PROFILBARU.COM

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.

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 ^[1]	f/5.6L^[2]	f/4.5–5.6 USM^[3]
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