Canon EF 100mm f/2.8 Macro USM lens

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Key Features
EF 100mm Macro USM

Maker:	Canon
Image Stabilisation:	No
Silent AF Motor:	Yes
Short Back Focus:	No
Macro Capable:	Yes
Unique features:	1:1 macro
Application:	Macro/portrait
Technical Data
Type:	Prime
Focal Length :	100mm
Frame Coverage:	Full Frame
Aperture (max/min):	f/2.8 - f/32
Construction:	8 groups / 12 elements
# Diaphragm blades:	8
Close focus distance:	12in / 310mm
Max. Magnification:	1:1
Physical
Max. Diameter:	3.1in / 79mm
Max. Length:	4.7in / 119mm
Weight:	1.32lbs / 600g
Filter diameter:	58mm
Accessories
Lens Hood:	ET-67
Angle of View
Diagonal:	24°
History
Introduced:	2000
Retail Info

Canon's 100/2.8 Macro USM for the EF mount replaces an earlier lens of the same specifications, but with an old-fashioned autofocus motor. The optical formula did not change between incarnations.^{[citation needed]}

The 100/2.8 is a macro lens, meaning that it can project an image onto the sensor ( film or CMOS ) the size of the object it's focused on. On traditional film, or a full frame digital SLR, one can fill the frame with a 24×36 mm object. ( This is known as life-size or 1:1 magnification. ) Despite the macro designation, the 100/2.8 can focus to infinity like any other lens. In fact, it's often used for portraiture.

Aside from the macro feature, the 100/2.8 Macro stands out among the 80 or so Canon EF lenses for its resolution and contrast. This should come as no surprise, because "macro lenses are among the best lenses there are for 35 mm format."^[1]