ORION-15 6/28

Focal length: 28mm
full format, APS-C equiv. 42mm
Mount: M39
Aperture: F 6 - F 22
Min focus distance: 1m
Length (from flange): 23/26mm
[+ 11mm for the adapter], rear element protrudes 5mm
Diameter: 50mm
Weight: 60gr.

Some pictures:

A7 and the lens.

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 6.

F 11.

F 22.

Closest focus
is 85cm from outermost edge of the lens, F 11. Focus on the program wheel of the camera.

In full format digital this lens was kind of a deception. As far as I remember it delivered quite good results on film with a Bessa L. It's based on the famous Topogon design and it's slow. At max. aperture F 6 its quite good already, a bit soft at the corners. At F 8 it's just fine. 
At F 22 it only gets soft at the edges due to diffraction, which is much better than other lenses. This is a problem of the APS-C sensor size, not the lens (see comparison page). The lens has no close focussing facilities. However it is extremely small and lightweight, unfortunately it's quite expensive.