Gunzorro Offline Upload & Sell: On
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kevindar wrote:
I redid the test. the 24 tse was definitely front focused a bit. I am finding it difficult to get perfect focus with it, as it consistently beats the 24-70Ii in the near corners, but looses in the far corners.
the 24-70II is truly an exceptional lens. I would say, bottom line at 24mm, if you dont need tilt shift (big if) the 24-70II is simply exceptional.
I also found that with critical focus, the 16-35 F4 matches the 24-70 at f8 in the entire frame, and actually beats it at 35mm. the 24-70 F4 IS, seems to parform slightly better at 35 in the corners than its more expensive brother, but this is all splitting hair.
I was also surprised, despite what you would think is a very large dof at f8 and 24 mm, variations in focus still make a difference. ...Show more →
Kevin -- Thanks again for your comparison tests.
And, yes, I totally agree (having done a few comparisons myself) that critical focus is, well . . . critical! Ha-ha! I know it sounds trite, but it is really hard to achieve perfect focus, especially in field conditions -- even using LV at 10X.
I found for broader results, cross checks between cameras is a useful approach to get a better read on when you are dealing with lens aberrations vs. focus errors (human, or camera). I've got a Manfrotto dual camera plate where I can mount two bodies (5D2 and 1Ds3), and switch the lenses between, giving a added cross-check to the lens and the LV focusing. It's a lot of fiddling, but running the full aperture range (to f/16) on numerous subjects/scenes gives pretty revealing results.
These comparisons have had a practical result that has improved my photography. Like you, several times I've found lenses that were out of whack (notably 16-35II) and not equal on corners or sides and sent off to Canon for proper adjustment. It's sometimes hard to catch otherwise, shooting at f/11 a lot of the time, you don't realize what you are missing even at that small aperture.
Anyhow, one comparison is good, two is better, 20 is better still!
I really appreciate you and Jim providing these results. I wish I had some of these newer lenses to test (especially 16-35 IS and 24-70II). Maybe a call to CPS will be in my future to try the 16-35 IS, once the initial demand subsides.
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