This lens does hardly cover full format, it was built for 24x24mm
Focal length: 37.5mm
Mount: Robot M26
Aperture: F 3.5 - F 16
Min focus distance: 0.45m
Length (from flange): 17/20mm [+ 13mm for 2 adapters]
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 infinity (except
closest focus). These pictures are hand-held out of the window of my
holiday home on a dull day, so there might be blur by shake, especially at F16.
Closest focus (F8) is only 39cm from
edge of the lens. Focus on
the program wheel of the camera.
lens does hardly cover full format, it was built for the 24x24mm square
format of the Robot cameras. The adaption to the A7 is easy, the focal
flange distance of the Robots is 31mm. That's not far from the M39 which
is 28.8mm. So you add a 2.2mm adapter to a M39 one and you are there.
M26 to M39 adapters a readily available on the web and they can be
cheap. The Robot lenses are relatively small and they are fine for
This lens is very small
indeed and has a multi-blade iris, perfectly round. It has click-stops
for distance settings. According
to the serial number, this is a very old lens, made in late 1941. As
you can see on the sample pictures, there is vignetting and softness
towards the edges in full format, not visible on the 24x24mm Robot
cameras. As on many very old lenses contrast isn't terrible. The Robot
is built for hyperfocal use, so this lens is perfectly designed: it's
sharpest at F 8. The lens has very good close focussing capabilities.