Focal length: 50mm
Mount: Contax rf
Aperture: F 2.0 - F 22
Min focus distance: 0.90m
Length (see*): 23mm [+ 19/25mm for the adapter]
mount is quite different. In fact it's two mounts. The inner mount has
a focussing helical, so the standard lenses don't have one. The outer
mount is for other lenses which have their own focussing device. Its
difficult to measure. I have taken the locking pin for reference.
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
dish to the right of the big solar panel near the center of the photo.
Closest focus is 78cm from
edge of the lens, F 8. Focus on
the program wheel of the camera.
As expected, the
performance of the Contax mount lens is similar to the M39 mount lens.
Although this is an older lens which can be found for low prices, it's
decent. Wide open has some more flare than the M39 version at F
2, stopped down it's
sharp. The lens has no
close focussing capablities. It is relatively small and
lightweight, particularly for a F 2 lens. A nice lens which offers 1
usable stop more than standard.
Contax rf mount adapter is difficult to find and sometimes expensive,
but Contax mount lenses are often much cheaper than their M39 versions.
This one was very cheap and I already had the adapter. Otherwise there
is no real advantage in comparison to the M39 model
which weighs less for the combination adapter/lens.