Canon EF 300mm f/4L IS USM Lens

NOTE: Some noisiness when autofocusing, does not seem to affect functionality.

The Canon EF 300mm f/4L IS USM Lens blends a versatile telephoto focal length with a modest form factor, a long-reaching prime and member of Canon’s elite L-series of optics. Compatible with full-frame Canon EF-mount DSLRs as well as APS-C bodies, where it provides a 480mm equivalent focal length, it’s well suited to wildlife, sports, and nature photographers who want genuine telephoto reach without the bulk of an f/2.8-class super-telephoto.

Optically, the lens offers a 300mm focal length with a maximum aperture of f/4 narrowing to a minimum of f/32, delivering an 8°15′ diagonal angle of view. The 15-element, 11-group optical design includes two UD (ultra-low dispersion) elements, helping control chromatic aberration for crisp, high-contrast results, along with Canon’s Super Spectra coating to reduce flare and ghosting. A rounded 8-blade diaphragm contributes to the lens’s background rendering.

Autofocus is handled by a ring-type Ultrasonic Motor (USM) paired with a rear-focusing system, delivering fast, precise, and quiet autofocus performance along with full-time manual focus override. Canon’s Optical Image Stabilizer compensates for camera shake with the equivalent effect of a shutter speed two stops faster, offering two selectable IS modes: Mode 1 for standard handheld shooting, and Mode 2, which automatically detects panning direction and stabilizes only in the perpendicular axis, useful for tracking moving subjects.

Build quality reflects the lens’s L-series positioning, with weather-sealed construction and a detachable, rotatable tripod collar for balanced support and quick switching between horizontal and vertical orientations. The lens has a closest focusing distance of 1.5m (4.9 ft.), yielding a maximum magnification of 0.24x (1:4.2), extendable to 0.30-0.04x or 0.37-0.09x with Canon’s EF12 II or EF25 II extension tubes. It accepts a 77mm filter thread, measures approximately 90 x 221mm, and weighs approximately 1,190g (2.6 lb.). The lens is also compatible with Canon’s EF 1.4x and EF 2x teleconverters for extended reach.

As a full-frame-compatible lens, the EF 300mm f/4L IS USM produces its full telephoto field of view on full-frame Canon bodies and an effective 480mm equivalent field of view on APS-C bodies.

Key Features
– 300mm f/4L telephoto prime lens for Canon EF mount
– 15 elements in 11 groups, including 2 UD elements
– Super Spectra coating
– Ring-type USM autofocus with full-time manual focus override
– Rear-focusing system
– Optical Image Stabilizer, 2 modes (standard and panning), approximately 2 stops of correction
– Rounded 8-blade diaphragm
– Weather-sealed L-series construction
– Detachable, rotatable tripod collar
– Closest focusing distance of 1.5m (4.9 ft.); 0.24x maximum magnification
– Compatible with EF 1.4x/2x teleconverters and EF12 II/EF25 II extension tubes
– 77mm filter thread
– Approximate weight: 1,190g (2.6 lb.)
– Compatible with full-frame and APS-C Canon EF-mount cameras