Window frosting spray for flashlights...

This may be what some of you could use to diffuse your light's beam:

We ordered some new entry doors for our house that will have a small, half-moon shaped, decorative glass area near the top of each door. We did not want someone to be able to see into our house through this glass. So, we launched a search for something to make the glass translucent. We found a spray at the local craft store (Michael's) made for that very purpose. It's called Krylon Frosted Glass Finish. It works great. You simply clean the glass and spray it on.

It leaves the glass frosted, just like the label says. For our purpose, we wanted the glass to be completely frosted, but you can apply it as thick or thin as you like, which would mean it should be great for flashlight lenses.

Durability should not be a problem, since it is supposed to stand up to heat and sun light. Might work.

Just trying to help,

Chuck

Chuck:

Someone, I think Lambda, has suggested spraying smooth Mag reflectors, etc., with Krylon for some time. I would imagine that lens spray will provide greater diffusion (and wider and dimmer hotspot) than reflector spray.

It doesn't surprise me that someone else had found the frosting spray. I just thought it was my duty, as a good CPF'r /ubbthreads/images/graemlins/smile.gif, to report a possible solution to a known problem.

Thanks for the reply.

Chuck /ubbthreads/images/graemlins/wink2.gif

Frosted Glass Finish should be of help in diffusing the beam and taming artifacts. But I think you'll find that Lambda was discussing something related but subtly different.

What lambda suggested was using Krylon clear spray to form an uneven, dimpled surface that would disperse the reflected light. I believe the idea was not to form a frosted surface, but a clear surface with an orange-peel-like surface. Using a clear spray avoids turning the light into a flood light. It broadens the beam to a lesser degree -- just enough to smooth out the artifacts. It is my opinion that this is a difference which, although not intuitively obvious, will turn out to be significant in practice.

It's only an opinion at this point because it has only recently been the subject of some thoughts on my part. I am discussing the theoretical aspects of this with another CPFer and may later be devising some experiments to test a more general assertion that beam dispersion from orange-peel reflectors is more controlled and of a smaller magnitude than the dispersion from reflectors which have been abraded or frosted.

More info on lambda's technique is here.

Paul

If it can withstand the heat, why not just frost the bulb or tip of the bulb.
Larry.

Larry,

The bulb gets VERY hot. A sprayed finish would not work. A proven procedure is one suggested by Ginseng. He talks about etching bulbs here.

Paul