John Lind wrote about the 300mm f/4.5
> Mine is an F.Zuiko (confirming SC and six
> elements)... The contrast has been more than sufficient for me and
> it passes my "unscientific-but-practical" sharpness test with medium speed
> transparencies (Kodachrome-64 and Ektachrome-100) projected on a 50" screen.
The contrast on mine (also an SC F.Zuiko) is mostly very good, but
it doesn't like being pointed into the sun. At the moment, I rarely
want to do that with a long lens, being more interested in getting
enough light on the subject to keep the shutter speed up. If I start
to use it more for landscapes, that might change.
> The MC would be more important to me with a symmetric design, but still it
> takes a back seat to condition and overall performance.
I agree that condition is more important than MC-ness. I'd rather
have a lens that produced excellent results most of the time than
one which produced mediocre results all of the time.
Another factor influencing flare and ghosting resistance is
the size of the front element. I know that my late MC 50mm f/1.4
is much less flare resistant than my "SC" 50 mm f/1.8; in fact,
it's about as bad as my SC 35mm shift. This is consistent
with John Lind's symmetry/asymmetry theory, though I don't
know enough optics to understand how that would work.
Finally, I think there may be tradeoffs with the multicoating
used by some manufacturers. I've been looking at a graph in
the B+W filter brochure. Reflection with SC varies from 2.5%
to 4 0n a U-shaped curve with the minimum at 520nm (blue-green).
With their MC, it is a low and almost constant 0.5% between
400nm and 640nm, crossing the SC curve at 380nm (blue) and
760nm (orange) and rising to quite high levels at the
violet and red ends of the spectrum. This tells me that
their MC filters aren't going to be very good in some conditions
under which I'll use them. (A pink cast may "improve" some
European landscapes but not Australian ones.) I also have some
cheaper SC filters which take on a distinct pink cast under
flare-inducing conditions and some SC Hoya ones which don't,
so there's also good and bad single-coating.
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