Canon EF 100-300mm lens

The EF 100–300mm refers to three telephoto zoom lenses produced by Canon. They are of the EF lens mount that is compatible with the EOS line of cameras.

A Canon EF 100-300mm f/5.6L zoom lens

The three versions are:

• f/5.6
• f/5.6L
• f/4.5–5.6 USM

The two 5.6 versions were contemporaries, launched at the beginning of the Canon EOS system. The L version had a different optical construction which improved sharpness, color, and chromatic aberrations. Otherwise the lenses were physically similar. Canon decided to upgrade the non-L version in the early 1990s to the 4.5-5.6 version, not the L. It had improved styling, a ring zoom control instead of push-pull, and a larger (faster) aperture at the wider end. It also made use of a much faster and much quieter Ultrasonic ("USM") motor for autofocus control, instead of the Arc-Form Drive ("AFD") found on the 5.6 lenses. The L version never received this upgrade, and it lasted long after the 5.6 non-L had been discontinued. Following Canon practice, the L lens was sold including its lens hood and protective case.

Lenses

Attribute	f/5.6	f/5.6L	f/4.5–5.6 USM
Image stabilizer	No
Ring USM	No		Yes
L-series	No	Yes	No
Diffractive Optics	No
Ultra-low dispersion glass element	No	Yes	No
Synthetic Fluorite glass element	No	Yes	No
Macro	Yes
Short back focus	No
Maximum aperture	f/5.6		f/4.5–5.6
Minimum aperture	f/32		f/40
Weight	685 g	695 g	540 g
Max. Diameter x Length	75 mm x 166.8 mm	75 mm x 166.6 mm	73 mm x 121.5 mm
Filter diameter	58 mm
Horizontal viewing angle	20°–6°50'
Vertical viewing angle	14°–4°35'
Diagonal viewing angle;	24°–8°15'
Groups/elements	9/15	10/15	10/13
# of diaphragm blades	8
Closest focusing distance	2 m	1.5 m
Currently in production?	No
Release date	March 1987	June 1987	June 1990