Canon EF 600mm f/4L IS USM - Canon EF Mount

The Canon EF 600mm f/4L IS USM is a professional super-telephoto lens designed for wildlife and field sports photography. As a first-generation Image Stabilized (IS) model, it features a complex optical design including fluorite and UD elements to suppress chromatic aberration. The f/4 maximum aperture provides significant light-gathering capabilities and excellent subject separation, while the ultrasonic motor (USM) ensures fast, quiet autofocus. When inspecting a used example, check the Image Stabiliser for smooth operation and ensure the AF/MF override is responsive. SDS verifies the internal optics for dust or fungal growth, which can occur in older large-element lenses. Given its weight of over 5kg, the tripod collar and foot should be checked for secure locking and smooth rotation. Examine the front element for coating scratches, as replacements are costly.