There are basically two types of projection lenses, one is prism and the other is lens. Prism-type projection lenses are anamorphic lenses composed of one or more prisms. Due to the relatively simple physical structure, users can also create their own in addition to buying finished products, which is very convenient.
At the same time, this kind of projection lens can be made into a very large size, so the adaptability of the projector is very wide, and the aperture can also be designed to be large, which can greatly reduce the brightness loss of the projector. The disadvantage of the anamorphic projection lens is the distortion of the picture is not well controlled, and the distortion at the edge of the picture is very obvious.
Compared with the prism-type anamorphic lens in the projection lens, the anamorphic lens structure of the lens group is much more complicated. It is usually composed of multiple lenses and is realized by the refraction of light in the multiple lenses. The lens structure of a conventional digital SLR camera is basically the same, but the size is much larger. In the camera, there are usually tens of thousands of good lenses. The projection lens has an excellent image distortion control ability through the complex optical structure and the deformation of the lens group structure. This is the most important point for buyers who are pursuing perfection. At the same time, the overall image quality is better than that of a prism-type projection lens, but because the loss of the amount of light transmitted by multiple lenses is very obvious, the requirements for the brightness of the projector are very high.