This is a short tutorial on how to make 3D anaglyphs with Photoshop. Please note that I don't have a degree in 3Dology or anything- I just figured (it out) when making pictures for myself, so any corrections or suggestions are welcome.
Anaglyphs
Quick background info for those not in the know: anaglyphs are the 3d pictures
that require red/green or red/blue glasses for viewing. Someone else can
probably list some commercial programs or plug-ins that will help you achieve
this effect, but I've gotten good results just using photoshop. These
instructions are for making full color, left-eye-red right-eye-blue images.
Get Two Pictures
Step one is to get two pictures of your subject, taken at exactly the same time
but from a few inches apart. An easy way to do this is to get two disposable
cameras and tape them together side by side; the two lenses (and the two
viewfinders) will be about as far apart as your eyes are, and that's crucial.
To take a picture with your double-camera, just point it at you subject, hold
it _very_ steady, and press both shutters. It's not perfect, but it's cheap. :)
Digitize the Film
Step two- develop your two rolls of film and digitize the pictures you want.
Getting a photodisc made from the negatives would be great, but you can just
scan them in with a flatbed scanner as long as they're straight- if one of the
pictures is scanned crooked then they won't match up in photoshop.
Make Magic
Step three is the photoshop work- make a new photoshop document, and paste the
two pictures in as new layers. Figure out which picture is the left-eye
picture- it's the one where everything is shifted to the right (meaning it
contains stuff on the left side of the frame that isn't in the other picture).
Hide the right-eye picture for now.
Making sure you have the left-eye layer selected, open the "channels" palette.
It should list RGB, Red, Green, and Blue channels. Click on the Green channel,
choose "Select All" from the Select menu, and then fill it with black. Fill the
Blue channel with black too. Then click on the RGB channel, and go back to the
"layers" palette.
Repeat the last step with the right-eye picture, only this time you only want
to fill the red channel with black; leave the other two channels alone. Move
this layer in the layers palette so that it is in front of the left eye.
Magic time- Make sure you have the right-eye layer selected, and look for the
drop-down menu at the top of the layer palette which lists the compositing
method for this layer. By default it will read "Normal"; you want to click on
this drop-down and change the method to "lighten".
What you will now see is the blue/green channels from the right image, which
are only visible through the right lens, superimposed on top of the red channel
of the left image, which is only visible though the right lens. In order to get
a proper 3D effect you have to line up the two images; you'll notice as soon as
you try that they won't line up exactly, because they were taken from different
angles. To get them to line up, try one of these methods: