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Re: Pin registered prints



>Is anyone here experienced in the ways of registered print and the
>Adam gate?  Is my encounter unusual?
>
        Most of my experiences have been bad...
        We had the original Steadi-Film gate at Action Video and I have had
three Pin-Up installations (Action and Post Logic.)
        Steadi-Film relies on the slight natural cupping of normally
oriented negative in the stripper plate. As the film is lowered onto the
stationary pins, the outer edges should fall first so the resistance of
slipping over the pins is countered by the rest of the mass of the film
coming down. Picture holding a sheet of paper flat - by just one edge. The
stripper plate does not actually push the film down (you wouldn't want
that, would you?) but does rely on a mysterious combination of film cup,
tension and inertia. Positive film always wants to cup the wrong way- the
center of the film comes to rest first and the edges of the film can only
be pressed onto the pins by the tension of the film. You can't put enough
tension on the film to make this work over successive frames.
        Some negative has other distortions that get ironed out after a
trip thru the ultrasonic cleaner which restores the normal cup and allows
the system to work. I believe that is mostly due to the effect of
stabilizing the moisture content of the roll. I even had one registered,
optical negative roll that wanted to cup the wrong way that just wouldn't
work. We reversed the roll head to tails and flopped the picture as needed
to produce the required cup direction of the film. Steadi-Film enables this
by allowing you to reverse print to get the frame order right.
        Positive film can be had with "negative perfs" as you know.
Sometimes the pitch is longer but the designer of Steadi-Film did allow for
a mode of advance that avoided accumulating a pull forward error. I don't
know if this made it into the Adam model or not.
        Pin-Up (by Video Engineering) handles emulsion up and emulsion down
with no real difference. Interpositive, negative and positive film all lies
flat on the skid plate after frame advance. As the pins are brought up, the
initial alignment of the sprocket holes to the pins is the most important
influence on the final seating of the pins. That doesn't mean the Pin-Up
system is flawless, it just doesn't have the dependency on emulsion
orientation that Steadi-Film does.
        Pin-Up has an adjustment that can fine tune for off pitch film
stock but a properly set up system (mechanical and electrical) will handle
the difference between negative pitch and positive pitch film without
intervention.
        BTW, how come you can't achieve the positive look required by the
client with all that horsepower? (Un-called for dig of a colorist by an
engineer!)

--- David Tosh  dlt at earthlink.net  (CIS 72167,1376)