"Paul Rubin" <http://phr.cx@NOSPAM.invalid> wrote
news:7xps7yi1sl.fsf@ruckus.brouhaha.com...
> "Neil Harrington" writes:
>> There'd be no purpose in that as far as I can see. If you design a long
>> lens
>> there's no reason to make the image circle smaller than the 35mm frame
>> anyway, so might as well make it suitable for full frame even if only a
>> dwindling number of 35mm photographers are still using that.
>
> No I don't believe that. Where is the Nikon FF 90-250/2.8, which is
> available for the OM 4/3 system?
I don't really know much about the Four Thirds system. Isn't that a lot
smaller than DX? Nikon does make a 70-200/2.8 VR, in addition to the
80-200/2.8 -- I have no idea how the Four Thirds lenses compare in size with
those. But if they have a lens that's 250mm f/2.8 at the long end, that
establishes the minimum objective size no matter what size format it's being
used on. And that in turn largely determines how long it's going to have to
be, I think. They may be able to make a very short 90-250mm zoom (my Nikon
55-200 is very short), but not if it's f/2.8 all the way.
There's no question that as you go to smaller and smaller sensors you can
more easily get large zoom ratios in fast lenses of small size. I have a
MiniDV camcorder with a 20x f/1.6 lens, and that's fairly modest for the
camera type. But that's a very, very tiny sensor.
Neil