Autofocus and the Canon 7D

Much of my photographic efforts over the past six months have been devoted to curling, particularly since I became involved with the Laurier Golden Hawks High Performance Centre in November. Since then I’ve photographed a number of teams and clinics in a variety of different curling clubs.

When setting up the High Performance Centre website, I consciously chose a grayscale theme because my intent was to convert all the curling photographs to black and white. My reasoning, which I think was sound, is that black-and-white photographs would unify the various images taken at different curling clubs, and also mitigate the issues with dim, fluorescent lighting used at many of them. The fluorescent lights at the Elmira and District Curling Club give a quite noticeable colour cast that is difficult to entirely eliminate, especially if flash is used as well. The more significant issue is the lack of light – at the K-W Granite Club in Waterloo, to shoot at ISO 800 I am forced to use f/4.0 (wide-open) at 1/60 sec with my Canon 17-40L.

With the dim light, I’ve relied more often on my Canon 50mm f/1.4 prime lens, which is the sharpest lens in my bag and one I have relied upon since I purchased it a few years ago. Unfortunately, lately my experience with the 50mm lens and the 7D has let me down: the autofocus would intermittently cease to function altogether, or sometimes the lens would focus on a completely different point than what I thought.

I didn’t think I had a problem with autofocus on the 7D – with other lenses I’ve not had the same issues, though certainly when photographing action shots under dim light the hit-to-miss ratio can be fairly high. There’s also a lot of commentary on the Internet (eg. here) that seems to place the blame squarely on the 7D’s autofocus mechanism. So I upgraded the 7D’s firmware to the latest version, but it changed nothing.

Fortunately, I have several other Canon EOS film bodies. None of those cameras could autofocus with that lens either. As it turns out, apparently the Canon 50mm f/1.4 lens is notorious for being flaky with its autofocus mechanism; the lens is sharp, to be sure, but the slightest jar to the lens (even in a padded camera bag) can cause the autofocus to stop working.

Canon’s service centre in Toronto offered to repair the lens for a price – but I am reluctant to put more money into this lens, having already had it at the shop for another problem earlier. So now I have Sigma’s equivalent 47mm EX DG f/1.4, which I hope will serve just as well, purchased through BJ Photo in Waterloo. No autofocus issues thus far!

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Image above: Canon 7D with Sigma EX 70-200 f/2.8 zoom @ 160mm, 1/125 sec at f/3.5.

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