Ive been experimenting with creating 3d photos. Reptiles are ideal candidates because they tend to stay in place without moving for the second shot necessary for the 3d view. Unless you have an actual 3d camera you need to take two separate shots, moving the camera only in one dimension, to right under normal viewing conditions.
Two pictures with parallax differential are used to create combined image. The parallax distance depends on how close the image you are focused on, and how much you are zoomed in. To prevent movement between still use a tripod, and lock down all the movement knobs when you are focused correctly. For the next picture (the parallax view) you must move the camera to the right (or left but right is easier to remember when I process them) exactly level (since your eyes are level).
The exact distance to move the camera varies. For close ups, I move the camera between 1mm and 5mm. For views out to infinity, parallax distance increases upto the distance between your eyes (2.5" approx.). If you are not sure, take a series of photos. Digital cameras are ideal. If using developed film, the pix must be scanned identically. Digital cameras seem to make this easier as developing and scanning steps, sources of parallax error are eliminated.
The software: You can buy development software with vrex's 3d glasses for another 30 $. Simply paste right and left images into the stereo pair setup. I open forty or so images in ulead photoimpact, corel webphoto or adobe photoshop. (for some reason photoshop will only open 26 images at once). If you follow my system, take the 1st photo as the left side. Paste it into the left on Depthcharge preview window. Next select 2nd photo and paste as right. Be sure to start 3d-switch (on), click preview in depthcharge. Now you'll see red-blue anaglyph. WITHOUT the red-blue cardboard glasses look at photo. You can see the stereo separation much more easily in red-blue mode. about 1/2" to 1/4" seems to be the best. If any more your brain will turn to jelly trying to merge the photos, any less and the 3d effect goes away. If the distance seems ok, right click and change to 'vrex pro products' viewing method (yellow light should be on transmitter on top of your monitor).
The equipment: I mount a digital camera on a tripod. I've been using Sony PC-10 in photo mode for low light stills, and digital cameras. To obtain accurate parallax, I mount a Velbon geard macro-slider. It has huge round steel rails to increase stability. I mark off in MM scale directly on front rail with permanent marker (still wears off eventually). Turn it sideways on tripod. Mark off the distance between your eyes (2.25" approx) as max on rail. It fits between tripod and camera and has a quick release on top. About $99. Tighten it down a bit with the knob (it wasn't designed for 3d work, but works great.).
Taking the pix: For the left picture even the slide and slide base right side before taking 1st pic. Now, without changing ANY zoom or other settings move the camera the parallax distance by moving the velbon slide using the gear knob Mark the slide with a permanent marker in mm/cm. For close ups you'll need to experiment. If you can zoom in to something close and make it fill up screen, 1 to 5 mm seems to work. take multiple shots at various distances. Avoid moving the camera up or down as this ruins shot.
The parallax distance: I sometimes take a series of upto 5 shots, especially if the subject moved or the camera moved. Using a fibonacci sequence of distances (increasing distances always larger than the previous parallax, added to the last slide position) or simply several shots with the same gap if something moved. If you take several shots 2mm appart, you can try merging shots that are 0+2, 0+4 or 0+6 mm apart if evenly spaced, and decide which looks best with your glasses.
For infinity focus, the parallax is much greater. Estimate the distance and take a range of pix covering the possible gaps. Keep increasing the distance (approx doubling) and add this to last slide position. E.g. 1st=0, 2nd =2, 3rd=6 (double last position of 2 and add to 2=6) 4th=14 (6+(2*4)) This way you can combine either 1st and last or any between with the least # shots up to max parallax. There is probably an equation that relates effective zoom distance to the subject in focus to the parallax distance you move the slide. As you zoom in, imaging arrows eminating from your eyes that merge on the item in focus. If you are way zoomed in (closer to the subject) these lines are much closer together (the parallax distance). 3d pix will never be perfect since your eyes move right and left independantly (merging together to focus on same spot) from a fixed distance to focus while the camera moves only right and left while focused straight ahead when moved as described here. Still the results can be striking. Your brain manages to combine the pictures and make 3d sense out of alot of it anyway despite the differences.
Alot of the time you do not realize you have moved the camera up or down, etc. Taking a few extra pix means you can get a good picture if one of the pix is off parallax.