How 3D works If you don't know how 3D photography works, here is a brief summary: Objects look solid and 3D to us because we have two eyes, separated by a few centimeters, that see things from different points of view. The brain interprets these different images and creates a 3D illusion from them. The problem for photographers is to somehow get two separate images to two different eyes without interference using a 2D medium. ViewMaster The GAF ViewMaster and other such systems use a viewer with two lenses each of which view a separated image on a circular reel. The principle has been around since the 19th century and gives great results for still photographs but is no good for the cinema. Reels are still manufactured and original ViewMaster machines are valuable. Anaglyph The classic red/blue glasses method, great for those black and white movies of the 1950s. Red and cyan may be used for projection and for viewing. One colour image for each eye. Can be used for 3D and also for showing two different images, as Jack did on his Jackyll and Hyde picture. Not so great for colour images but it works, kind of. Polarised glasses Polarised glasses have relatively clear and uncoloured lenses. Each eye lets light with a different orientation through. The advantage of this method is that it works well for colour images, viewed without the glasses the image is acceptable too, but obviously it won't work for printed pictures, tv or computer screens. Used a good deal for recent films. Pulfrich This system uses glasses featuring a dark lens and a clear lens. It's a curiosity of the human system that images seen through the clear lens reach the brain slightly faster than images seen through the dark lens. With properly sequenced movement recorded on film or video, objects moving across the horizontal field of vision create the illusion of 3D. This has been used on tv a lot - the give away is that there's an excess of right to left motion across the screen. Without the glasses, the image looks normal. Lenticular The image is prepared in a special way, then a lens consisting of a large number of vertical clear plastic prisms is placed over it. This technique has been around a long time, being popular in the 1950s and 60s on bubble gum cards. It is still used a lot and was famously used on the cover of a Rolling Stones LP. The image may also change as you move past it with an effect similar to that shown in the Logan's Run film. The effect seems to work better with drawings and cartoons or inanimate objects.