[MF3D.FORUM:1173] Re: First roll run through the mystery Whutnikstereo

[Greg Erker <erker@xxxxxxxxxxxxxx>]

>5) The lens matching came out this way (lens focal length matching):
>   a) I first calculated it by measuring the shims that Mamiya had used
>at       the factory. One lens had shims, the other didn't.  I assumed
>that       this equalled the f.l. difference between the lenses, and
>then the       calculation came out to a .66% mismatch.
>   b) On the roll of film I measured a vertical feature on each of two
>L&R       images (using a loupe optical comparater).  The calculation
>came          out to .64%.

  Sounds good. Thanks for sharing.

>One subjective note: This .66% mismatch between lenses is very good in
>my opinion.  It does not affect the stereo image at all.  I had a
>mismatch greater than this on my first Yashica camera project that was
>used for my entries in the ex-Joel folio circuit. Did anyone notice a
>problem with those images?

  I found 0.35% mismatch to be visible when mounted
if there is detail at the top and bottom of the window.
If you line up the bottom details then the tops are
cut off slightly differently. So I shimmed my one lens
out to reduce the size difference to 0.15% or so.

  I'll agree that on an image with blue sky at the top
you wouldn't have a problem mounting or viewing .66
or even 1% different sized images.

>An interesting note is that I had already run through a roll of Kodak
>print film (I sacrificed it so I could study the film transport with the
>camera open).  It did not have any problem with pulling through the
>camera, even with that spring in place and the back closed.
>It was when I used the Fuji Velvia slide film that it got very
>difficult.  I can notice a difference in the friction value of the paper
>backing.  The Fuji paper has more friction than the Kodak paper it
>appears.

  Hmmm. Almost like Kodachrome sliding through
a Realist easier than E6 films.

Greg E.