> How sure are you it does not have *any* focus shift? Or are we just
> not seeing it on film?
Of course it's going to have SOME focus shift. At least you'd think it
would. But as you stop the lens down, the DoF increases which covers
up the fact the focus shifted. What happens is that you'll get a
little more foreground or background in-focus. Using the lens wide
open means no focus shift anyway, so non-issue.
> I would be amazed if a non-aspherical, 30-year old design has less
> focus shift than an expensive, aspherical design.
Maybe not. It depends on the inherent focus stability of the lens
design itself. Aspherical lens designs often denote that the lens is
not natively intended to be shot at a particular aperture and/or
distance. The aspherical elements correct for the non-ideal. As you
correct for the non-ideal, weird things can happen.
> The EF 50/1.2L is a heck of a lot more tough though - weather sealed
> and the plastic casing is extremely strong, I have heard
> of one dropping and rolling down a stairway with no damage. But at
> three times the price (and size/weight), the Zuiko is a gem!
Not necessarily so It may seem a lot tougher, but is it really? I'd
suggest that the Zuikos aren't wimpy at all. They are smartly
engineered. Also, relatively weather resistant. I've rain drenched my
gear many times. My 100/2.8 had a HUGE impact with a vehicle. Neither
of which has affected it at all.
AG
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