INDUSTAR-22  1:3.5 F=50mm

This lens is collapsible.

Focal length: 50mm
Mount: M39, but have a look at the last paragraph
Aperture: F 3.5 - F 16
Min focus distance: 1.20m
Length (from flange): 13/37mm [+ 11mm for the adapter],
tube protrudes 18mm to the back when collapsed
Diameter: 48mm (base)
Weight: 100gr.

Some pictures:

A7 and the lens, collapsed

A7 and the lens, extended.

Sample pictures: You may click on the sample image (except closest focus) for full resolution. The full resolution image opens in a new window, so you can keep it open for comparison. Focus is on the satellite dish to the right of the big solar panel near the center of the photo.

F 3.5.

F 8.

F 16.

Closest focus  is 1m (!) from outermost edge of the lens, F 8. Focus on the program wheel of the camera.

The Industar-22 was made by KMZ and is a Zeiss Tessar formula, 4 elements in 3 groups. Elements 3 and 4 are cemented. It's said that it was copied from the Leitz Elmar, which is the Zeiss design. It had a predecessor, the Industar-10. As the Industar-10 was later produced and improved by FED, production dates overlap. Late 10/FED and the 22 are similar.

Already wide open picture quality is o.k. Stopped down it's astonishing for such a simple lens design. Have a look at the full resolution image at F 16 and you know what I mean. The lens has no close focussing capablities. It is very small, lightweight and cheap. A very nice legacy lens to start with.

This lens is collapsible. There is enough room iside the A7 to collapse it, at least with my version, but you have to try at your own risk. Please proceed slowly, you don't want to aspire dust into the camera. It's an extremely small and lightweight lens. Depending on your adapter, you might have to cut out a little "groove" for the base of the tiny knob, that has to be pushed in  to set the lens to infinity and lock it there. My adapter has a slightly protruding ring, so I had just to file off a weeny bit of the base of the knob. Some Industar-10 and the FED lenses
have a clip lock for infinity, not a push-button, as the Industar-22. Depending on your adapter, the push button can be a problem, so a late Industar-10/FED might be preferable to a 22.

The lens can not be fully collapsed into the A6000. It touches the plastic around the opening for the sensor. If you push cautiously, it collapses quite a bit, but again it's at your risk.