Re: Digital Stereo

[P3D Brian Reynolds <reynolds@xxxxxxxxx>]

Larry Berlin wrote:
> 
> >From: P3D Robert Linnstaedt writes:
> >
> >One approach to digital stereo is to offer a digital back to be attached to
> >an existing camera body.  Having no familiarity with digital cameras, I am
> >not aware of the obstacles to this approach.  (So let me ignoratly charge
> >ahead....)
> 
> *****  There is such an animal for the Nikon camera line and it's extremely
> expensive!
> 

There is also a Canon version.  Both of these cameras are made by
Kodak.  Although both cameras are based on existing bodies with
interchangeable backs (I think the Nikon was a F4 and I'm not sure
about the Canon), neither of these were really interchangeable backs.
Because the CCD chips are smaller than a single frame of 35mm film
alignment of the chip with respect to the body is critical (both for
getting the scene to match the viewfinder and for focusing reasons).
If you removed the CCD back from the camera you had to send the camera
back to Kodak to be readjusted.  As Larry pointed out the main purpose
of the using existing camera bodies was to allow professional
photographers (the cameras were marketed towards news/sports
photographers and catalog photographers) to continue to use their
existing equipment.

> >.............
> >So why could not an interchangeable camera back be fitted with a digital
> >system?  Why not construct a digital back that would fit the Realist, or at
> >least a stereo viewcamera?
> 
> *****  Could be done, but consider how far fewer Realists exist compared to
> Nikons. I'm sure the digital backs for Nikons are not very widely used, so
> low volumes make it strictly a professional choice when needed. Doing the
> same for a realist would be prohibitively expensive, though you might be
> able to adapt a Nikon digital back....?
> 

I don't think you could adapt either of the backs from the Kodak
cameras, and building a back for the Realist would probably be more
trouble than just building a stereo CCD camera from scratch.  Many
people have built astronomical CCD cameras (see the Cookbook Camera
Homepage at <URL:http://www.wvi.com/~rberry/cookbook.htm>) so I don't
think it is out of the question to build your own.

I think making a digital stereo viewcamera would be even easier, but
much more expensive.  A divider placed inside the bellows of the
viewcamera, and a pair of lenses mounted on a single lensboard would
convert the camera to stereo, and then all you need is a digital back
for the camera.  That's where it gets expensive.  Digital scanning
backs for viewcameras (sort of like a flatbed scanner attatched to the
back of a camera) go for $25,000 to $40,000.  And of course you would
be restricted to still images.

-- 
Brian Reynolds     | "Knowledge, Sir, should be free to all!"
reynolds@xxxxxxxxx |  -- Harcourt Fenton Mudd
NAR# 54438         |     "I, Mudd"


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