Originally Posted by
Hades2k
It baffles me that canon would introduce a brand new system and then slap another mount on it - why oh why did they not make it EF-S so that every piece of glas can be used?
That's what kept me of the Nikon1 System earlier, I would love to use my glas without a special 200$ adapter.
The APS-C size sensor is great tho, making it really something to think about.
For the same reason they made the EF-S mount originally. A smaller sensor allowed for a smaller mirror which allowed for lenses that could have smaller spacing and be made lighter and cheaper. Now with no mirror they can do that again - smaller, lighter, cheaper lenses. And to allow the protrusion of the EF-S lenses to fit, the body would need to be thicker. When you're trying to build a small, compact, light body, you take advantage of these opportunities.