Help with sigma lens' focusing ring!

<p>hello!<br>

I just bought my second sigma lens, a 17-50 for nikon cameras, and I didnt know it had a focus switch (AF/M). Unlike my other sigma, 10-20, which has manual override. (minor drawback of the 17-50, lens like that should have override!)<br>

I tried to twist the focusing ring while the switch was set to AF and, although it was hard to do it, it could be moved.<br>

Later I read on the manual that I shouldnt be doing that because it might damage the AF mechanism.<br>

Do you guys think I somehow already screwed it? How can I test to see if everything is alright?</p>

<p>Try autofocussing the lens on something and see whether it works? If it was a screwdriver lens, I'd not be too worried (the motor in the camera is, as far as I know, conventional, and the worst that'll happen is putting a bit of voltage through some control wires because a motor driven backwards is a dynamo, unless you force it hard enough to strip some gears); I've accidentally done this while failing to understand how a Sigma 20mm f/1.8's clutch mechanism works, with no apparent ill effect. For an HSM lens, though, I couldn't tell you what it might have done.<br />

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I suspect that unless anything went crunch, and it appears still to autofocus you may be okay. Just don't do it again? (That said, I've just had a Sigma lens's focus mechanism fall apart, but it wasn't anything I was doing to it at the time...)</p>

<p>The lens still focus while in AF yes, I just thought there might be something small or hard to be noticed that could've happened. AF seems fine.</p>