Re: [photo-3d] Re: Wide-angle Stereoscopy and the LEEP 2/2

["Don Lopp" <dlopp@xxxxxxxxxxxxxxx>]

As reguards to the LEEP camera, I have never seen one but  I have used the
LEEP viewer  with LEEP slides and found there quality to be equal to slides
taken with a NISHIKA stereo camera--poor to put it mildly-I do not
understand the theory of taking a fuzzy slide and viewing  through a optical
lens that will make it look OK--I do not buy into this strange theory as of
to day and I am waiting to be proven wrong DON
----- Original Message -----
From: <abram.klooswyk@xxxxxx>
To: <photo-3d@xxxxxxxxxxxxxxx>
Sent: Sunday, February 18, 2001 6:23 AM
Subject: [photo-3d] Re: Wide-angle Stereoscopy and the LEEP 2/2


> In December 2000 there was a P3D thread on the LEEP.
>
> The news about the LEEP system (Large Expanse - Extra
> Perspective) was spread by Paul Wing in 1981, he wrote the
> article in Stereo World (recently referred to in P3D), it was
> in his column "Equipment Notes": "How about the LEEP system",
> Stereo World Jul/Aug 1981 vol 8 Nr 3 pages 20-21.
>
> I wrote on the news also in Jul/Aug 1981 (without having seen the
> prototype) in the Dutch 3-D Bulletin Nr 57, and again in the
> Jul/Aug 1982 3-D Bulletin Nr 63. First a price of $200 had been
> mentioned for a basic LEEP system (camera and viewer).
> I commented that I had doubts on possible quality for that price,
> as a single 35 mm lens for a 6 x 7 camera (Pentax or Mamiya)
> costed a multiple of that amount.
>
> In an article in "Design News" Nr 21, of Sept 21, 1981 by
> "East Cost Editor" David J. Bak: "Transparency 'corrects'
> distortion, color fringing" was explained how the LEEP system
> was supposed to correct lens errors.
>
> "A wide angle photo-viewing system will impart distortion-free
> color imaging with minimal fringing." "... the LEEP method
> (...) a predetermined amount of positive distortion and
> lateral chromatism. Transparencies display barrel-shaped
> images and pronounced color fringing (...). When seen through
> the magnifying viewer lenses, images are corrected in that
> straight lines are straightened, and object appear as the same
> size as at the original vantage point of the camera. The
> system not only corrects distortions, but the color fringing
> on the transparency substantially neutralizes the lateral
> chromatism of the magnifier lenses."
>
> A figure shows color fringing from a point source of white
> light by a "simple camera lens" on film, and a symmetrically
> placed  "simple viewer lens" which unites the spectrum again
> to a white line.
>
> There was more about this in the description of the US patent
> 4406532, issued Sept. 27, 1983: "Wide angle color photography
> method and system", inventor Howlett, Eric M.
> (Today the full patent description is on-line, ref. see below,
>  fig.2 illustrates the "Neutralizing of Lateral Chromatism").
> In short, it is proposed to correct camera lens color dispersion
> by opposite viewer lens color dispersion.
>
> Of course anamorphotic lenses are used in systems like Imax,
> but only for geometrical transformations, not for handling
> color dispersion. So at first the LEEP system seems a too
> optimistic scheme, resembling trying to correct an out-of-
> focus transparency by de-focusing the projector lens...
> This seems in conflict with experience and laws of entropy.
> (I'm working on my General Unified Theory of Garbage, which
> will cover entropy, Bermuda triangle events, Murphy's law,
> chaos, American President Elections, the second law of
> thermodynamics and other strange phenomena).
>
> Stereoprojection of slides is to some extent optically
> symmetric to stereophotography, but stereoscope viewing is
> not. In viewing, the lens makes a virtual image at the same
> side of the lens as where the transparency (or photograph) is.
> You cannot easily use a camera lens for viewing.
>
> However, the patent description was accepted by the US Patent
> Office, so there must be some truth in it, and indeed the LEEP
> pictures seem to support the claims. If the claims of the
> patent description are right, the LEEP viewer can only be used
> to view pictures from the LEEP camera. (So I wonder if Don
> Lopp has done that, or tried it with other pictures?)
>
> >From 1982 I was one of the sponsors of the LEEP project, in
> fact camera serial #32 would become mine (but never was :-( ).
> I wrote to Eric Howlett about van Albada's efforts, and he
> wrote back that he indeed had filed his patent application
> with the van Albada paper as main reference (it is indeed in
> the patent description).
>
> The project went wrong as we know. There were some irregular
> spaced newsletters from Howlett, who used the firm and brand
> names LEEP, Stereovision, LEEPMA and Pop-Optix Labs in the
> mailings. (One of the mailings included the sheet recently
> uploaded to the files section by Rod Sage, it is in my LEEP
> file, date Feb 1982. The lenses shown were from the production
> series. The text gives pre-production camera details, which
> slightly differ from the actually used specifications which
> are in Werner Weiser's book "Stereo Cameras since 1930",
> see reference in posting 04 Feb 2001).
>
> In 1989 Howlett wrote: "In the middle of 1985 we actually
> shipped three LEEP systems (...)". A foot note added that one
> of them had "conked out".
> This was not very encouraging, 8 years after the first public
> LEEP announcements. Apparently financial and personal problems
> were too great.
>
> In the mean time I had seen Paul Wing's LEEP pictures (and his
> camera) on several occasions, and I still hoped that the
> production number would reach #32, but eventually Paul told me
> confidentially that he didn't believe any more LEEP systems
> would ever be produced, which till today seems right. A sad
> outcome, but I would sponsor a new wide-angle stereosystem
> again, if there was some change to buy one.
>
> Abram Klooswyk
> ---------------
> Below a summary of LEEP web references.
> Patent text:
> http://www.delphion.com/details?&pn=US04406532__&s_all=1
> Patent figures:
> http://www.delphion.com/cgi-bin/viewpat.cmd/US04406532__
> LEEP "site":
> http://world.std.com/~leep/cat003/arv-1.htm
> Pictures of LEEP camera and viewer, on the
> Stereo New England / PHSNE site:
> http://www.phsne.org/stereocameras/35mm-rollfilm/leep.jpg
> http://www.phsne.org/stereocameras/35mm-rollfilm/leep_viewer.jpg
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