Pentax-M series bellows are old equipment from the 1970s that is beautifully crafted and still gives excellent performance almost 50 years later.

In photography, a bellows is the accordion-like, pleated, expandable part of a camera, usually a large or medium-format camera, that allows the lens to be moved with respect to the focal plane for focusing. Bellows are also used on enlargers. The below provides a flexible, dark extension between the film plane and the lens.

In some cameras, the photographer can change the angle of the film plate with respect to the optical axis of the lens, modifying perspective distortion and the object plane of focus. Bellows may be part of a camera or an optional accessory.