Bellows
A light-proof and flexible tube that can be folded into a concertina shape that is used to separate a lens from the body of a camera. The use of bellows on cameras dates back to the middle of the 19th century, and this technology is still in use on large-format equipment today. They have a swing and tilt mechanism that enables the plane of focus to be adjusted to the desired position. In order to make more finely adjusted macro photographs, bellows are often employed instead of extension rings on single-lens reflex cameras.
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