Blending a versatile telephoto focal length with a modest form factor, the EF 300mm f/4L IS USM is a long-reaching prime and member of Canon's elite L-series of optics. Two ultra-low dispersion elements are used to significantly reduce color fringing and chromatic aberrations in order to achieve a high degree of clarity, and a Super Spectra coating has also been applied to maintain contrast and color fidelity when working in difficult lighting conditions. Complementing the imaging attributes, this 300mm f/4 also features an Image Stabilizer to minimize the appearance of camera shake by two stops for sharper handheld shooting. The ring-type USM is employed, too, to deliver quick and quiet autofocus performance along with full-time manual focus control. Additionally, a removable rotating tripod collar is included for stable use of the lens atop a tripod or monopod.
- Portrait-length prime is designed for full-frame Canon EF-mount DSLRs, however can also be used with APS-C models where it will provide a 136mm equivalent focal length.
- Notably fast f/1.4 maximum aperture offers extensive control over depth of field for working with selective focus techniques. This bright design also benefits working in low-light conditions.
- One glass-molded aspherical element helps to reduce distortion and spherical aberrations for improved sharpness and clarity.
- An Air Sphere Coating (ASC) has been applied to lens elements to reduce backlit flaring and ghosting for maintained light transmission and high contrast in strong lighting conditions.
- A ring-type Ultrasonic Motor (USM), along with optimized focusing algorithms and a high-speed CPU, is employed to deliver fast, precise, and quiet autofocus performance as well as full-time manual focus override.
- Optical image stabilization minimizes the effects of camera shake by compensating for up to four stops of shutter speed.
- Rounded nine-blade diaphragm contributes to a pleasing out of focus quality that benefits the use of shallow depth of field and selective focus techniques.
- As a member of the esteemed L-series, this lens is sealed against dust and moisture for working in inclement environmental conditions.
- Fluorine-coating on exposed elements affords protection to the optical system, resists smudging and fingerprints, and is easier to clean.