Focal length: 35mm
Mount: Contax rf
Aperture: F 2.8 - F 22
Min focus distance: 0.9m
Length (see*): 38/40mm,
including the adapter, lens protrudes 10mm from the adapter rim (see
the end of the page)
Diameter: 56mm
Weight: 115gr.
*Contax
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. This one uses the outer mount.
Some pictures:
A7 and the lens.
This is a second, earlier version of the same lens. It reads JUPITER-12
1:2.8 F=3.5cm.
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 2.8.
F 8.
F 22.
Closest focus is 80cm from
outermost
edge of the lens, F 8. Focus on
the program wheel of the camera.
In my opinion this lens is a deception for full format
digital. As far
as I remember the M39 variant delivered quite good results on film with
a Bessa L.
It's based on the famous Biogon design; there are good evaluations on
the web that I can't confirm. It is soft wide open. Closed
down it's better in the center, but there is flare at the edges, see
the lower left corner. Maybe the design isn't good for full format
digital, just as the old 15mm Heliar. I own another Contax mount
and M39 variant of these, they have the same problems. The
lens has no
close focussing capablities. However it is small and lightweight.
The
Contax rf mount adapter is difficult to find and sometimes expensive,
but Contax mount lenses are often much cheaper than their M39 versions.
These 2 lenses were 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.
As
this lens has an enormous protruding rear element with an unprocted
glass, it has to
be handled with care. The A7 has just, but just enough room inside for
my version of the lens, check yours at your own risk. For security
reasons set the lens to closest focus while attaching it,
which shifts the back part inside for 2mm, at least it does on my
versions, there are people who claim the opposite. Anyway, it still
sticks out of the
adapter's outer rim. So if you want to use it on another model of
camera, please
check. There is not enough room for it in the A5000. If you don't have
the special rear cap: an empty transparent plastic film container from
35mm
film cut to half the hight will perfectly stick and protect the back of
the
lens.
