[seppstefano]

Thanks for answering!

Isn't lp/mm a measure of resolution rather than of contrast anyway, or am I missing something?

Best of all it would be nice to find MTF test for K and M mount lenses.

[lytrytyr]

Isn't lp/mm a measure of resolution rather than of contrast anyway, or am I missing something?

Line pairs per millimeter, as a spatial frequency,
is one of the coordinates for measurement, the other being contrast.
So a good lens may deliver a contrast of 50%
at a spatial frequency of 40 lp/mm
(at a certain part of the image field,
for a certain color of light,
when focused at a certain distance,
in a certain orientation, . . . It's complicated!)

Best of all it would be nice to find MTF test for K and M mount lenses.

I included Pentax' charts in my December 19, 2011 review of the M100/2.8:
SMC Pentax-M 100mm F2.8 Reviews - M Prime Lenses - Pentax Lens Reviews & Lens Database

Photozone did a test on the K135/2.5:
Pentax SMC-K 135mm f/2.5 - Review / Lab Test Report - Analysis

You may find some others scattered in cyberspace.

[seppstefano]

I included Pentax' charts in my December 19, 2011 review of the M100/2.8:
SMC Pentax-M 100mm F2.8 Reviews - M Prime Lenses - Pentax Lens Reviews & Lens Database

Photozone did a test on the K135/2.5:
Pentax SMC-K 135mm f/2.5 - Review / Lab Test Report - Analysis

You may find some others scattered in cyberspace.

Fine

thanks a lot for sharing these links.

Stefano

[oxidized]

I have not had K or M 50 1.4, but from what i've heard it is supposed to be better. i have the 8 element 50mm 1.4 and it is sharper at 1.4 than my 50A 1.7. It is VERY sharp! I hear the non SMC 7 element version is not as sharp but the SMC 7 element ones are also very sharp. THe only downfall of the 8 element version is that it is VERY prone to flare if you dont use a hood.

[seppstefano]

This may be a couple of interesting links, too.

test_zeiss50

http://forum.mflenses.com/viewtopic.php?t=13521