Here two or more very different pictures are used, and the lenses are designed to require a relatively large change in angle of view to switch from one image to another. This allows viewers to easily see the original images, since small movements cause no change. Larger movement of the viewer or the print causes the image to flip from one image to another. (The "flip effect".) An example of this is the lenticular print for the movie Ghost Rider.
Stereoscopic Effects (3D)
Here the change in viewing angle needed to change images is small, so that each eye sees a slightly different view. This creates a 3D effect without requiring special glasses, using two or more images. An example is 2001: A Space Odyssey.
There are two main materials used for lenticular lenses.
The first is called PET (Polyethylene terephthalate) and is around 1mm in thickness. This lens can be mounted on either paper or plastic backing. This material is best for transforming effects, but can also be used for 3D effects.
The second is called PS (Polystyrene). It has a thickness of 4mm and resembles plexiglass. This is best used for strong 3D effects.
Due to the nature of the Lenticular lens and in order to get the best effect, it is recommended to view Lenticular prints from about 4 to 6 feet away.
The only way to visualize how a lenticular print will look is with the use of a .GIF digital image. This allows the viewer to understand the desired effect, whether it is a 3D or flip effect. In person, the Lenticular print will be much smoother for flip effects and have a much stronger and clearer 3D effect.