P3D Re: 2x2 stereo Reel 3-d response

[Larry Berlin <lberlin@xxxxxxxxx>]

>Date: Thu, 25 Mar 1999 
>From: Alan Lewis <3-d@xxxxxxxx>
>To: "photo-3d@xxxxxxxxxxxxxxxxx" <photo-3d@xxxxxxxxxxxxxxxxx>
>............
>OK, so let's boil down and ferment this information on the various full
>frame one piece mounts.  If one where to spec. a one piece full frame,
>dual orientation mount that accepts the standard single mounted 35mm
>slide and would be most useful for projection and viewers, what would it
>be?  Would it be a material change on a currently available mount
>(Franka), or a re-introduction of an older size mount made from metal?

*****  Old standards are not necessarily the best option when change is
being considered. Retooling with an updated concept is better than adapting
an older one and having to retool anyway.

The *goal* is adaptation of current trends (in commercial photography
materials and services) towards improving general access to stereo slides.
Since that obviously means working with 2x2s, the obvious direction is a
minimum hassle slide joiner process.

The *one piece mount* concept exists primarily to solidify essential
geometric alignments between two images. No system of temporarily taping and
untaping later can qualify as realistic in the larger sense, though useful
on the small scale.

Instead of asking whether to adapt the Franka or go to an old metal device,
start by looking at the givens and take the most direct route to the desired. 

Materials: paper, plastic, metal, ceramic...

Existing: 2x2 slides from typical commercial processing. Usually paper or
plastic and of standard size. If the super slides mentioned portend a future
trend, then plan for flexibility towards more panoramic views. 

Most direct route: attach two standard slides together by some means that
can be done either by hand or machine easily and provide rugged protection
for projection/storage/handling.

One issue with super slides... If they are wider than standard 35mm, and
they go into the same holding device as the 2x2s, they need to be aligned by
their image centers, not by outside edges... That means that for 35mm
standard 2x2s, there should be less than 1/2" between them so that the super
slides with the same centers won't extend beyond the 4 1/2" total width. 

Or the total width needs to be determined by how wide the super slides make
things. What would that wider size be, with the supers at the same centers
for projection as the 2x2 standards?

One mount, both std/super varieties, the same projector or viewer...


>
>Somehow, to me, it always comes back to using dual full frame projectors
>with single mounts and just living with it, but I would like to
>understand all of the opinions on this topic.
>
>It's even cheaper to buy two used Ektagraphic projectors than one
>Realist projector.
>
>But if you are only taking horiz. format full frame, then it makes sense
>to stick with the Realist format viewers and proj. by using the RBT full
>frame Realist size mount.


****  The issues are very different with dual and separate machines compared
to stereo projectors. You assume that the slides are aligned with each
other, and you try to get two separate machines aligned and with vague
precision dance together consistently, slide after slide.

That's just projection one time. Later (and before hand) you have to keep
track of separate trays of slides. What if a tray of slides spills? And the
next time they are projected the alignment issue is there again, alive and
waiting to snarl things. Hats off to those who meet this challenge with good
results!

The option of *just living with it* only exists for avid hobbyists. Living
without it is what the public chooses to do and that's the challenge we
face, to literally turn the situation around. 

>Date: Thu, 25 Mar 1999
>From: Robert Thorpe <thorpe@xxxxxxxx>
>..............
>To muddy the waters even more on this topic, one could look into
>having vertical or horizontal full frame 35mm mounts made with the
>same outside dimensions as the Medium Format mounts available 
>from Rocky Mountain Memories:
>
>     http://www.frii.com/~rkymtmem/mounts/spicer.mf.html
>

*****  OK, so one mount, three formats...,   what size was that again? 

Larry Berlin

Email: lberlin@xxxxxxxxx
http://www.sonic.net/~lberlin/
http://3dzine.simplenet.com/


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