|Canon EF 100mm f/2 USM Specifications|
|Lens Construction (groups)||6|
|Lens Construction (elements)||8|
|No. of Diaphragm Blades||8|
|Closest Focusing Distance||0.9m (35.4")|
|Maximum Diameter x Length||73mm x 73.5mm (2.9" x 2.9")|
This small and light Canon 100mm f/2 is sharper than the sharpest zoom I've ever used: my Canon 70-200mm f/4 L IS, and it's four times as sensitive to light, letting me shoot with one-quarter the ISO or with four-times the shutter speed in the same situation.
All three of these lenses are well-constructed and light weight. They are all ultra-fast focusing and produce high contrast images. They differ in resolution, 50% MTF (microcontrast), and background blurring (bokeh) produced as outlined below.
The 100mm focal length combined with the wide aperture makes this a very good portrait lens. Selecting the length of a portrait lens is a combination of functionality and personal preference. 100mm falls in the middle of my 85mm-135mm preference for a portrait lens.