Canon quality—an oxymoron
The term “Canon quality” should be interpreted to mean “a suspect level of performance”. Of the 16 or so Canon EF lenses I’ve bought over the years, somewhere between 1/3 and 1/2 of them have had optical issues right out of the box that require an exchange (if detected early enough), or a trip to Canon service. It’s when I’ve been lax and failed to test a new lens immediately that I regret it.
Many people won’t notice such issues, because they’ll be masked by depth of field. Some readers have sent me test images at f/8 or f/11, seeing “no problems”! That’s hardly surprising, since depth of field at f/11 will mask some issues enough to make them hard to detect. But woe to the user at f/2.8 or f/4.
One must look for symmetric sharpness left-to-right and top-to-bottom (assuming appropriate subject/camera alignment). A lens shot wide open should exhibit the same degree of sharpness at the left edge/corner(s) as on the right. There are other issues too, but that is the most basic test. Stopping down hides issues, as does checking a lens on a cropped-frame camera. Zoom lenses might be fine at one focal length, and be “off” at others.
Abnormal lens—check optical performance!
I just sent in my Canon EF 50mm f/2.5 macro to Canon service because it would not focus to infinity (optical performance at closer distances seems fine). It’s about a $250 lens. Canon’s estimate to repair this lens is about $150, since it is six months or so beyond the one year warranty. I’ve used it a handful of times, and it has never been rolled, banged, dropped, bounced or even looked at crossly. So the problem had to exist from day one, which has been the case with too many Canon optics. I’m furious that Canon expects me to pay for their crappy quality control; parts inside the lens don’t just go bad on their own (the lens is in mint condition).
An exception? Hardly! My 16-35 f/2.8L had focusing problems (Canon replaced the focusing unit). My 100mm f/2.8 macro showed 3 of 4 blurry corners (it just came back and I’ll reshoot it). My 24-70 f/2.8L showed strong color fringing on one side (two trips to Canon service to fix that problem). My first 70-200 f/4L IS was soft on one side (see Brand New Blur), as was my 85mm f/1.8. My 135mm f/2L shows astigmatism in the corners (an expert friend concurs that it is abnormal).
Canon lenses are excellent designs, but quality control is abysmal and therefore real physical lenses vary widely in performance. Don’t assume anything about the performance of a brand new lens—shoot it critically, wide open, and don’t make excuses for it when you suspect a problem—verify the problem (repeat the test), then get a new copy or force Canon to fix it. A resolution chart is good, a brick wall is good, and field shots should confirm both of those. And be very wary of sellers of used lenses looking to dump their “dogs” (I simply won’t sell any lens with a problem; I get it fixed—my reputation is worth a lot more to me than one sale).
While Nikon has delivered misaligned lenses also, at least I’m not stuck paying for it; Nikon offers a five year warranty on most lenses. Canon should stand behind its products. All of which begs the question: do you avoid these issues with Zeiss ZF lenses? Stay tuned.
