I've cc'd this item to Jason Schneider at Pop. Perhaps he knows something _we_
don't and will share it!
There's _one_ good thing about Olympus's official discontinuance of the OM
system -- the company has "burned its bridges." Olympus is now financially and
psychologically "cut off" from its silver-based professional SLR products.
It's obvious that high-density 24mmx36mm CCD or CMOS sensors will eventually
become available at a "reasonable" price. (Contax and Pentax are scheduled to
introduce cameras with such sensors in 2002.) When that occurs, owners of _all_
SLR systems will demand a body that uses their existing lenses.
Whether Nikon, Canon, and Minolta will do so is questionable. Many companies
claim their lenses -- especially wide-angle designs -- won't work properly with
a full-frame sensor. (See my comments about compatibility below.)
Olympus, on the other hand, having no lenses, has no compatibility problems! It
might very well produce an SLR with a few general-purpose zooms and a handful
of specialty fixed-focal length lenses optimized for digital imaging. This
would return Olympus to the professional SLR market, without any "competition"
(either in the marketplace or in terms of its financial and production
resources) from existing products.
Olympus has established itself as one of the leaders -- if not _the_ leader --
in digital photography. A full-frame pro digital SLR with interchangeable
lenses would be a body-blow to its competitors. But I'm not holding my breath.
A word about lens compatibility. The cells in a CCD sensor sit slightly below
the conductive paths that surround them. This means that, the more-acute the
angle of light striking the sensor, the greater the shadowing effect of the
paths, further exaggerating the normal edge falloff that occurs with wide-angle
lenses.
Olympus claims their new lens design gets around this problem by moving the
exit node farther from the film plane, thus making the angle of attack less
acute. This doesn't sound right -- the angle at which the light rays strike the
film is, by simple geometry, unavoidably linked to the lens's angle of view.
How can you make the angle less-acute without simultaneously reducing the angle
of coverage?
So I did some research. In every reference I checked, a lens's focal length is
_defined_ as the distance from the exit node to the film plane. In other words,
you can't change the position of the node without simultaneously changing the
lens's focal length. QED -- Olympus's claim is not kosher.
Regardless, the problem of edge falloff -- whatever its cause -- is easily
solved in software. It's a trivial matter to "map" the falloff for each lens,
then process the image to remove the falloff. This could be done in the camera
or with an image-editing program.
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