[MF3D.FORUM:740] Re: I need a MF 3D Dr.

["don lopp" <dlopp@xxxxxxxxxxxxxxx>]

>From my experience assuming that your Mamyia 7 are 160 mm long, the closest
you can be with 50 mm lenses is 16 feet and 25 feet with 80mm lenses which
amounts to  1:30 for the 50mm and about 1:45 for the 80 mm lenses these
numbers work for me in the past but with my fuzzy methadone mind I might be
all mixed up. Good luck Don.
----- Original Message -----
From: "Bill Glickman" <bglick@xxxxxxxx>
To: "Medium Format 3D Photography" <MF3D.Forum@xxxxxxxxxxxxx>
Sent: Monday, June 12, 2000 11:40 PM
Subject: [MF3D.FORUM:726] I need a MF 3D Dr.


> Hi folks, I just finished my testing.... need help again... just can not
> seem to get stereo images to fuse, when using two cameras following John
B's
> formula.  Here is my problems
>
> 1.  I am using two M7's with perfectly matched 80mm lenses.  When I use
each
> camera seperately and shoot the left and then a right shot with 65mm lens
> spacing it works perfect every time.  True with both cameras.  This worked
> perfectly before Alan modified my viewer and also after he modified my
> viewer, so no change.
>
> 2.   When I use both cameras simultaneously on a slide bar with inter
ocular
> spacing as per John B's formula, I can not get the chromes to completely
> fuse.  I followed the formula to a T...had a tape measure with me, and did
> NOT violate any aspect of the formula or stereo base.  I have the same
basic
> problem...I can not get all subjects in the scene to fuse at once.... it
> seems they will all fuse, but seperately.  I fuse one subject and loose
> another.... then when I fuse certain ones, I start getting the double
edges
> on the left and right again.  (a lot of this double edge image seems to
have
> cleared up after Alan Lewis corrected my viewer lens spacing)
>
> 3.  When mounting the chromes, I notice something odd.... when Paul Talbot
> was here, he showed me the use of the mount gauge.  Setting the nearest
> subject to the near line and furthest to the far line.... Both can NOT be
> satisfied at once with the John B spacing.  (Is this normal? )  And it
does
> not matter if I mount to the near or the far, I still can not get
everything
> to fuse at once.
>
> 4.  Greg Erker advised to take one camera for the left shot and then move
it
> over and bring the other camera in for the right shot, maintaining 65mm
> interocular spacing.  I felt this was an excellent "process of
elimination"
> test.   I did this, and voila it works.  That is why I wonder if the
formula
> could be ill advised.  Here is some examples of the near and far in feet
and
> the stereo base in inches I have been using...
>
> N   F     Base "
> 10  26    6.5
> 10  23    7.1
> 10  20    8.0
> 10  17    9.7
> 10  14   14.0
> 10  13   17.3
>
> Maybe the formula needs tweaking???  I doubted this since so many people
> including David Lee have used this successfully?
>
>     Some basics, I am focussing on identical subjects, same f stops,
> simultaneous shutter firing, I am using a Jaspar engineering 24" stereo
bar
> with built in level, I checked the left / right part of the level with
> another level, it is true, I always level the shot left / right, but
> sometimes tilt the camera down for a scene.   For this test, there was no
> infinity in any of the shots.
>
>     After I concluded that the mounting gauge would not work, I mounted
the
> left chrome and moved the right chrome up and down till things fused
> verticaly, pretty easy to see that.... then I moved the same chrome left
and
> right, and no matter how many places I put it, I can not find one place
> where everything is fused!  I was viewing this over a light box with the
> viewing lenses from my Saturn viewer.  I just removed the lens panel and
> used it for a viewing aid since this would duplicate what I see in the
> viewer.
>
>      One other tid bit they may help someone diagnose my problem.  One
shot
> of a small waterfall in my backyard with larges stones sticking out, (as
> steps for the water falling)  seem to appeared backwards.  In other words,
> instead of the rocks sticking out at you, they seem to be inverted, or
> pulled backwards, like they were indented vs. protruding?  That was
strange,
> but I felt it may provide a clue to solve my never ending mystery.
>
>   I am leaving for a long photo trip and have been trying to get this
worked
> out for the past 6 weeks but just keep failing.  Any input would be
greatly
> appreciated.  Thank you all.....
>
> Regards
> Bill G
>