I can see the benefit of designing and manufacturing a *wide-angle* lens specifically for APS-C sized sensors instead of full-frame sensors: you will get smaller, lighter, and cheaper lenses.

But is it really useful *only* for wide-angle lenses? For example, the [Wikipedia page on Canon EF-S lenses](http://en.wikipedia.org/wiki/Canon_EF-S_lens_mount) writes:

> 
> The proximity of the rear element to the image sensor greatly enhances the possibilities for wide angle and very wide angle lenses, enabling them to be made smaller, lighter (containing less glass), faster (larger aperture) and less expensive. Most current Canon EF-S lenses are wide angle.
> 
> 
> 

Hence the question: does the size of the sensor matter that much with **fast telephoto prime** lenses?

For instance, if there was a Canon EF-S 200mm f/2.8 lens, would it be much smaller, lighter, and cheaper than Canon EF 200mm f/2.8?