P3D Re: ISO Super Duplex - Questions

[Paul Talbot <ptww@xxxxxxxxx>]

Dr. George A. Themelis wrote:

> My new ISO Duplex Super 120 arrived yesterday!  (...)

> Questions:  How many pairs should I expect to get from the 120
> roll?  Do I advance frame after frame as they are marked in the
> film? (there are two windows you can read the back of the film)
> I just shot one roll and got 12 pairs.  Does that sound right?

I have never seen one of these cameras, but I haven't seen anyone
else answer yet.  So I'll ask some questions about what you found
out so far.  You say it gives 23x24 images side-by-side on 120
format film, and you got 12 pairs.  120 film normally yields 12
2-1/4" (approx 55mmx55mm) images, so if your images were only
24 mm high, did you have a large amount of unused space (vertically)
between the pairs?

Does the film run vertically or horizontally through the camera?

If vertically, it sounds like there should be room for 24 pairs.
You said there are two windows.  Do they line up with the center
(12-frame) sets of numbers on the 120 film backing?  If so, my
purely WAG is that you should advance the film only one-half of
a frame after each shot.  If the two windows are about 30mm apart,
it should work out nicely.  Just start with (1) in the first window;
advance until (1) is in the second window to take the 2nd shot;
advance until (2) is in the first window for the third shot, etc.

If the windows line up with one of the off-center sets of numbers
intended for another format, it might be possible to advance 40%
of a frame each time, so that the 24x24 images are placed on the
film with no vertical spacing.  I'm not familiar enough with the
other roll film image sizes to advise how the progression would
work under this arrangement.

> Seems that the aperture is controlled by a square aperture
> blade.  This does not seem right (...)

I can't even begin to guess on that one, so someone else needs
to step up to the plate!

Hope this proves helpful.

Paul ("gets it all wrong") Talbot, going out on a limb


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