Re: [photo-3d] Donaldson viewer - more info

["John A. Rupkalvis" <stereoscope@xxxxxxxxxxxxx>]

Yes, the Donaldon camera and viewer system are unique and very interesting.
And, as noted, very expensive.

The 7p format is identical to that of the Verascope, Belplasca, et al.  And,
also as noted the centerline spacing differs.

The camera is the only manufactured one I know of with adjustable interaxial
as well as adjustable convergence.  I saw a picture of one once, but have
never actually seen the camera.  Maybe someone has some illustrations or
other info to share.  I think this would be interesting.

I say "manufactured".  My guess is that very few of them were made, and they
were most likely hand-made at that (ala RBT).  They were much more expensive
than RBTs.  I seem to recall their being in the five figures.

Anybody have any more info?

JR

----- Original Message -----
From: "Dr. George A. Themelis" <drt-3d@xxxxxxx>
To: <photo-3d@xxxxxxxxxxx>
Sent: Friday, October 20, 2000 7:39 AM
Subject: [photo-3d] Donaldson viewer - more info


> OK, here is the information I gathered from various
> personal replies.
>
> Donaldson was a doctor and he designed a macro camera
> to take pictures of the eye.  Wolfgang Sell has a Donaldson
> viewer for viewing an uncut roll of slide film of 7p format
> (with prisms to do the R to L reversal).  Also, there are
> rotary viewers too.
>
> My viewer takes single slides and the format matches what
> Norm Henkels emailed me:
>
> >I believe the Donaldson format is used by ophthalmologists. It uses a
> >spacing of 58mm vs. 62.3 for Realist format. The frame/aperture size is
> >about 27.5mm. I get these dimensions from a box of #2427 Sigma mounts
> >formerly produced by George Skelley.
>
> I noticed when looking at Realist-format slides in my viewer,
> I cannot fuse the infinity points because the lens spacing is
> smaller than the standard Realist infinity separation, which
> agrees with what Norm wrote.  Also, from the aperture size
> of 27.5mm it appears that this is 7p (and not full frame as
> I originally thought) format, as Wolfgang says.
>
> Norm is kind enough to offer to send me a sample of this mount
> and, for those interested, he has more for sale.
>
> The price of these viewers is in the range of $200 to $250,
> I was told.  The camera runs into thousands of dollars.
>
> This unusual camera/format system could make a very
> interesting article in one of the stereo publications, I would
> think...
>
> George Themelis
> http://home.att.net/~drt-3d/
>
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