Bellows (photography)
From Wikipedia, the free encyclopedia
In photography, a bellows is the accordion-like, pleated expandable part of a camera, usually a large or medium format camera, to allow the lens to be moved with respect to the focal plane for focusing. Bellows are also used on enlargers. The bellows provides a flexible, dark extension between the film plane and the lens.
French inventor Joseph Nicéphore Niépce was one of the first to apply the bellows to photographic instruments.[1]
Classification
Two kinds of bellows are commonly used on cameras; bag bellows are normally used with a lens of short focal length, and accordion bellows with a much longer range of extension.
For large format cameras, “double extension” refers to bellows that extend to a length equal to about twice the focal length of a standard lens, e.g. 300 mm for the 4×5 inch format. “Triple extension” for the same format indicates bellows extension of 450 to 500 mm.[citation needed]
