This is one terrific lens! It solves the problem of wide-angle coverage in the 1.6 FOVCF very nicely. As others have pointed out, the mechanical build and optical quality (with 3 Aspherical elements and 1 Super-UD) probably deserve an “L” stamp and a red ring. This lens appears to be of almost identical build, quality and size as the EF 17-40mm f/4.0 L USM. Even uses the same 77mm filter size as most of the L’s. Overall sharpness is excellent, with maybe a little softness towards the corners at 10mm, but I’ve seen comparisons with other ultra-wide zooms like the Sigma and the Canon blows them away! CA is well controlled too. There is slight Barrel and Pincushion distortions present at the low and high ends, but less than would be expected for a lens this wide. All in all this is one of the best wide-angle zooms available.

The major criticism of this lens usually comes down to; “well, how long will Canon continue to make 1.6 FOVCF cameras?” or “Someday I might upgrade to a Full Frame camera, then what will I do with this lens?” I doubt very seriously that Canon will do away with the APS-C cameras any time soon. My reasoning is that:

1.Canon just came out with the Full Frame 5D at the $3000 price point. Introducing a FF camera to replace the 20D at $1500 would kill the 5D after only a few months.
2.Having the EF-S lens line already established almost guarantees keeping the 1.6 format - mostly because of this lens. To be able to use the EF-S 10-22mm, a chip can’t really go any bigger than 1.6 since this seems to be the limit of the useable coverage. Using a 1.5 or 1.4 sensor for example would probably start to introduce significant fall-off at the corners of the larger chip.

As I am writing this, the PMA conference is only four days away. My prediction is that Canon will announce a replacement for the 20D that will, in essence be a 1.6 FOVCF version of the 5D. They will probably increase the (already excellent) density of the 20D’s CMOS by shrinking pixel size down to around 5 micron yielding something around the 10 mega-pixel range to compete with the Nikon D200. Maybe they will call the camera the 50D after the 5D since they can’t really use the name 30D because D30 was already used.

In any case, my point is that the 1.6 APS-C format will likely be around for some time to come, until the point where the FF price point drops enough to warrant discontinuing the xxD line. Even then, when that happens, doesn’t mean you’ll throw your 20D in the trash! You’ll still want to keep using it and/or sell it, and having this lens will significantly increase its usefulness or resale value.

Now, having said all that, this is the only EF-S lens I plan on buying. From the reviews I’ve read, the other EF-S lenses are of significantly lesser quality, and all of your other lens needs can be met with standard EF lenses anyway, APS-C or otherwise. Plus you get the option to buy L glass.

So, bottom line is buying this particular EF-S lens for a 20D or XT is a no-brainer. It’s the best solution for wide angle in this format. Hesitating to buy it because “I might get a FF camera someday” is also nonsensical. What I might do in the future is just that, for the future. Not buying a mid-priced car today because “someday” I might buy a Ferrari doesn’t satisfy my use and enjoyment of the car today!

Buy or read more reviews of Canon EF-S 10-22mm f/3.5-4.5 USM SLR Lens for EOS Digital SLRs here

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