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RE: filmscanners: My replacement 8000 is banding like the first one :-(
Polaroid scanners use the 'worm screw' design for the fine movement of the
carrier. It is one of if not the most expensive components. It is then
further calibrated by software in the manufacturing process so any anomalies
can be adjusted for.
David
-----Original Message-----
From: Arthur Entlich [mailto:artistic@ampsc.com]
Sent: Saturday, July 21, 2001 5:44 AM
To: filmscanners@halftone.co.uk
Subject: Re: filmscanners: My replacement 8000 is banding like the
first one :-(
Lynn Allen wrote:
>
> Given: That the stepper mechanism is accurate, and not just a piece of
> trash...
> Then: It would not matter whether the copy is moved or the scanning head
is
> moved.
>
I don't fully agree. One can design a very precise metal screw or other
method for moving the CCD head assembly, in an enclosed unit internally
which could be kept clean and lubricated.
Moving the film via a carrier, which is likely molded plastic, with
plastic gearing, and also having it need to "mesh' with the motorized
transport, and being that the carrier is prone to dust and dirt
attraction and "the elements", makes it much harder to maintain
integrity of precision movement.
In the case of the HP-S20, the film was moved via rubber tires, which
would both wear and tend to slip over time, and not be very repeatable.
Now, something that truly amazes me is that on several occasions I have
run a print through my Epson printers several times to overprint to make
color and exposure corrections. Tonight I sent a print through six
times, as an experiment to see if I could build up density and make
subtle color alterations. The darn thing is perfectly registered even
after six run throughs. The only defect I see is from those "pizza
wheels" which after six times, have made quite a series of sprocket
holes into the print in a few locations. The print otherwise almost has
a Ilfo/Cibachrome-like quality to it, after all those ink layers.
Art
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