The RF 400mm F2.8 L IS USM features the outstanding characteristics of Canon RF lenses, such as aperture adjustment in 1/8 stops for video recording and advanced optical IS, a function made possible by the RF mount's communication system, compensating up to 5.5 stops of exposure. Additionally, the lenses offer a dual drive for even faster autofocus in future cameras. Both lenses also have three manual focus speeds, allowing for precise control and full manual focus, enabling adjustments without switching modes. Furthermore, two focus settings can be saved in advance, saving time when quick responses are needed and allowing for beautiful pull-focus effects in video recording. The focus ring can also be used as a lens control ring on some models of the EOS R series.