Minolta Auto Bellows 1 with front and rear caps and accessory Minolta focusing rail, very clean.
With an auto bellows, Minolta MC/MD mount lenses with automatic diaphragm stop down automatically when used on a manual focus Minolta (SRT, XE, XD, etc.) body and when the camera's shutter release button is pushed . Minolta did offer a short mount 100mm f4 auto bellows lens which would focus from macro to infinity. There are, of course, bellows units that are sold without the focus rail and without the auto diaphragm feature, but those aren't in the same league.
Magnification with a bellows unit is infinitely variable as opposed to extension tubes. There are videos on YouTube that may be helpful for those who are interested.
The focus rail was an optional accessory (extra cost). The distance between the lens and body sets the image magnification while the focusing rail moves the camera, bellows and lens forward or backward as a unit to focus. Many third party bellows units are sold without the focusing rail which makes them "tedious" to use. Minolta auto bellows units were a favorite with dentists because they were fast and easy to use..
The unit will accept either Minolta "short mount" bellows lenses or standard Minolta MC / MD lenses. A 100mm enlarging lens also makes a great bellows lens (with an adapter), and will focus to infinity....The Schneider Comparon was one lens suitable for enlarging, macro as well as at infinity focus and would be an inexpensive option using an adapter. (However, no auto diaphragm coupling with an enlarging lens)
Can this bellows be used on other make 35mm or digital cameras with an adapter? Maybe, but that's for you to determine. Canon made a spring loaded "auto macro adapter" that mounted just behind the lens and worked with a double cable release, one to the camera, the other to the adapter and lens. Perhaps Minolta made a similar adapter that could be combined with a Minolta to whatever mount you need.? However, it would be simplest and work best with an MC/MD Minolta mount lens.
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