[MF3D.FORUM:526] Re: Exact fl match for paired lenses.

["Bill Glickman" <bglick@xxxxxxxx>]

I tested my paired 80mm Mamiya lenses, and from the outcome, it seems to
have been an expensive mistake.  I promised I would report in my results...

The first problem I have is the lenses centers are 5" apart when both
cameras are mounted next to each other on the slide bar.  This was my first
experience shooting at this base seperation.  The results were poor.  When I
mounted the chromes I learned why this practice is risky... you can not
prevent double vision on the side edges.  Although I must admit the center
looks awesome.  But the whole effect is destroyed by the double vision on
the edges.    I assume this is simply the consequence of having a base wider
than it should be..  It is possible to get the base in a bit tighter by
mounting the cameras vertical.... it would be cumbersome and only help a
bit... it will not accomplish the 65mm base required.

Next I took some shots with subjects further in the distance.... I used John
B's formula...and I still had the same problem... probably because there
still was some near subjects in the scene, like grass.  It increases the Wow
effect on the far subjects but somehow everything else does not look right?
Has anyone else experienced this?

My conclusion is this.... mounting two cameras side by side on a stereo bar
is a very difficult thing to accomplish.  Not many cameras fit together like
Greg Erkers do.  So this prevents you from shooting any subjects which are
near.  Moving subjects therefore are limited to greater distances only, due
to the wider stereo base.   Timing the shutters is very hard to accomplish
with two cameras, many variables exist in this... however, with a bit of
fine tuning, this is poosible to get close.... if the subject is not moving
too fast, it should be OK.  The wide stereo base does not seem to produce
images as pleasing as the normal stereo base.... although I did not
experiment on the Grand Canyon where I am sure it would.   Focussing the
cameras perfectly in sync is also difficult and time consuming.

I also experimented with using a shorter fl lens, 43mm using the 65mm stereo
base.  This once again did not create the realism the 80mm lens did?  I
guess our brain is wondering why the scene is so damn wide???    our eyes do
not see like that!

after this experiment, it surprises me that the Gilde MF stereo camera is
the only new camera on the market today... but at $12k for the camera and
one pair of stereo lenses, its just a bit pricey for my taste.

Unless someone offers me some great advise, my MF stereo dreams are drifting
away.... It seems the best I can do is shoot with one MF camera with one fl
lens, and simply move the camera between shots on the stereo bar.  This
eliminates all motion shots.... even trees blowing in the wind just a bit,
right?

Maybe I am making some mistakes or overlooking something major?  I am worn
out and have exhausted my 3d knowledge....  Any input would be helpful, at
this point, I'll even accept a pat on the back.... and a "Nice try" remark
:-)

Bill G