Library

If you are new to S3D, start with How stereoscopy works. The geometry of shooting and viewing stereoscopic 3D: parallax, convergence, interaxial, perception and distortions. Each concept is explained with the formulas the calculator uses and with diagrams that have sliders.

Symbols

All lengths are in millimeters or meters. Parallax sign: positive behind the screen, negative in front of the screen. In most places parallax is given as a ratio of image width (percent), so the same value holds at any resolution.

Symbol	Meaning
`b`	Interaxial: the distance between the optical centers of the two lenses
`f`	Focal length
`Wc`	Sensor (image) width
`C`	Convergence distance: the distance that falls at zero parallax
`Z`	Distance of a point from the camera; `Zn` nearest, `Zf` farthest
`Ws`	Screen width
`V`	Viewing distance
`e`	Interocular distance
`P`	Screen parallax (mm); `d` as a ratio of image width
`Zp`	Perceived distance (from the viewer)
`Zs`	Distance of the main subject
`Hc`	Sensor (image) height
`N_px`	Horizontal pixel count of the image
`M`	Frame magnification: Ws / Wc
`Wconv`	Width covered by the frame at the convergence distance: C · Wc / f
`β`	Toe-in angle of each camera in a converged rig
`ρ`	Roundness: the ratio of perceived depth to perceived width
`H`	HIT: amount of horizontal image translation (ratio of image width)
`pos, neg`	Back and front limits of the comfort window (ratio of image width)
`N`	Aperture (f-number)
`′`	Arcminute: 1° = 60′

Where formulas taken from the sources keep their original letters, the page maps them separately; for example, Bercovitz's N is the nearest distance (Zn).