Spray on diffusion?

[Rick Burnett]

I figured this would be the best place to ask.

Is there anything you can spray onto a UV filter that would dry AND diffuse light?

I want something that isn't going to scrape off easily and that I can attempt to get an even a coat as possible. I have some experiments I want to do for anti-moire and want to build my own rescreener filter.

[Nick Gardner]

I have used aquanet on a clear filter before for a custom diffusion filter. It can be tricky to get the look you want, but it can look nice. Your AC will hate you when he has to get it off.......

Nick

[Rick Burnett]

Excellent! I was thinking of using that. I don't mind sacrificing a few filters. I just wanted to make sure it works! :)

Basically I am just experimenting with anti-moire stuff and want to see if I can put something together that is cheaper that ~$130 it costs for caprock which I own so I can compare. Mostly I'd like to see if I can tune the quality to help the 7D :)

[David Mullen ASC]

A properly designed diffusion filter has clear areas and areas that defocus the light, so what you get is a sharp image and an out-of-focus image layered over each other. Bad diffusion filters mainly just throw the focus off a little.

So it's very hard with the whole "spraying hairspray onto clear glass" technique to end up with a filter that doesn't simply just blur everything too much, because you can't get the mist particles to be evenly spaced enough with clear gaps between the particles. I know, I've tried it. With enough attempts, you end up with something OK for a dream sequence but it's not a good way of diffusing the image. You're mainly just throwing the focus off slightly.

[Rick Burnett]

Thanks David. I was worried about that. My idea was to use something from the craft store with holes punched in it, or anything with regular hole spacings to use as a mask then spray from a distance. Mainly, I just want to see if any other patterns help the 7D for anti moire/aliasing, but the more I think of it, the more trouble it will probably be.

I've seen some examples of the caprock 2.0 with the 7D and the images still looked plenty sharp to me. Now having received the filter, I saw that it was just as you describe here, little circles of diffusion generating areas and then clear glass. The diffusion parts are SO slight it would probably be almost impossible to do that in a way that makes any sense. I am just going to get what you describe.

Might still be fun to play with. I have not used the caprock yet since I literally just opened the box, so it will be interesting to see how it works. This is reaching into an area I've not work in too much so I have a lot of experimenting to do.

[Joe G.]

What if you shot the spray through a mesh screen?

[David Mullen ASC]

Something like that may work. In fact, who knows how they distribute the mist particles for a ProMist, etc.? Maybe they use some sort of screen... Or maybe their sprayer is designed for an even distribution of droplets.