The Canon EF 70-300 DO IS USM is Canon's second offering in the DO (diffractive optics) lineup. The 400 mm f/4 was first introduced a few years ago with the promise of longer focal lengths combined with lighter weight. The EF 70 - 300 DO IS USM is the first "affordable" lens from Canon using the new technology.
The 70 - 300 is built very well. Unlike Canon's "L" lenses, the 70 -300 DO carries a green ring designating it's "DO" lineage. The lens comes with a lens hood and carrying pouch. When dialing in a longer focal length, the lens protrudes as focal length increases. Also added is a "zoon ring lock" which prevents accidental extension of the lens. There are two modes for IS (image stabilization), mode 1 for static objects, and mode 2 for panning. All in all, the lens is built extremely well, and carries a lot of features not present on other consumer lenses.
Operation and Image
Immediately noticable is the light weight. Particularly if you're used to shooting with Canon L lenses, the 70-300 DO will seem light as a feather at it's weight of only 720g/25.2 oz. For travel purposes or when otherwise traveling light, the 70 - 300 provides very useful focal lengths in a very manageable package. This however is not enough for serious photographers if image quality is sacrificed to a great degree. I had the opportunity to shoot with the 70 - 300 DO for two days. The first day was shooting an outdoor concert. I was very pleased with the contrast and skin tones of the lens. Zoom operation was very smooth, and autofocus was acceptable, though not as quick as Canon's 70 - 200 2.8.
Very acceptable results. Obviously at 4.5 - 5.6, the 70 - 300 DO is not made for low light concert photography, but in good light, the lens puts out a very pleasing image. The above shots were shot wide open. The three shots below demonstrate the performance stopped down to f/16.
I don't have the necessary equipment, nor the expertise to fully technically analyze this or any other lens. I can only make my judgements on whether or not a piece of gear operates the way I want it to, and creates images I like. The 70 - 300 doesn't compete with primes in image quality. It's not quite as good as the 70-200 (however you do gain an extra 100mm in focal length). For photographers wanting to minimize travel weight, the sacrifices of the 70 - 300 DO should be acceptable to most. For those with very demanding requirements, you'll still be carrying your usual payload of lenses. Check out the full gallery of 70 - 300 DO shots here.