INDUSTAR-10 FED  1:3.5 F=50mm

This lens is collapsible.

Focal length: 50mm
Mount: M39
Aperture: F 3.5 - F 16
Min focus distance: 1m
Length (from flange): 10/36mm [+ 11mm for the adapter],
tube protrudes 18mm to the back when collapsed
Diameter: 48mm (base)
Weight: 112gr.

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. There is quite some dust on the sensor, I played with Lensbabies and clones which aspired dust.

F 3.5.

F 8.

F 16.

Closest focus  is ~ 0.9m from outermost edge of the lens, F 8. Focus on the program wheel of the camera.

This lens is an Industar-10 design, made by FED. It's 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. My lens is coated and has the serial number on the front. According to the number it's from the mid-1950s. It has 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 might be preferable to a 22.

Already wide open picture quality is o.k, it's a bit soft towards the edges. Stopped down it's astonishing for such an old lens and 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.

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.