All Flood Aspheric-Diffuser Mag Mod

[mrmike]

High power lights are fun, but sometimes the hotspot is too much, and what you really need is all flood.

There are all sorts of ways to concoct diffusers, and I wanted to share this particular experiment of mine, which is a continuation of a previous project: http://www.candlepowerforums.com/vb/showthread.php?t=146478&page=9

Diffusers are great for killing off that glaring hot-spot, but most are translucent, and really cut down on the amount of transmitted light. I was looking for a better solution...

Some time ago I worked for an art supply company, and we sold 3M Scotchlite "Retro-reflective Glass Beads". They are used by sign painters to catch/reflect light; to really make their signs stand out (especially for fancy jobs like firetrucks and ambulances). You see the same beads used on highway signs, and the reflective material on running shoes.

The Scotchlite beads are painfully expensive, but you can get them much cheaper from industrial supply catalogs or some arts/craft stores.

In this case, instead of using it as a reflector (to catch your headlights for example), I'm using it as a diffuser. I took a 50mm Aspheric Lens, mixed up some 5-minute epoxy, brushed it on the curved part of the lens (I used masking tape on the flat side for neatness), and dumped the glass beads on top of the lens. I poured it on until it was entirely covered in a mound of beads, and let it set a few hours.

The Light is a 4-D Mag, with a Terralux TLE-300M. I used a cheap ($5) Surplus Shed 50mm Aspheric (why use an expensive coated lens when I'm going to cover it with epoxy and glass?). The battery in it is a stick of Elite 4500s. The six cell stick usually tops off around 8.4 volts, so when used in a previous ROP project it habitually fried the bulbs. It works beautifully with the TLE-300M.

There's a UCL lens mounted in the head. When I want to use the diffuser, I just set it on top of the UCL lens/head, and hold it in place with the anti-roll widget. It works almost too well.

UCL Lens, no Aspheric-Diffuser (far and zoom)

With Aspheric-Diffuser

No diffuser (left).......... With diffuser (right)

Ceiling Bounce, no diffuser (left).......... With diffuser (right)
Wow, flashlights really make the ceiling look disgustingly dirty... such are the joys of forced air heat

I'm trying to get a better picture of the material so you can see what it looks like. This is looking at the flat/plano side of the lens, illuminated from behind by a Fenix E01 propped up on my NDI.

And here's a view from the front/convex side, once again illuminated by the Fenix E01 instead of the Terralux, to avoid killing the image with glare.

I think it works very well. Obviously you could do this with a Malkoff, or any flashlight. The Mag anti-roll rubber gadget makes it easy to add/remove such a lens to any C-cell/D-cell Maglite.

Is the coating tough? It's epoxy and glass, so although it looks fragile, it certainly is not.

 

[Nos]

glass beads and in epoxy, clever idea. i guess you wont loose to much output with this solution oo:

edit: easy fast and cheap too. hmmm ill try this myself

 

[Stereodude]

Pardon the stupid question, but what benefit is the aspheric lens in this case? Wouldn't putting the same epoxy and glass bead combo on a standard flat glass lens work just as well?

 

[f22shift]

you could also used this spray on frost paint and control how diffused you would want it.
http://www.candlepowerforums.com/vb/showthread.php?t=186717

 

[Nos]

of course. a simple lens would work....but where is the fun? i often thought about the beam how a diffused aspheric would look like :tinfoil: if it is just floody or smooth with some remaining throw ..... the results look interesting..... mrmike, could you maybe add some open field beamshots, so we can get a look at the whole beamprofil?

 

[sORe-EyEz]

photographic glass filters do come in varying degrees of frosting- mostly mild.

did replace a Mag 3C w/ 1 such filter but with the metal ring encasement removed. the fit was perfect.

 

[mrmike]

Stereodude: Pardon the stupid question, but what benefit is the aspheric lens in this case? Wouldn't putting the same epoxy and glass bead combo on a standard flat glass lens work just as well?

When I bought the lens it had a scratch in it. I wasn't sure what I wanted to do with the lens... in this case the scratch obviously becomes meaningless; and like Nos suggested, I figured it would look cool.

 

[Gunner12]

Actually, an aspheric lens with the light source not at the focal point will produce a pretty even spot by itself. But it will be a pretty clean round spot of light instead of what you have, a well diffused light.

But I'm not sure how that will work with three light sources.

At least the lens is now useful.

 

[Crenshaw]

a diffused aspheric? theres an oxymoron...

nice one though! :thumbsup:

Crenshaw