>
> Of course, if you usually expose to the right as I do, chimp the
> histogram and let the meter be damned it doesn't matter at all.
>
And if a person uses a "real meter", or shoots "box speeds", it really makes
things even less an issue.
The biggest issue that I've encountered has to do with the Olympus focus
screen itself. These ultra-matte or whatever they are called screens are NOT
ground-glass type of screens. The matte area is actually what they call
deformed microprisms. Inotherwords, you aren't looking at a random
scattering surface like a traditional ground-glass screen, but instead it's
a surface entirely made up of microprisms (pyramids).
As we remember from the film days, the focusing aids in an SLR comprised of
a split image (two opposing slopes) and a microprism collar. If you used a
too dim focus screen with these screens the focusing aids would black out.
The solution to this was to reduce the angle of the prisms. This had the
unfortunate side-effect of slowing down the focus aids. The aids wouldn't
black out, but they also reacted oddly with wide-angle lenses with
rear-nodal points close to the film-plane..
Then Olympus came out with the 2-series focus screens where they replaced
the entire ground-glass portion of the screen with a very fine microprism
mesh. To keep from blacking out with dim lenses, though, they kept the
angles pretty shallow. Well, the problem there is that the angles which the
light exits a wide-angle lens (especially bright ones with a large diameter
exit pupil) is such that you really don't get much useful angular spread
going on with the microprisms. A 35mm lens, for example, is very difficult
to focus on a 2-series screen because the image barely mushes into and out
of focus.
So, we progress to the digital age. Olympus has continued to use the
microprism mesh from the 2-series screens but adapted the angles of the
pyamids to be better for telecentric lenses. This makes trying to manually
focus wide-angle lenses that don't have a a rear-nodal point far forward to
be difficult.
AG
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