According to a reliable rumor source (thank you!) Canon is testing prototypes of the following DO super telephotos; RF 400mm f/3.5 DO IS USM RF 400mm f/4 DO IS USM RF 500mm f/4.5 DO IS USM RF 500mm f/5 DO IS USM RF 800mm f/9.5 DO IS USM According to the source, only one of … Continue reading New rumor of Supertelephoto DO’s and the R1 [CR2]