Re: 220 headaches

Yeah, that's all I should have done, but I continued
on trying to do something different.

http://uptowngallery.org/Murray/220filmin120camera/
has a 6x6 chart and 6x9 chart based on my 6x4.5
results. I can't find that one....it's with a camera
somewhere.

There is also a sheet 220-120.jpg that you may need to
print out to read (8.5 x 11). It has some of the
useful and useless spreadsheet effort. The beginning
has data taken from the ANSI spec for 220 film. AGFA
Cst. Svc. sent me a pdf doc & I can't find that
either.

Based on what Guillermo noted (film tightness, etc.),
and paper/film length tolerances, you can't calculate
it precisely.

You can also see from my charts that trying to reduce,
for example say a 13 mm/half-inch space between frames
or to get even spacing just isn't going to happen.
Even if you had a precise correspondence between
frames and turns, you can't measure the turns
accurately enough to correct a couple mm of length. I
put a 0-100 volume control (330 degrees or so) dial
plate from an old radio under the GOST film scale
screw on the Moskva and didn't want to subdivide any
smaller than 1/8 turn.

Maybe my charts or someone else's answer will allow
you to proceed with more confidence and less
guesswork. I think the best one can expect is not have
light leaks and to just enjoy the modern or
not-so-modern-soon-to-be-extinct convenience of nearly
doubling the number of exposures you can get.

If anyone has the 220.pdf ANSI spec I forwarded,
'you're "it" '.

Murray

--- Guillermo <penate@rogers.com> wrote:

> ----- Original Message -----
> From: "Murray Leshner"
> <murrayatuptowngallery@yahoo.com>
>
> >...this is still entrenched in length per turn and
> > not turn per length,
>
> Murray,
>
> If you have "length per turn", just divide 1 by
> "length per turn" and you
> will have "turns per unit of length". For instance,
> if 1 turn give you
> 0.5", dividing 1 by 0.5 will result in 2, meaning
> you need to turn 2 times
> to advance a length of 1". Another way of seeing it
> would be: if 1 turn
> give you 1/4 the length of a frame+whatever gap you
> need in between frames,
> dividing 1 by 1/4 would result in 4, meaning you
> need to turn the advance
> knob 4 times to advance to the next frame.
>
> But math is really not the way to go this time,
> progressively each turn of
> the knob advances more film than the previous one,
> this could be accounted
> for in a calculation, but unfortunately if the film
> is not really tightly
> wound around the take up spool, your math
> calculation will be off the mark.
> I would make a mark on the advance knob and another
> on the camera
> symbolizing "home position" from which to start
> advancing each roll, then
> I'd mount a roll, and with the back open start
> advancing it frame by frame
> (making marks on the film) and I would also add a
> wider gap between frames
> (for safety). After each frame+gap is advanced, I
> would then make a mark on
> the camera just in front of the mark on the knob and
> label it "1" (as in
> frame 1), keep doing it until the end of the roll.
>
> Guillermo
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Received on Sat Aug 6 14:12:47 2005