Despite the large maximum aperture, the lens remains compact. Lens group 5 moves for rear focusing, and sharp, crisp pictures are obtained at all apertures. The background blur is ideal for portraits. The USM auto-focuses the lens quickly and quietly.

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Reviews

Canon 100mm f/2 review by KenRockwell.com

• The Canon 100mm f/2 is fantastic. It’s among Canon’s sharpest lenses and feels great in-hand.
• Autofocus is super-fast and quiet.
• Just grab the focus ring at any time if you want manual-focus override.
• AF is fast, as Canons always are.
• The AF motor is silent. All you’ll hear is some internal sliding.
• Bokeh, the quality of out-of-focus areas as opposed to the degree of defocus, is nothing special. Backgrounds are way out-of-focus at f/2, however their character (bokeh) isn’t all that smooth. Bokeh is reasonably so-so at f/2, and neutral at smaller apertures. At larger apertures, bokeh takes on more of an organic feel, almost like lenses from the 1950s.
• As expected, the Canon 100mm f/2 has no obvious coma.
• The Canon 100mm f/2 USM has no visible distortion.

Canon EF 100mm f/2.0 USM Lens Review by the-digital-picture.com

The Canon EF 100mm f/2.0 USM Lens – meet the Canon EF 85mm f/1.8 USM Lens’ twin sibling. Put these two lenses side by side and you will need to read the numbers to tell them apart. That is a good thing.
The Canon EF 100mm f/2.0 USM Lens shares the Canon EF 85mm f/1.8 USM Lens’ solid build quality. This is a noticeable step up from the Canon EF 50mm f/1.4 USM Lens’ construction. Everything feels solid. Very nice.

Canon EF 100mm f/2.0 USM by photo.net

I bought my Canon EF 100mm f/2 USM lens in 1996 because I needed a fast lens for concert work; I couldn’t afford any of the “L” series zooms. Years later, as I look over the images it’s produced, I can say that it’s one of the finest lenses I’ve ever used.

Comparison Review of Canon EF 85mm f/1.8, Canon EF 100mm f/2 and Canon EF 135mm f/2 L Lenses by wlcastleman.com

This is the third edition of a review comparing three superb Canon short telephoto lenses used for portrait and action photography. I initially reviewed the performance of the Canon EF 100mm f/2 relative to the Canon EF 85 f/1.8 and EF 135 f/2L lenses in 2001 because I was photographing sports and dance under available light where I have to shoot from a fixed location at f/2. There are times when the 85 is too wide and the 135 is too narrow to fill the frame with the subject. I was interested in comparing sharpness (resolution) of the lenses at f/2 and background blur in out-of-focus areas (bokeh). I subsequently have reviewed the lenses comparing their performance in portrait applications. The latest update provides performance information from newer digital cameras as of September, 2007.