Testing the M 50 f1.7

I know most people already have this lens but it might prove interesting to somebody.

A few years ago I picked a Pentax-m 50mm f1.7 on eBay but have sadly neglected it, tonight I decided I'd test just how sharp it was so I could start using it as a portrait lens, heres my result:

f1.7

F1.7 by Paul Cliff, on Flickr

f2.8

F2.8 by Paul Cliff, on Flickr

f5.6

F5.6 by Paul Cliff, on Flickr

f8

F8 by Paul Cliff, on Flickr

f2.8 looks great, much sharper than I thought it would be, f1.7 is even pretty good but there is an odd haze around the edge of the red thing (It's a red nose I think).

Any comments/observations?

Paul.

At 1.7 the eyes are in focus but the ears and the left and right edges of the object are outside the DOF.

On the right hand edge you can make out that it is OOF and blurry and looks normal. On the left hand side you have the same OOF/blurry effect, but a blurred dark line is also apparent.

Look behind the object , you have a black broom handle or something leaning up against the wall. That is your problem.

It's a lamp, you're right, that's what's causing the dark blurry line.

I'll have to try some portraits with the family, I think I'll set up a test to see how it compares to my Sigma 17-50 f2.8 also.