So, we always see "Why can't we have a 24-70mm f/1.8 IS?" threads and the like, and we all know the reasons why we can't have such a lens. But would someone with more optical design knowledge tell me if the following would be mildly possible?
A 50-85mm f/1.8 (or maybe variable aperture, like 1.4-1.8 or 1.4-2)
A 35-50mm f/1.8 (")
I love my Sigmalux, but on my 40D it was often too long, and now on my 5D2 I find it's often a little too wide. In the last month, there have been several times when I'd have KILLED to have just that extra little bit of reach/subject separation. But I can't really bring myself to pay for and then carry around two primes that are so (relatively) close to one another. But I'd LOVE to have them both at the ready.
So why isn't THIS a possibility? Clearly there'd be no purpose in having a 35-50mm zoom with an aperture even as fast as 2.8...but when you've got the equivalent of two fast primes without the need to change lenses, don't you think that'd be worth some extra dough? I can't imagine that a 35-50 would be THAT enormous...maybe about the same as a 24-105 or a Brick?
Another thing; I wouldn't even need a "zoom" per se...I'd be happy with a lens that could just snap back and forth between the two FLs. However, I have no idea if this would make any difference as far as construction goes.
So tell me...is this another idiotic fantasy or is it feasible? Would any of you buy one?