Linda From Maine wrote:
None of these appear to be in focus. Perhaps the
lighter weight of the smaller lens is causing you to
move the camera as you depress the button? 'Cause
I see super-sharp images with your 100-400 .......
The 18-35 range puzzles me. I have an old sigma
that is 19-35, so I don't know how similar, or not,
my experience is. My experience is that the lens
is quite capable image-wise, but not to be trusted
AF-wise due to mechanical backlash.
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Seems like many old AF lenses were built rather
loosely [all brands incl OEM] to let them move a
bit faster. This is not great for accuracy but having
participated in the initial migration to AF I can say
that at the time we were all habituated to MF, and
more or less knew that AF was better reserved for
hurried work at mid-to-smaller stops. IOW, we all
knew how far to trust the AF lenses of that era.
But now, a few oldies still in circulation get in the
hands of the "AF generation" who were born into
a time of reliable, accurate AF lenses, and today's
users might not realize the limits of the AF oldies.
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