Film-Tech Forum ARCHIVE: screens

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Posted by Scott Norwood (Member # 30) on 07-08-2007, 06:18 PM:

For those who are projecting film and/or video at home, what type of screen are you using?

I'm looking at classroom-type tripod screens and it seems that no one sells these with a perforated surface. Is fast-fold my only other option if I need a portable perf or microperf screen? Unfortunately, a fixed screen and frame is not an option due to space considerations. I only need a fairly small screen (3x7', common-height for all formats), so a fast-fold seems like total overkill for my purposes. Ideally, I'd like a portable classroom perf screen where I could put speakers on stands behind it.

Also, what are the issues with small screens and moire patterns with LCD and DLP video projection? I will be running film for now, but may want to add video at some point in the future. I've run into these issues before with theatre-size screens and would like to avoid them at home if possible. Would I just be better off with a non-perf screen and the speakers in front of the screen and below the image?

(I'm currently using a freebie classroom screen, but I can't stand the glass-beaded surface and need something bigger.)

Posted by Stephen Furley (Member # 1277) on 07-08-2007, 06:33 PM:

I've never seen a perforated tripod screen, and I think it's unlikely you'll find one. To be honest, in the sort of setup where tripod screens tend to be used, high quality sound is not usually a priority, and the speaker(s) tend to be simply stood on the floor under the screen.

Have you considered a roller screen? I would go for a simple one with cords and pulleys, where the roller winds itself up into a small box fixed to the ceiling, rather than a motorised one. you can easily make them yourself, with any surface you like.

You may well find that the perforations look intrusive, at the close viewing distances you would be using with a screen that size. I read somewhere of somebody making a screen material with very small perforations, mainly for digital projection, but I've not actually seen it.

Posted by Steve Guttag (Member # 268) on 07-08-2007, 09:08 PM:

I use a da-lite electric roll down with microperfs. I definately much prefer the sound from behind the screen. The Moire problem is definately there (LCD projector). It really is a problem when the pixel size is of the same order of magnatude as the perforation size/density. Thus, larger fewer perfs are less likely to be noticable than microperfs from a Moire standpoint but you need to be further away from the screen so as to not see the perfs.

The problem with roll down screens (all) is that in addition to the extra cost, they all age poorly due to sagging. They are inherently unsupported so they stretch more in the middle from their own weight. "Tensioned" ones can stop the curling but they tend to accelerate the stretching in the middle faster than on the edges and the bottom corners being the most deformed.

I think my next screen will be a Stewart fixed one though. Their perfs are irregular due to how they are made and that seems to be break up the Moire pattern (I don't see it ever with Stewarts in movie theatres). Stewart really does have the best projection surface...however they are typically 4-5 times more expensive than other screen makers.

Posted by Cameron Glendinning (Member # 3516) on 07-22-2007, 06:17 PM:

A fairly inexpensive aproach is a timber frame with calico stapled loosly to the frame, paint with a matt white paint. Calico will shrink when the paint dries, giving an ideal cheap, non sound screen. Edge with black felt. ( I realise that fixed is not an option, but for 20 dollars others who read might)

Personally I have just bought a cheap inflatable 149" screen from ebay for back yard movies, frame is aprox 12' x 9', screen is 10.5 x 6. US $200.

[ 07-22-2007, 08:02 PM: Message edited by: Cameron Glendinning ]

Posted by Christopher Meredith (Member # 3767) on 07-23-2007, 06:45 PM:

What is the benefit of perforation?

Posted by John Hawkinson (Member # 1135) on 07-23-2007, 07:26 PM:

A perforated screen is (mostly) transparent to sound.
It allows speakers to be placed directly behind the
screen, both out of view and at mid-screen height. Of course, the perforations do reduce picture quality by a small but measurable amount.

--jhawk

Posted by Mark Gulbrandsen (Member # 72) on 07-24-2007, 07:12 AM:

quote: Steve Guttag
Stewart really does have the best projection surface...however they are typically 4-5 times more expensive than other screen makers.

I was told thats because of all the EPA fees they have to pay... lots of chemicals evaporating into the air to make their screens ya know.

quote: Cameron Glendinning
A fairly inexpensive aproach is a timber frame with calico stapled loosly to the frame

You mean Calico Cats....? How many cats ya gotta skin to make a decent size screen? Don't tell Brad about your doing this!

Mark

Posted by Cameron Glendinning (Member # 3516) on 07-26-2007, 07:45 AM:

[Big Grin]

Posted by Scott Norwood (Member # 30) on 08-08-2007, 09:29 AM:

Update in case anyone cares: I cheaped out and got a regular portable classroom screen from Da-Lite. The 84" square version has a seamless matte surface and works fine. Masking will be a challenge.

I spoke with someone at Da-Lite about getting a custom-made perf screen, but apparently microperf surfaces require tension on all sides, which means that I would need a fast-fold or a self-tension screen, either of which is significantly more expensive and harder to set up.

Someday when I have the space, I'll get a proper screen frame and a regular microperf screen.