speedoo wrote:This is the big problem with Canon DSLR's. They change lens systems every now and then, which makes owning their cameras and lenses a bit of a crap shoot, because you never know whether some new lens system is going to come along and screw you.
Pentax, on the other hand allows you to use all Pentax lenses made since the 1950's on even their newest DSLR's.
I think you are overstating that a bit. First there were the FD lenses. Then a few decades ago they introduced the EF autofocus lenses, which work with all the cameras since then, including all current models.
They have added EF-S lenses for the small sensor cameras, that take advantage of the smaller sensor to allow the lenses to be smaller and cheaper. These work with all the digital SLRs Canon has made except the full-frame ones (1D, 5D, and the new 6D).
The EF-S lenses work with all the digital Rebels, all the x0D cameras, and the 7D.
The EF-S lenses have not replaced the EF ones. Those are still available, still being made, and still work with all Canon EOS cameras, digital and film.