>
> Did it ever occur to you that the maximum opening may be more of an
> advantage to the sales department than to the photographer. After all,
> many
> wide-open shots are made under lighting conditions that preclude any real
> judgment of the difference in stops.
>
Honestly? Yes, the maximum aperture was a huge selling point back in the
'70s and '80s. I think I can find a few articles on the max aperture battles
from that era. But in this case, what puzzled me was just how far off it was
so I knew that I wasn't dealing with marketing hyperbole, but something
different. 2/3 of a stop isn't stretching it, it's completely a different
lens.
So, now I'm contemplating a couple other things that seem to have cropped up
since the digital age.
1. Veiling glare. Most of us have seen where our lenses are less than
stellar when shot wide-open. We're talking about a significant reduction in
contrast when shot wider than, say F4. What if this veiling glare is not a
quality issue with the lenses themselves but the interaction of the lenses
with the camera's tiny mirror chamber and the internals of the camera are
reflecting the light from the front of the chamber back into the lens? I
surely don't recall seeing this kind of image degradation with film. This
seems to happen to me more with the big rear-elemented lenses than smaller.
2. Loss of aperture linearity at the wider apertures with other lenses. Even
my 100/2.8 is doing it! At the risk of suffereing the wrath of Moose, I've
just not mentioned it because I've promoted this lens so much that I'd get
skewered for saying anything bad about it now.
So, through all this testing and what-not I've found that for the E-1 with
50/1.4, the maximum usable aperture is basically just about F2 (it is
landing directly at F1.8 wide open). I would assume that this is a specific
to this lens-camera combination (knowing full well that the E-1 is ANCIENT
TECHNOLOGY and 72 generations of cameras have come since then, so get with
the program...), but other 50/1.4 lenses may not have the same issue due to
the position and size of the rear element and the location of the rear-nodal
point.
AG
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