Help me decide--should I exchange this Sony 24-70 f 2.8 GM II?
p.1 #1Help me decide--should I exchange this Sony 24-70 f 2.8 GM II?
Just received this lens from B&H. Very well packed. The right side seems softer especially at 24mm. I may use it for astro and want it as good as possible wide open at f2.8. These are 200% crops so I am not sure what is reasonable. The 70 mm corners look decent with a more subtle but discernable asymmetry.
https://www.olyendomike.com/Sony-24-70-F28-GM-II-centering
Any comments appreciated.
https://www.olyendomike.com/Sony-24-70-F28-GM-II-centering
Any comments appreciated.
Jun 12, 2026 at 02:19 PM
p.1 #2Help me decide--should I exchange this Sony 24-70 f 2.8 GM II?
It’s reasonable to expect a sharp lens. Exchange until you are satisfied.
Jun 12, 2026 at 02:25 PM
p.1 #3Help me decide--should I exchange this Sony 24-70 f 2.8 GM II?
Not the worst asymmetry I've seen in a standard zoom, but certainly not the best*. I see these were on an a7r III, so it'll likely look even worse on a higher MP body. At $2,400 I wouldn't accept it.
*I'm assuming the focus was established in the center, then reframed. Assuming the subject distance is far enough to avoid DOF issues from reframing, and that your a7r III's mount isn't the issue.
*I'm assuming the focus was established in the center, then reframed. Assuming the subject distance is far enough to avoid DOF issues from reframing, and that your a7r III's mount isn't the issue.
Jun 12, 2026 at 02:32 PM
p.1 #4Help me decide--should I exchange this Sony 24-70 f 2.8 GM II?
Yes, focus established in the center. Certainly far enough away at 24mm. Thank you for thinking about this. I expected a bit better for the price. My Sigma 14-24 was more even. I'll assume the mount is OK, but a good point. I greatly appreciate other eyes looking at this.
Jun 12, 2026 at 02:58 PM
p.1 #5Help me decide--should I exchange this Sony 24-70 f 2.8 GM II?
Here's a test I just did on my Sigma 24-70 f/2.8 L-Mount @ 24mm f/2.8. This is on the Panasonic S1R, which has just slightly more resolution than your a7r III. Note this at the very extreme corners of the frame, ie where the trees are above the chimney in your shots.
https://tinyurl.com/2s3zp223
Looks similar to yours. Except this lens cost me $700 used
https://tinyurl.com/2s3zp223
Looks similar to yours. Except this lens cost me $700 used
Jun 12, 2026 at 03:45 PM
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p.1 #6Help me decide--should I exchange this Sony 24-70 f 2.8 GM II?
One thing about B&H--they don't fuss. Yours is a bit better and MUCH less dosh.
Jun 12, 2026 at 04:20 PM
p.1 #7Help me decide--should I exchange this Sony 24-70 f 2.8 GM II?
People are going to have different standards about what is acceptable. I just scrutinized each image, and for me that would be acceptable - keep in mind that viewing at 200% is equivalent to a GIGANTIC print that few on this forum have ever even dreamed of printing. Over the last four decades I have had zooms that were way worse.
YMMV
YMMV
Jun 12, 2026 at 04:36 PM
RoamingScott
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p.1 #8Help me decide--should I exchange this Sony 24-70 f 2.8 GM II?
I get almost nothing from the crooked-angle tests that so many of y'all do.
Find a nice straight brick wall and shoot it flat field at every single aperture.
Find a nice straight brick wall and shoot it flat field at every single aperture.
Jun 12, 2026 at 04:37 PM
p.1 #9Help me decide--should I exchange this Sony 24-70 f 2.8 GM II?
For that $$ I'd expect better. Try another.
Jun 13, 2026 at 01:44 PM
p.1 #10Help me decide--should I exchange this Sony 24-70 f 2.8 GM II?
While at first glance it appears you are correct, there's a simpler and more accurate way to check rough edge-to-edge sharpness for non-stabilized lenses. Just focus in the corner with AF-S, take a picture, then flip the camera upside down and repeat the process while keeping the same framing (make sure to move the focus point). You can also use the Pitch/Roll balance lines to get an even closer framing.The camera knows its upside down and will reorient a JPG/HEIF file properly. So when you compare each picture, the framing will be almost the same, and the focus point will have also stayed in the same point in the frame.
This does not work as well with optical stabilization, since the internal stabilized optics float and don't always rest in the same position right-side vs upside down.
This does not work as well with optical stabilization, since the internal stabilized optics float and don't always rest in the same position right-side vs upside down.
Jun 13, 2026 at 02:36 PM