Canon EF 70-300 mm F4.5-5.6 DO IS USM lens experiences.

[Jose]

I have this lens for more than a year now and bought it for its zoom range , compactness and the diffractive optics, first in a zoom lens. I do have the 100-400 mm IS Canon too so this lens was to be for light travel along with the 16-35 mm Canon; I carry one mounted in the lens and the other in a pocket. Overall the lens fullfills its role as an "urban" lens because of characterists mentioned above makes it easy to use. I call it a "stay at home lens" since when when doing serious photography it stays behind. It can be used with extension tubes with accepatable results but will not accept tele-extenders.

There are challanges with the zoom mechanism; it is fine as long as the lens is parallel to the ground but zooming with the lens pointing up is extremely stiff and if the lens is pointed down, it will extend out completely hence the locking zoom lens button (the zooming mechanism in the 28-135 IS Canon is better since it easier to zoom when pointing up). As long as the subjects are taken frontlighted the images are fine but may require some Photoshop treatment; but even then some unexplained artifacts (internal reflections, glare, etc) occur. In the plus side is solidly built and the autofocus is outstanding. I risk to predict that Canon will release an upgraded DO zoom lens to replace this one.

The image below was backlighted. It was shot with an EOS 1 Ds MK2 set at ISO 200 and the lens at 1/320, F 8 at 220 mm. The exposure was reduced and the contrast enhanced to better show the artifacts. The arrows point to larger circles perhaps the results of internal reflections, and the line in the upper corner crosses the rings resulting from the concentric circles that gives the diffractive lenses its optical characteristics. Vignetting is noticeable even at f 8 which is usually controlled at this aperture by most other Canon non-DO lenses. Some flare is visible too.