[rollei_list] Re: OT: Stereo Photography

On Thu, Jul 22, 2010 at 7:34 PM, Richard Knoppow <dickburk@xxxxxxxxxxxxx> wrote:

>   I don't think anyone answered this. The distance between the lenses should
> always approximate the inter-ocular distance, approximately 65mm. However,
> at great distances, there is virtually no stereo effect. However, there is
> nothing wrong with using any arbitrary spacing for an exagerated or enhanced
> stereo effect. This done commonly in aerial photography where two
> photographs taken a few seconds apart as the aircraft is moving can be fused
> into a stereo image. There are viewers made for examining aerial photos
> consisting of magnifying eyepieces with two mirrors on each side to get the
> right spacing. Sometimes one finds old aerial survey photos which have
> inadvertent stereo pairs. I remember looking at some years ago at the UCLA
> geography department which had the archives of two of the old time aerial
> survey companies operating in the Los Angeles area (Spence was one and I am
> drawing a blank on the other). Among the pictures were some of the Twentieth
> Century-Fox movie lot. I could easily see people in the photos when looked
> at in stereo. When looking at single images I could tell they were people
> after seeing the stereo images but would never have known otherwise.
>   Ideally, for stereo the lenses should also face inward slighly just as
> one's eyes do but I don't know of any stereo cameras which actually do this.
>   The problem with the slider is that one can take only still life with it.
> The closest two Rollei camras can be placed results in about a four inch
> spacing between lenses. This would be fine for photographing distant objects
> where one wanted enhanced stereo. I have seen rigs for using two 35mm
> cameras oriented vertically, cameras like the Leica thread mount models can
> be close enough for proper spacing when mounted this way.
>    One of my continuing regrets was not buying a Heidoscope (or maybe it was
> a Rolleidoscope) I saw at a camera swap meet many years ago. I don't think
> they wanted much for it then and I could have gotten it. I have rarely seen
> others and always for high prices.
>
> --
> Richard Knoppow
> Los Angeles, CA, USA
> dickburk@xxxxxxxxxxxxx


Hi Richard -

Here was my reply:

>I have shot my Rollei TLRs on a slide bar with good success. Of
>course, the subject and light must be completely static.

>You're thinking along the right lines relative to stereo base. If you
>google "stereo base calculator" you'll get some options/opinions.
>Here's one of them:

>http://www.stereoeye.jp/software/sbcalc_e.html

>Shooting Hyper (and hypo-stereos) is both science and art; prepare to
>get contradictory advise and test shoot to get results that satisfy
>you.

To get a bit more into an advanced stereo discussion, stereo base is
not only a function of distance but also of lens and viewer
magnification. While there is nothing wrong with greatly exaggerated
hyperstereo, it can look both ridiculous and uncomfortable depending
upon what known references are in the composition and the angle at
which it is shot. Aerials shot straight down (or nearly so) from the
belly of a plane can tolerate quite a bit of hyperstereo for logical
and obvious reasons but more normal shooting angles typically cannot
unless you are looking for artistic effects.

It is true that the subject must be static when using a single camera,
it is equally true and just as important that the light must also be
static.

Relative to lens spacing a 4-5 inch stereo base with twin Rolleis will
produce natural appearing stereo from about 8 feet and deeper. The
brain has a lot of flexibility to compensate for slightly greater
parallax with distant objects and images shot with MF twin rigs from
about 8 feet on do not look unnatural.

The problem with twin vertically oriented 35 mm cameras is the switch
to portrait film format which is very limiting and given the nature of
stereo shooting and subjects most shooters don't like it.

The Heidoscops and Rolleidoscops are nice MF shooters but they do need
scrupulously clean lenses and the shutters and viewfinders usually
need a fair amount of work. There is an MF stereo camera out of China
now with twin Planar type lenses which gets very high marks from
advanced shooters... it sells for around $1800 US and is a better
choice for a reliable user than a classic Rollei stereo camera. It is
called the TL120-1 and you can google it for more information.

It is incorrect that lenses in stereo imaging should be toed in...
they should be absolutely parallel and fine stereo cameras are
constructed this way. Human eyes only effectively "toe in" at close
distances, closer than one normally shoots stereo. Shooting stereo in
close (macro and micro stereo) is a discipline in and of itself with
it's own set of rules.

I'd also suggest you check out the local LA stereo club:
http://la3dclub.com/about/ and introduce yourself. It is a fine and
storied club with some very famous alumni. If you'd like I can make an
introduction for you... there are some great people there...


Eric Goldstein
---
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