There's very little difference in size, weight, and cost between a 70-200/2.8 with a FF image circle and a 70-200/2.8 with an APS-C image circle. The front group, which is where a significant portion of the money is spent, has to be the same size either way to allow 200mm f/2.8. The most expensive piece of glass in most 70-200mm f/2.8 is an aspherical high index (UD in Canon speak) element which is usually the second or third element in the front group.
To be f/2.8 "equivalent" for APS-C , it would need to be an f/1.8 lens, rather than f/2.8. That makes it even more expensive than a FF 70-200/2.8.
Yeah. I know. I knew this before I was "corrected" by Chunk, and you just repeated what he said. Neither of you are reading what I said, and you're ignoring the context in which it was said.
I said a 70-200mm equivalent f2.8 APS-C, not a 70-200mm f2.8 equivalent APS-C.
We were discussing an APS-C lens to match the zoom range of the commonly used 70-200mm f2.8. That'd be ~45-135mm for Sony/Nikon/Fuji with a 1.5x crop or ~42-125mm on Canon's 1.6x crop. Fuji has one, the 45-150mm f2.8, but it's old and heavy, as has already been mentioned. Neither Sony, Nikon, nor Canon have made one.
A 42-125mm lens would give APS-C Canon users the 70-200mm equivalent range, and f2.8 would give them the same shutter speeds. It'd be smaller and lighter and presumably cheaper than a 70-200mm f2.8.
I said nothing about having an equivalent depth of field or any other sort of equivalence. Let me copy/paste it for you one more time.
I said a 70-200mm equivalent f2.8 APS-C, not a 70-200mm f2.8 equivalent APS-C.
I suppose I should have used the word "
effective" instead, but I seriously doubt it that would prevented the inevitable flood of people arguing equivalence for several pages even though
nobody postulated a theoretical and extremely unlikely 42-125mm f1.8 APS-C lens.
For anyone who wants to continue this discussion, we were/are talking about a lens with a
~42-135mm zoom range with an f2.8 aperture. This range on an
APS-C camera would roughly
effectively match the zoom range and field of view of the commonly used 70-200mm lenses used by professionals for indoor sports, weddings, events, and other things. The f2.8 aperture would let you shoot at the same shutter speeds, albeit with less shallow depth of field, which
everybody understands and doesn't need to be argued further. It should be lighter and cheaper than a 70-200mm f2.8, which on a Canon APS-C camera would give an effective 112-320mm full frame field of view, but might be too long/narrow, especially if the situation calls for the 70-200mm field of view.