02-21-2014, 03:36 PM
Hi everyone,
what about the testing of the edges?
Focussing with the center AF-field on a distant object (approx. 100m) in maximum
wide angle setting and ma. aperture, then switching to MF and comparing how much the four edges
are out of focus in relation to each other (not absolutely).
How ist the accuracy and importance of this test compared to the "5° checkerboard" test?
- Frank
Edit 2 March 2014: I was able to exchange the lens. In fact I got two successive replacements. The checkerboard test was ok with both, however both showed unevenly sharp edges at wide setting. I kept the 2nd replacement, because I noticed the problem was a slightly inclined field, with could easily be compensated by a minimal refocussing or inclination of the camera and is almost not relevant in real world situations.
However, sad enough, I had three XF 18-55 and not one of them was ok in both tests.
By the way, my newly acquired XF 35 mm performs fine with both tests.
what about the testing of the edges?
Focussing with the center AF-field on a distant object (approx. 100m) in maximum
wide angle setting and ma. aperture, then switching to MF and comparing how much the four edges
are out of focus in relation to each other (not absolutely).
How ist the accuracy and importance of this test compared to the "5° checkerboard" test?
- Frank
Edit 2 March 2014: I was able to exchange the lens. In fact I got two successive replacements. The checkerboard test was ok with both, however both showed unevenly sharp edges at wide setting. I kept the 2nd replacement, because I noticed the problem was a slightly inclined field, with could easily be compensated by a minimal refocussing or inclination of the camera and is almost not relevant in real world situations.
However, sad enough, I had three XF 18-55 and not one of them was ok in both tests.
By the way, my newly acquired XF 35 mm performs fine with both tests.