Archived posting to the Leica Users Group, 1996/12/06
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Ten minutes ago, I wrote:
> The latest Leica Views which I received only a few days ago says that
> one of the functions of the contacts is to communicate information
> from a ROM in the lens to the processor in the camera.
Ok, it sounded so stupid that I questioned my memory and went and
looked it up. The R8 article in the "Fall 1996" LeicaView says, and I
quote: (any typos are mine)
For flash use, technological advances have been incorporated into the
R8's through-the-lens (TTL) flash exposure measurement. The R8
requires an SCA 3501 flash adapter, part of the newer SCA 3000 flash
system, and can be used with most SLR flash units. The new Leica R
lenses have a ROM module that stores information and transmits it to
the camera via a contact strip. When certain flash units are used,
the zoom reflector automatically adapts to the focal length of that
lens, providing a perfectly balanced light source based on the ambient
light and distance-to-subject. Current R lenses can be converted to
ROM. In addition, this flash adapter allows optional flash override
so the flash exposure measurement can be controlled separately from the
ambient light measurement. The lightweight shutter on the R8 allows
flash syncronization time of 1/25O second.
Still, the contacts and the ROM lenses seem like a lot of work to go
to for a minor feature. It is interesting to note that they imply
that the lens sends the focus distance information to the camera via
the contacts. I can imagine that this information would be needed for
autofocus as well. Hmmm.
--Jim Dempsey--
jjd@bbn.com
http://frontdoor.bbn.com/users/jjd