Originally posted by Tommy To get back on topic a little....personally I would only buy a 16-28 if I had a full-frame sensor. With APS-C, the zoom range is a little strange....
Strange? I have a 24-40 F 2.8 Tokina AT-X manual focus lens; the 16-28's angle of view on APS-C would be similar to a 24-42mm FF lens, about the same. Nothing strange about it.
Originally posted by Tommy I can't imagine that many 1D MkIV users buying third part lenses so they must be aimed at the cheaper FF cameras. We haven't seen many of these....A850 is one. Do you think Sigma, Tokina and Tamron knows something about Pentax (or Sony, Canon, Nikon or Olympus for that matter) plans for sensor sizes in future cameras before we know?
Who knows? What they definitely
do know, however, is that Nikon and Canon are the biggest players, and both (in addition to Sony) make FF dSLRs. Little point catering only to APS-C when FF lenses can also be used on APS-C anyway (the reverse is
not always true). If you look at the third party lens offerings, what you basically get is some specialized lenses to expand the wide end of the range, with coverage up to about 150mm (in terms of the high quality stuff, not the slow, variable aperture, cheap lenses with zoom ratios exceeding 3:1). Beyond that, you can have any lens you like, as long as it's full frame.