Categories
Quickie Projection Screen
So you’ve borrowed a video projector and you’re finally going to host that Don Knotts film festival that you’ve always talked about. Well, Cannonball Run II doesn’t look that great on a beige wall, and you don’t have any white sheets to hang. Rest easy, with a trip to the fabric store and a few spare hours, you can make yourself an admirable projection screen.
Get some blackout cloth
What you are going to need is some drapery blackout fabric. This stuff is a lightweight, white fabric with a rubbery coating on the back. It is sold at most fabric stores and is normally used to make a light-proof backing for curtains. The rubber coating makes it super opaque, which is perfect for making a highly reflective projection screen.
Build a frame
Figure out what aspect ratio and size screen that you would like, then build a frame to strech your blackout cloth over. I ripped down some 2×4′s that I had to make some 3/4 x 1 1/2 inch boards. I built a 90 inch diagonal 16:9 frame from these and added an extra cross member to the center for the sake of rigidity. I then cut some 12 inch gussets, screwing and gluing them in place to reinforce all corner joints. This made for a rather stiff and lightweight frame.
Strech the screen
I used a staple gun to stretch the fabric over the frame. What you will end up with is a dirt cheap, lightweight, projection screen. If you ever upgrade to a retractable model with automatic masking, you can always use this thing as a painting canvas.
As a person with a home-made screen, I’d offer the following advice:
After you’ve stretched the canvas, paint it with a flat white paint.
Why? Canvas is not opaque and suffers from a property called subsurface scattering. The light from the projector will penetrate the fibres and scatter back to the audience from various depths, leading to a certain amount of fuzziness in the image that no amount of focus-adjustment will eliminate.
A coat or two of white paint will sharply reduce this scattering and give you a picture that can be more sharply focussed.
Of course, if the projector you’re using exhibits screen-door artefacts (a black “grid” of lines between every pixel sometimes found in early DLP projectors) – a screen that has subsurface scattering can actually help to eliminate the screen-door effect, so YMMV.
> The rubber coating makes it
> super opaque, which is perfect
> for making a highly reflective
> projection screen.
So…are you saying, rubber-side-out?
Which side of the fabric do you project onto?
> The rubber coating makes it
> super opaque, which is perfect
> for making a highly reflective
> projection screen.
So…are you saying, rubber-side-out?
Which side of the fabric do you project onto?
Krust –
I did it fuzzy side out. seems to work well, but I think that I will also give the front side of the screen a coat of high hiding white paint like Crosius advised.
steve
I used a similar technique (gussets and butt joints) for the frame, but I used a 12 gauge vinyl shower curtain instead of cloth. The result is fantastic (fantastically cheap too – $5.32 for the curtain), although you are limited to the size of the shower curtain
You’ve missed a very cool and important part, which is “sizing” the canvas. The way artists stretch a canvas over a frame is not by hand (as you did, literally), but by…science! Canvas is made from cotton, a natural fiber, which shrinks when it comes into contact with water. So, the way you get a flawless, wrinkle-free canvas to paint on (or project on) is to staple the canvas on, but let it stay loose. Then, taking a paintbrush, paint a mixture of 1-part elmer’s glue (or primer paint) to 10 parts warm water across the loose canvas. The canvas will shrink, and become drum-tight within seconds. Follow with a thinned paint mixture and let dry. Perfect, super-stretched canvas.
Another inexpensive and way easy projection screen can be made with a 4′x8′ sheet of white masonite covered wall-board. I got mine at Home Depot for about $35. Just hang it up as is – it’s a semi-glossy, very slightly pebbled, very white, hard surface that makes a great screen. Easy to clean, too.
Yay for borrowed projectors and Don Knotts Film Festivals!
I made practically the same frame with stiles and rails, but used some leftover Tyvek house wrap. It seems to be a good mix between surface scatter, and surface sheen. The audience sees a fairly clean image withoug any hotspots (like you might see when projecting against shower board or white board material).
http://flickr.com/photos/btanaka/2527247124/