Curved Movie Screens --- Installation Tips
Beaded screens, in theory anyway, have fall off on the sides when used with anamorphic lenses, but that is only true if the room is wide and people are sitting at a side angle. In most home theater situations you can arrange the seating the way you want so you can keep "patrons" sitting on axis. Think of a beaded screen as a mirror. Try to have the projector pointed directly at the screen; not on an angle. The brightest picture gets reflected directly back to the projector.
Try to cover up your speakers or paint them black and use black speaker cloth. Having the speakers visible has a negative effect on the illusion that the sound is coming from the actors' mouths on the screen. In movie theaters they went through great pains to figure out how to do this and the solution was to us a perforated screen with speaker behind it. With this setup, the sound IS coming from the image. In 16mm this is not practical (although I have seen it done) because light is at such a premium and a perf screen loses about 20% of the light through the holes. You can cover your speaker by hanging curtains in front of them. The curtain material can block the sound from your speakers -- almost any material will to some extent. I use a material called Chinese silk which is transparent to sound. It makes a real difference in keeping the illusion that sound is coming from the screen.
No matter what projector system you have set up in your booth, curtains MAKE the theater. There is nothing more classy as curtains opening as the picture starts. Aim some colored lights on the curtain (it's good if they are off to the side so they cast shadows from the folds to give it texture), put them on a simple dimmer and voile...you have a first run, flagship theater.
And now for the piece de resistance....and I don't give this secret away often, but here it is. You can make your image look absolutely spectacular if you CURVE the plywood that you are going to attach the screen material to. It is a harrowing process and you need to know what you are doing. You might want to get a carpenter in to help. But you just wet the wood and then set it up on a jig so that it can be bent. It then dries and the curve stays in. The curve should be VERY slight, only enough to be discernible to the audience. You can't make it so severe that you loose focus. 16mm lenses don't have nearly the depth of field that 35mm lenses do, so you have to be very careful not to introduce TOO much curve. But in fact, the physics of optics really REQUIRES a curve for perfect focus. Here's why. Let's say you take a string and attach it to the front of the projector....then you stretch it out to the mid point of the screen. Now that you have determined that distance....without letting out any more string, walk it to one edge of the width. You will see that it will not reach the edge because the left and right edge of a perfectly FLAT screen are not equidistant from the lens as the center of the screen. If you were to bend the screen so that the corners meet the string, that is the optimum curve where the image is in perfect focus all across the screen. This curve changes with the distance from the lens. The shorter the throw and larger the image, the more of a curve. The longer the throw, the less a curve.
Bottom line, a curved screen looks awesome!
But you say you don't want to do all that stuff....maybe afraid of ruining your screen material or your marriage. Here's a poor man's curve that looks great but is easier to accomplish. It's a perspective illusion. All you do is you take your top mask and dip it slightly in the center, so the height of the screen at the center is slightly less than at the edges. Now do the same with the bottom mask material. You make the center of the bottom mask dip UP into the picture so that you basically have curved the top and bottom masks to create a slight dip into the center. With the picture projected, yes, you loose a few inches masked off in the center of the screen but the loss tapers off to the edges so there nothing is masked, but that loss is insignificant and when I tell you it makes a HUGE difference in the perceived image size and quality....it actually LOOKS bigger and more majestic to the audience.
You have to take care that you don't create a V in the top and bottom masks, you must create a gradual curve from each corner to the center. I did this in one situation by just PAINTING the curve on top and bottom of the screen flat black to make the "mask." The top and bottom of the picture is always the same in either the scope or the standard format, so it can be just painted. However, velour is better because it absorbs light better and insures that you wont see the telltale bit of image that the curve is masking off.
Now, purists will scream that losing ANY portion of the picture is bad. Well, maybe, but masks are ALWAYS cutting a little of the image to get a sharp edge (which is VERY important to making the image look good). This just masks a little more at the top and bottom center than at the edges. If you were to go to a movie theater and see how much of the image is masked because of things like keystoneing (a problem you don't usually have in 16mm because your projection angles are not nearly as severe) you would not think 2 inches at top and bottom was anything to worry about. If you have doubts, try it with a temporary setup and I guarantee, once you see the curve, either real or perspective, you will never go back to a flat screen. But with the perspective curve, you will have to decide which is better for you....not losing the extra 2 inches or what the curve does for your picture.
(Editor....... Black masking around the screen makes for a great picture. I have dark black velvet panels hanging on curtain rods at the side of the picture. I easily adjust them for the correct ratio before screening a film. The top and bottom border is made up of black velvet covered plywood which is permanent, as I'm always projecting a 4.5' H picture.)