Advanced Birding/Launch setup, also works wonderfully for any distant subject, including surfing, skiing photos from land. The R7's 32mp APS-C sensor gives a 1.6x crop factor, making the effective focal length of the EF 400mm f/2.8L III 640mm. This bundle is best for the advanced photographer who needs the maximum versatility and that is not shooting in very low light conditions. A basic EF to RF converter is included if needed. 2x and 1.4x  EF converters available for an extra charge. CPL Filter Adapter and CPL Filter available for an extra charge.