Film-Tech Forum ARCHIVE: Silver screen paint for 3D -- Source?

This is topic Silver screen paint for 3D -- Source? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Frank Angel (Member # 248) on 02-19-2019, 08:08 AM:

I know in the 80s when they brought back single strip 3D, theatres used to spray their regular screens with a silver paint -- a down and dirty fix just so they could cash in on a 3D run.

Was there a paint that was specifically formulated for this? Would theatre supply outfits carry this stuff or would any paint with high silver content work? Anyone know of a specific brand that can be used to retain polarization?

Posted by Alan Gouger (Member # 543) on 02-19-2019, 10:26 AM:

Paintonscreen
I tried this years ago when I built a DIY silver screen. This stuff really works. They make a silver option that maintains polarisation.

Posted by Steve Guttag (Member # 268) on 02-19-2019, 10:26 AM:

Technikote sold it (defunct) in the '80s. It didn't do very well, in my opinion.

I'm sure screen paint is available since IMAX, last I checked, sprays their screens in the field as part of their installation.

Posted by Marcel Birgelen (Member # 6801) on 02-19-2019, 04:00 PM:

Most metallic paints will work to some extend and will retain most of the polarization.

Most modern "silver screens" actually use a form of aluminum flakes as their "silver coat", not real silver, which would make the screens not only ultra expensive, but also far heavier.

Posted by Dave Macaulay (Member # 813) on 02-19-2019, 05:58 PM:

The paint is not hard to find, pretty much any aluminum paint will work. Getting it on smoothly/evenly is a big problem.

Posted by Sean McKinnon (Member # 612) on 02-20-2019, 09:41 AM:

I hope your not considering doing this Frank! There are options out there for 3D screens that are not AS bad as traditional "silver" screen. I have used the Harkness Clarus to pretty good results. In my opinion it does still have a hot spot and stilll looks directional to me but it is much less so than a comparable 3D screen. I would actually take a regular high gain screen over paint any day as I would think its near impossible to get it coated perfectly. Also what do you do about the perfs?

Posted by Mark Gulbrandsen (Member # 72) on 02-20-2019, 02:56 PM:

Can't tell you how many old screens I switched out that had been painted silver in years past. Probably for the 3-D days in the 70's, but I can't imagine that it ever worked out very well. In fact that whole 1970's 3-D thing was kind of a bust. All screen manufacturers keep their paint coatings as closely guarded secrets...

Mark

Posted by Frank Angel (Member # 248) on 02-20-2019, 05:05 PM:

Thanks, guys. This is not a theatre -- it's a down-and-dirty room students want to use to screen their video projects on a wall (no perfs, Sean). Basically it'll be use for what would be the video equivalent of "rushes" or "dailies." Since they have already made the decision to paint the plaster wall as their screen, when someone asked if they could do passive 3D on it, I thought, possibly, but of course they'll need a silver paint instead of white.

As for evenness, that will be the biggest challenge for sure. On the other hand, they are students and whether it works or hails and they need to buy a real silver screen, it will be a learning experience for them.

Posted by Carsten Kurz (Member # 5396) on 02-20-2019, 05:10 PM:

Don't know which constraints they have to follow equipment wise - but in general, shutter glasses are easier to do than passive. Passive 3D is the better solution if you need cheap glasses for many users (as in cinema). For a small number of users, shutter glasses is the cheaper and easier way.

IMAX used a huge automated rig to paint some of their silver screens on site. This probably got it close to what screen manufacturers can achieve on their lots. IMAX may even have bought that rig from one of the major screen manufacturers.

- Carsten