Overview

The Canon RF 400mm F2.8 L IS USM is a professional-grade super-telephoto lens that shares the same optics as the EF Mark III version, essentially adding a built-in adapter for the RF mount. It delivers outstanding image quality with minimal aberrations and strong background blur. Build quality is high with weather sealing, but the lens is heavy at ~6.5 lbs, making handholding a workout. Autofocus is excellent, and stabilization is rated at 5.5 stops. It suits sports and wildlife photographers willing to pay ~$12,000.