Not sure if this is really an instruction set or just a concept to share. It works very similar to 35mm adapters and shoebox lenses. Recently I was adjusting the focus on an old rangefinder camera when it dawned on me: what if I took a picture of the piece of wax paper I was using to check the focus? Pretty simple concept; the lens is projecting an upside down image onto the wax paper that is placed where the film should be and I could just take a picture of that. I fooled around with the idea and then I decided to make an instruction set for it, just so the concept could be shared.
Step 1: Materials
Old film camera (either with a bulb mode or one you don't mind removing the shutter mechanism from): I'm using a Polaroid 320 land camera, that I will have to remove the shutter from, mostly because it has a large film area, and I don't plan on ever buying film for it (plus they're really cheap at thrift stores).
A black bag, T-shirt, or some other type of dark cloth like material.
Another camera, your choice really but cheap point and shoot digital cameras have decent macro modes and are easy to operate with one hand; that's going to come in handy.
Scissors and tape (you probably already have some of these).
Wax paper, you can also use tracing paper, or any other semi transparent flat sheet of whatever you want to try.
Step 2: Open Your Camera
You want to take your film camera and open up the back of it, you should see an area that looks like an open box with a lens and shutter at the other side (the place where the film exposes at). If you need to remove the shutter do that (I had to do this for the land camera), but if it has a bulb mode you could leave it intact and just open the shutter. You may want to tape the back open. Especially if it's got a big heavy finger-pinching back like this one.
Step 3: Cut Wax Paper
Cut a piece of wax paper the size of that box, or window if you want to call it that. On the land camera this was easy: I placed a picture from it on the wax paper and cut it out in that shape. Overlapping shouldn't affect the picture so don't sweat it: cut a little bigger than you think.
Step 4: Tape Wax Paper
Tape the piece of wax paper down to the film plane (the open part of that box from earlier) along all the edges. You could make sure it was flat, but if it bows a little you'll get wonky funhouse images. You should be able to see a faint image now when the shutters open (or missing). If it's really bright where you're at then you probably don't see anything, that's normal.
Step 5: Put It in a T-shirt
Place the camera inside the T-shirt (or whatever you decided to use) with the lens coming out one of the arm holes. Then stick your head in the shirt. A-ha! See? Much brighter. You could tape it down and tight if you want, but if you're careful you won't have to ruin your shirt. This is similar to one of the old cameras you see in the movies where the photographer gets under the black cloth to see before he takes the picture.
Step 6: Get in There With It
Get your camera to take the picture with. Put it in macro (the little flower) mode and some type of night mode if you got one. It's going to need a lot of light; the image is much fainter than it looks when you're in the T-shirt. Aim at the film plane and take a picture. Develop, download whatever it is you do and flip it. That's it, that's all there is to it. Seriously, you could be doing this right now instead of reading this.
Step 7: FAQS
How do I remove the shutter from my (insert camera name here)?
Poke around with a screw driver looking for a way to take it apart, poke hard enough and you'll probably go straight through the shutter. Problem solved.
Couldn't you place a box with holes between the cameras instead of the T-shirt?
Yep. You sure could. I just happen to have more black T-shirts than boxes right now.
It's kind of hard to manipulate both cameras at the same time, isn't it?
Yes, I totally agree with you.
What if you made a bracket that held both cameras in place?
Well, you could probably sell that.
Will this work with a used disposable camera?
Sky's the limit, bud.