Here is a challenging test for any zoom. These are wide open (f2.8) extreme corner comparisons (approx the last 5% of the frame) across the full zoom range, tested at 14mm, 20mm and 24mm. Focus was held fixed at each focal length. A distant aerial on a roof top was moved in turn into each extreme corner without adjusting focus. Apologies for the somewhat variable lighting across some of the frames.
As usual, 100% crops from 42mp, minimal sharpening.
*** Edit ***
Here is another go at assessing centering of my copy at 24mm in some better light, and focused slightly further out. Maybe it's a little better than than indicated by the last test, and maybe for a zoom it's not bad. If you have this lens, and care to assess centeredness at the long end in particular, please feel free to share your findings.P.s. I find it better to focus so at least one corner is sharp rather than center-focus as field curvature can otehrwise mean none of your corners are very sharp.
Here is a challenging test for any zoom. These are wide open (f2.8) extreme corner comparisons (approx the last 5% of the frame) across the full zoom range, tested at 14mm, 20mm and 24mm. Focus was held fixed at each focal length. A distant aerial on a roof top was moved in turn into each extreme corner without adjusting focus. Apologies for the somewhat variable lighting across some of the frames.
As usual, 100% crops from 42mp, minimal sharpening.
*** Edit ***
Here is another go at assessing centering of my copy at 24mm in some better light, and focused slightly further out. Maybe it's a little better than than indicated by the last test, and maybe for a zoom it's not bad. If you have this lens, and care to assess centeredness at the long end in particular, please feel free to share your findings.P.s. I find it better to focus so at least one corner is sharp rather than center-focus as field curvature can otehrwise mean none of your corners are very sharp.
Here is a challenging test for any zoom. These are wide open (f2.8) extreme corner comparisons (approx the last 5% of the frame) across the full zoom range, tested at 14mm, 20mm and 24mm. Focus was held fixed at each focal length. A distant aerial on a roof top was moved in turn into each extreme corner without adjusting focus. Apologies for the somewhat variable lighting across some of the frames.
As usual, 100% crops from 42mp, minimal sharpening.
Here is a challenging test for any zoom. These are wide open (f2.8) extreme corner comparisons (approx the last 5% of the frame) across the full zoom range, tested at 14mm, 20mm and 24mm. Focus was held fixed at each focal length. A distant aerial on a roof top was moved in turn into each extreme corner without adjusting focus. Apologies for the somewhat variable lighting across some of the frames.
Aug 20, 2019 at 10:38 PM
Previous versions of rvh23's message #14952289 « Sigma 14-24mm f/2.8 DG DN first impressions »
