Well, 3-D Photography, like anything else, is not all that simple ... or is it?
The biggest issue is identical (almost) photographs taken from twin vantage points. In concept, you need to have two properly positioned and identical light paths to make it look correct. Typically, two identical lenses (aperture and focal length) focused to two sensors. Yeah ... typically. :p
... or do you?
Check this out, if you are ... creative ... and somewhat "good" with your digits.
DYI 3-D Shooter