This is an anamorphic lens used to stretch an image by factor 1.5x, usually horizontally. The usual application is to create widescreen images from non-widescreen formats. For example it can be used to create a 1:1.85 Aspect Ratio image from a 5:4 digital projector, for applications such as e-cinema.
The Cine-Digitar 1.42x lens is used to create widescreen images with digital projectors, without letterboxing. This allows the use of all the projector's resolution and brightness. 1.42x anamorphics can be used to create a 1.85 aspect ratio image with 4x3 projectors.