Jupiter 50mm/1.5 user report

[pgs@pa.dec.com (Patrick Sobalvarro)]

So, I've had a chance to use this ex-Soviet lens now and see some of
the results.  The film was Ilford XP2, so the inherent resolution of
the negatives is not very high.  I made almost all exposures wide open
at f1.5 -- perhaps for a couple I stopped down to f2.

The most immediately obvious quality of the lens is that, at the
apertures where I used it, it suffers from very marked coma.  Bright
off-axis out-of-focus highlights (like Christmas tree lights) are
smeared in an arc about the center of the image.  I don't find this
terribly unpleasant (I like it better than mirror-lens donuts, for
example), but it's quite noticeable -- Christmas tree lights become
triangular. 

The centers of the images are quite sharp, when I focused the camera
properly.  These were quick shots of friends, where I had
scale-focused the camera first and then raised it to my eye, made a
quick attempt to focus, and shot in a couple of seconds.  It was
indoors under available light at night, and at f1.5 and close up there
isn't much depth of field, so a number of the close shots were out of
focus.

I don't notice any flare, even where there are bright lights shining
into the lens.

Sharpness at the edges of the images may be quite a bit worse than at
the centers.  I can't tell very well, because the lens was wide open
and I wasn't focusing on things at the edges.

I'm going to try using it with some Kodachrome 25 outdoors in
daylight, where I can vary the aperture and use infinity focus and so
on.

- -Patrick