Vivitar OM Auto Extension Threaded Tube AT-21 36mm 20mm 12mm - Japan + Case

Appears to Be in Good Condition. Has Not Been Used for Some Time. Worked Last Time Used. Recently Untested. Comes with Case. See Photos.  Comes w/ Case  I Usually Ship Within One Business Day of Purchase  Custom SKU: 005-12612  The Vivitar OM Auto Extension Threaded Tube AT-21 36mm 20mm 12mm is a set of 3 extension tubes designed for use w/ Olympus OM system cameras. These tubes allow you to use your existing lenses for macro photography & close-up shooting by increasing magnification. Function: Extension tubes work by extending the distance between the lens & the camera's film plane (or sensor). This extension increases the lens's magnification, allowing you to focus on subjects at closer distances than you would without the tubes. The extension tube set is a valuable tool for photographers who want to explore the world of close-up & macro photography without needing to purchase expensive macro lenses Using these tubes, you can effectively turn a regular lens into a macro lens, enabling you to take detailed photos of small objects. An extension tube has no optical elements; it simply extends the distance between the lens & the camera. The amount of magnification you gain is roughly equal to the tube's length divided by the lens's focal length. Example, a 20mm tube attached to a 50mm lens would increase the magnification by 0.4x