To create the illusion of depth, the IMAX 3D process uses separate camera lenses to represent the left and right eyes. The two lenses are separated by an interocular distance of 64 mm (2.5 in), the average distance between a human's eyes. Each lens feeds a separate roll of film. By projecting the two films simultaneously, viewers experience seeing a 3D image on a 2D screen. The IMAX 3D camera weighs over 113 kg (250 lb).
One method of creating the 3D illusion involves polarizing the light from the two images. During projection, the left and right eye images are linearly polarized as they are projected. Eyeglasses with right and left lenses polarized to match the projection present each eye with just the image intended for that eye since the polarization cancels out the other eye's image.
Alternatively the two projectors take turns displaying each frame (while one projector's image is displayed, the other is blocked) at an effective rate of 48 frames per second. The viewer dons LCD shutter glasses that contain LCD panels that block or transmit light in each eye in sync with the projector, such that each eye only sees the image intended for it.
Several films produced in digital 3D for release in conventional theatres have also been presented in IMAX 3D, including Avatar.