Should Canon keep 4 different mounts when Sony has only one and Nikon 2?
Does that sound like a good idea in a situation where the market size is stretching dramatically?
Some possibilities:
- Canon is finished developing lenses for EF-S mount; new lenses for its smaller sensor format will be M-mount only from now on.
- M mount lens offerings will at most expand modestly, as it is aimed at a market with modest needs, some of which are tolerably met with adaptor mounted EF-S and EF lenses which will continue on the market so long as enough people are buying them for EF-S-, EF- and M-mount cameras.
- Future EF mount development will slow too, with the current large and good selection needing only a few updates during the coming slow OVF twilight.
- On the longer, term the M lens range will be moderately expanded, but look at EF-S and DX offerings lately to get an idea of how modest the tempo of those new lens design efforts can be.
- If so, then only the R lens system will demand a lot of new lens investment, and maybe EF if demand for high end DSLR's persists.
- Canon has decided on the perhaps old-fashioned idea that
different format sizes are best served by different lens mount sizes! A smaller format aimed mainly at less "gear-ambitious" photographers benefits from a smaller mount diameter that allows somewhat smaller cameras and more slender lenses, while a larger format aimed at offering state-of-the art high end performance benefits from a larger mount diameter. In the words, Canon does not see the cross-over market of
people with cameras in two different formats, using the smaller format ones as backups, or for extra telephoto reach [rather than using a teleconverter] as big enough to let it impede optimal design for each format separately.
The ability to use lenses designed for a larger format on a smaller format body was far more important with the film-digital SLR transition, when the huge selection of "legacy" lenses were for the larger format, and so optically suitable for use on the smaller format.