[MF3D.FORUM:301] Fixed Vs. Dual camera rigs...

["Stuart Johnson" <gcsphoto@xxxxxxxxxxxxx>]

Bill,

    I have been shooting 'Stereo' for several years now with a dual camera
rig (2 Olympus cameras).
It has been a great advantage to be able to alter the stereo base by
adjusting the cameras on various slide or fixed platforms for close-in to
'hyper' (wide base) shooting.  There are interesting effects gained by
over-emphasizing the stereo base for example.  I liked the idea of being
able to change my lens groups from say 24mm up to say 135mm.  It has worked
well.  My 'vote' is for dual cameras!  You should try to get a dual cable
release, or engage both seperate cables at the same time (pretty easy to
do). The reason for this is that it's best to capture the most identical
images possible so that everything 'looks right' and there is no conflicts
between the pictures (like a branch being higher in one photo and lower in
the other because the wind shifted and the cameras were engaged at different
times.) You can actually get much closer to the subjects and have them "come
out of the stereo window" if they tend to be in the center of the view and
leaning, or pointing, towards the lens... -A very effective "wow" kind of 3D
effect.  As far as the lenses go, if they are both marked 80mm they "should
be " identical enough to not be able to detect differences optically.
However, this may entirely depend upon a manufacturers quality control. My
experience with 6 different lens pairs has been good
(24 & 24, 28 & 28, 35 & 35, 50 & 50, 80 & 80, 135 & 135) and I have not
noticed ANY oddities.  (Hopefully this will alway's be the case?). I think
you are EXACTLY right on the Landscaping flexibility offered by two cameras
on an adjustable platform.  Heck, a platform that is basically 'solid' with
holes drilled through it every 1/2" or so is simple to build without
spending a fortune (like those recent Japanese rigs mentioned earlier) and
do exactly the same thing.  -Good Luck!   -Stuart Johnson
GCSPHOTO@xxxxxxxxxxxxx



----- Original Message -----
From: Bill Glickman <bglick@xxxxxxxx>
To: Medium Format 3D Photography <MF3D.Forum@xxxxxxxxxxxxx>
Sent: Saturday, March 18, 2000 2:23 PM
Subject: [MF3D.FORUM:299] Re: New addition to MF viewer gallery


> I have a few questions regarding MF stereo, any input would be
appreciated..
>
> 1.  Taking stereo shots requires lenses that are identical fl's.  I have
> read that slight differences in fl can alter the stereo effect.  Does this
> mean lens of different fl, such as 80 and 78mm, or can it also mean the
tiny
> differences between two 80mm lenses from the same maker.  Although they
> would be very close, they can still vary slightly... the book did not
> identify how tight lens tolerances need to be.
>
> 2.  My new 6x6 stereo mounts from RMM has one side of image area larger
than
> the other.  Does the larger window side mount closest to the viewer lens
or
> does the smaller window side mount closer to the viewer lens?
>
> 3.  What type of tape is used to tape the mount closed.  I noticed on some
> mounts are taped closed by a silver type tape.... what is this, and is it
> necessary?  If so, where is it purchased?
>
> 4.  Stereo cameras with fixed lens positions are quite popular.  However,
> based on the formula  (1/30) for determining proper lens spacing based on
> subject distance, it seems stereo cameras with 65mm spacing are best
> utilized for shooting close subjects.  If you are shooting subjects 20
feet
> away, it is better to use a dual camera rig in which the lens spacing is
> further apart to as per the forumula.  This of course leaves out the
> variable of both shutters firing simultaneously, which is a photographic
> consideration based on movement.  My question is, is this completly right?
> If so, I imagine a dual camera rig on a slide bar with dual cable releases
> would be the best all around option for shooting a wider variety of
> landscape scenes vs. a fixed stereo camera.  Right?  Were these fixed
stereo
> camera primarily made for protrait shooting?
>
> Thank you..
> Regards
> Bill
>