector.

Whatever you do, don't touch the reflecting surface of a reflector - the coatings are very, very fragile and you will make matters worse trying to remove marks from the reflector.

I use some old 35mm film vials (remember those) they fit perfectly on the 501A or B and some others I am not sure of right now.

I never thought about that, 35mm film containers might work for the as needed solution. It is not a must have but it does help me a bit having a wall of light rather than a bright hotspot with little spill.

Sadly, I have to ask.. is there a good place to get those canisters nowadays? Everyone and everywhere is digital now, dammit. :P

try some glad press and seal from the grocery store. Just press it onto your lens and trim, put the lens back in the light and presto. Plus it is easily removable and cheap.

or...

Go to a professional lighting store (the kind that provides gear for concerts etc) and buy a sheet of diffuser film for <$20. You will have enough for the largest collection of flashlights. You can get many different levels of diffusion so you can get exactly what you want. Also a plus with this is that the film is designed to be in front of 1Kw + lamps so the heat from your flashlight won't be a problem. If you are lucky they may have some off cuts you can have for free.

My wife is a nursing student so I tried some medical tape which is frosted and a tad bit bumpy to the touch. She applied one piece to the outside of the lens of my Romisen for me. I will try it when it gets dark and see what I think of it.

Go ask at a London Drugs or Kerrisdale Cameras. They both still do film processing and they're generally happy to unload some on your for free.

Oh, and as for taping over the lens - it shouldn't cause any light heat problems. You'll lose output, though.

ShaoTech has a GITD Diffuser film you might try.

I tested one of these:

http://www.light-reviews.com/fastcar_diffuser/

There was supposed to be a sales-thread in CPF, deleted long time ago for some reason (not very weird...).

What can I say... I have not much experience on diffusers but these are IMO great!

They don´t decrease total output that much yet they (especially 10-layer) smoothen the beam nicely.

5-layer is good for example cheap light with horrible beam 1$ ebay lights, terrible ringy beams or just compensating an unwanted SMO reflector. This 5-layer still keeps some throw in your light.

10-layer? Holy ***!

Just a perfect floodlight. No hints of any artifacts or such or even hotspot. Hotspot becomes an area or blob of hottish beam..

This stuff widens the beam even from things like UF-H2b and rings are gone.

I like the way it removes the exact border from no-light -> flood.

Just did a test on my L2i (R5 driven at 1 amp) and my general house/outdoor close range light just got better...

1"x1" costs 2$ + some for shipping in a letter. I recommend (without any expertise on diffusers) and I would say well worth their price.

scotch tape seems to diffuse the beam bery well

you can also mist a fine layer of clear acrylic spray paint onto the reflector if you want something more permanent.

if you want something totally permanent, you can dip an aluminum reflector in acetone. this will strip the reflective finish from the reflector and just give you bare matte aluminum. you will lose some output, but the resulting flood effect is pretty awesome. it's an almost pure wall of light that throws better than lights that use diffusion film.

for something permanent you could try modifing a real diffuser for use on your light

This is a non destructive method? Or is it impossible to remove the hairspray without damaging the lens?

I havent had the best luck with hairspray, it does indeed diffuse the beam very well, but also leaves a sticky mess.

Those diffuser films, I use them behind P60 dropin´s glass so they don´t get lost at work yet are easy to take off.

Can carry them inside body if needed.

I have used window frosting spray on my lenses lately with good results .

Use the old photographer's trick for soft focus. Just smear Vaseline on the lens. Wipe it off after.

In normal situation, SC51 has about 50% wider spill than Solarforce L2i. In photo, L2i is at max (1.0A) and SC51 at H1. For naked eye, there´s not that much "hotspot" to be seen than in this picture. Camera seems to see it differently (cell cam, sorry).

The idea is to show how wide the edge of the spill goes with these diffusers, not much less than 170° or so :)