Sigma 50mm f/1.4 AF issues - Fixable?

[neuroanatomist]

Seems like the [url="http://www.lensrentals.com/rent/sigma-50mm-f1.4-hsm/for-canon]comments by Roger at lensrentals.com[/url] might be relevant:


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Roger&rsquo;s take[/b]Its become apparent through many tests and online forums that the Sigma 50 is a &lsquo;special&rsquo; lens. I was glad to find this out because it was driving me nuts. Its a very nice lens when you use it just right, with superb sharpness and smooth bokeh. But here&rsquo;s the summary:


1) It works very well on crop frame cameras and at middle (5 to 15 feet) distance, so its a wonderful indoor lens.
2) On full frame cameras and to a slight extent on crop frame cameras the lens exhibits what I will term &lsquo;schizophrenic autofocus&rsquo;: Closer than 5 feet it will front focus, further than 20 feet it will backfocus. This is not a calibration issue, its just how it is.

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[JohnGoose]

Thanks for the link. I can see I'm not alone. But unfortunately, that's not encouraging news.


Despite this, the question remains, can Sigma service address this issue?


Is there anyone out there who has had 1st hand experience with this "glitch" and sent their lens in for service??