How to make like a movie theater?

January 24, 2006 2:49 PM

Projector question: Does any know of a consumer level digital projector with a fairly long throw distance? Or any DIY solutions for increasing the throw distance on a projector?

I've done some googling and found various expensive conversion lenses and whatnot, but I'm curious whether anyone knows offhand of something better. The goal is to project from the back of a medium sized movie house onto the screen and not have a huge overlap of the image outside of the screen boundary. Secondarily, less 'screen door effect' would be nice, but we're not too picky where that's concerned.

I have a projector that I recently purchased for home use, and we've tried that one and it's okay, but just too large from that distance.

Any DIY solutions for increasing your throw distance?

Thanks guys, you all rock hardcore.

posted by Silent Thomas to media & arts (8 comments total)

Can you get a replacement lens for this projector or is the lens not removable? You need a longer focal length. Also, is your projector bright enough from this longer distance?
posted by caddis at 3:23 PM on January 24, 2006

Yeah, actually the brightness isn't an issue. I was kind of surprised by it, but it looked okay.

I don't know if I can replace the lens, actually... I don't think so, based on how it looks and the fact that it's a fairly vanilla type of consumer item, but that's a good thing to check. I've seen some add-on lenses, but they're pretty dang expensive, in the 600-1000 dollar range.
posted by Silent Thomas at 3:28 PM on January 24, 2006

Sounds like you are on quite a budget. Most consumer products do not feature interchangability as the focus is on convenience as opposed to high end image quality. For the most part, anything is going to cost some money and probably more than you have (if I am reading your post right).

I have done this a few times before. That is, try to create a "theatre" setting where there is none. The good news is that there are quite a few tricks to creating a good cinema experience even when the situation is far from perfect. Including the fact that you may have a projector sitting out in the middle of the audience. The even better news is that you can do it on the cheap with a stop to a dollar store.

If you could elaborate on exactly what you are trying to achieve, the physical setting and what you are showing, it would help with giving pointers.

FWIW, I have projected in theatres ranging in size from backyard picnics for the kids to IMAX. I am not the total expert, but I have some rabbits in my hat.
posted by lampshade at 3:42 PM on January 24, 2006

Oh, some details, sure:

It's an actual theater, about three hundred seats. The tech setup dictates that I can't mount anything permanent (from the ceiling, etc) and I really need to have the thing sitting all the way at the back of the theater, where the power is. The feasibility of running power to the ideal location (middle of the theater at the proper throw distance) just isn't there... someone would trip, sue us, and then it's the poorhouse for me for sure.

The specific problem is that with that setup, the projector's farther back than it's supposed to be which results in the image being way too large on the screen. The goal would be some way of forcing the image smaller from back there, preferably without spending a thousand bucks.

As far as what we're showing it's just dv-grade video we've put together. I'm just looking for budget ways to preserve that cinema experience. Again, thanks for the help.
posted by Silent Thomas at 3:55 PM on January 24, 2006

If you can't move the projector, that really limits you, and I seriously doubt there is a pop on lens solution. Fortunately, you have the image brightness. There is at least that.

Make a bigger screen? It is easier than you think. If you have the space, you can build a frame similar to a standard theatre flat which may fit the image. Skin it with white plastic. It is cheap and easy. 1x3 boards for the frame with corner braces of luan. Get some old banner, flip it over and you probably will have a large white surface, unseamed. Stretch it to the frame.

Alternately, piecing together foam core (foam boards) is an easy, stable and lightweight way to create a quick screen.

Crop the image down and add a video matte? If you could resize the image and add a black border in the video image, that would be the first part. Masking the edges of the projection surface so that ambient light that seeps through the image matte would be lessened when projected could make the difference. There would be some sharpness issues as you are spreading out a smaller source image into a larger area. Also, the projector beam intensity is brighter towards the center which may create some wash-out.

Hope this helps.
posted by lampshade at 4:37 PM on January 24, 2006

These may give ridiculously bad distortion, but you could always try taping a normal lens on the front.
posted by fuerloins at 4:40 PM on January 24, 2006

Can you tape extension cords to the ceiling? (Hence the projector is in the middle, and nothing's permanently mounted.)

Projector Central can search by throw distance.
posted by Aknaton at 5:56 PM on January 24, 2006

I would suggest a rental house for the projector and lens.

Should cost between $200 and $500 per day, depending on the lens, the projector and if they are willing to discount for the arts.
posted by tomierna at 12:38 PM on January 25, 2006