Driving photons up the wall

September 29, 2015 7:09 PM

What is a good cheap option to project an image onto a large wall for a outlining to paint?

I'd like to project an image onto a wall approximately 10 feet wide by 9 feet high (3x2.4 meters) so I can trace and paint a mural. The room is 14 feet (4.3m) deep, so I have plenty of space to use a projector - is that a good option?

I'm looking for the easiest way to accurately get the image onto the wall for painting. For level-of-detail reference, the current plan is for The Great Wave and I'd like to do more in the future.

I may have a friend with one I could borrow, but more likely I'm looking at getting some gizmo to project this for me. I don't need a really-great projector for gaming or videos, merely one good enough to project a detailed still image. Something in the $50 range would be perfect, definitely sub-$100.

Any product recommendations/sources for cheap projectors for wall murals, given my dimensions and requirements?

posted by bookdragoness to Home & Garden (5 answers total)

Best answer: I would buy a cheap used overhead projector (probably $10-40), and get a copy shop to print your image on a transparency ($1).

14' is not that much space for a cheap digital projector to make an image 10x9'. Check out this projection calculator.

Also cheap digital projectors tend to be very low resolution. Many ~$100 projectors are around 600x800 resolution. At 10 feet wide you're only going to have about 6 horizontal pixels per inch (10'=120" 800pix/120inch=6.6 pix/inch).
posted by gregr at 7:24 PM on September 29, 2015 [1 favorite]

If you can make a transparency of the outline (either by directly tracing it or using a copier to transparency sheets, tried and true technology) you could use an old-school overhead projector you find somewhere. Maybe from an old school.

On preview, yes, what gregr said. Maybe even an opaque projector.
posted by BillMcMurdo at 7:26 PM on September 29, 2015 [1 favorite]

Maybe you could find a junk used or free overhead projector for transparencies and print out the image you need on transparency film. My pre-turn-of-the-century high school and college used them extensively... there must be rooms full of them left in some places, all covered in dust.
posted by XMLicious at 7:26 PM on September 29, 2015 [1 favorite]

Best answer: Check with your local library. You may be able to check out either a video projector or an overhead opaque/transparency projector.

If you can't check one out there, check with your local hotel/conference center. They might be able to rent a projector to you

If that doesn't work and you can't borrow one from a friend, post an ad on a CL asking to rent/borrow one, or on fivrr or taskrabbit or whatever.

There's probably even an A/V company near you that rents projectors.

If you really just want to buy one, you can probably find a projector on ebay or CL that's at least 1280x1024, or 1080p which *should* be enough.

Video projectors are really the best for doing large mural traces/paints like this, though. Sure, the detail is sometimes a bit less than a good photostat/transparency projection, but you can do things with a video projector you can't do with an analog projector.

Things like focus and keystoning and skew to make sure it's all lined up right. Or using multiple images with perfect registration so you can, say, use a high contrast outline for the outline trace, then switch to a full color image to grab finer details.

But basically any video projector will do, even one of those pocket pico-projectors. Any one you use is going to have pixels at that detail level that you'll have to artistically interpret, but I've done this many times and it's just part of the process.
posted by loquacious at 10:35 PM on September 29, 2015

Best answer: Paint the negative, so that you're painting a black line over an illuminated line on a dark wall.
posted by sebastienbailard at 12:38 AM on September 30, 2015