From: Jeff Kreines (email suppressed)
Date: Mon Feb 18 2008 - 06:31:42 PST
On Feb 18, 2008, at 8:08 AM, Steven Lyle wrote:
> You have confirned by ideas...that is if one captures true frame by
> frame, play-back speed
> is anything you want it to be. True progressive scan digital
> intermediate to film out!
Exactly. Simpler and better. No ties to the old world of telecine.
> Why didn't you use a Geneva movement (with ramped motor speed to
> ease the
> stop and start) and really stop the frame in the gate and scan?
Genevas use sprockets -- a no-no for us. This scanner is designed for
film archives -- there is a lot of shrunken and damaged film in
archives. Our original scanner was built for the Library of Congress
to scan their Paper Print Collection -- pre-1914 films printed onto
35mm-wide paper for copyright purposes. Some of this film had bad
perfs, some had no perfs at all. Using sprockets with torn or
shrunken film is messy unless you have a collection of different
custom sprockets to switch between for different degrees of
shrinkage. Given all the obscure film formats we need to support --
9.5mm, 17.5mm, 22mm, 28mm in addition to the more common ones --
sprockets would be difficult and costly.
With our (patent-pending) perforation readers, we can scan film
that's extremely shrunken or has many torn perfs or missing perfs --
without repairing it first. The film is supported fully across the
face by the PTR rollers we use (6 of them) which clean and drive the
film. The film gates are curved which helps damaged film lie flat.
Tension is adjustable for warped or fragile film.
> With your continuous mode scan tripped by an optical sensor, are
> you sure you
> don't get a *little* motion blur??? Where is you get a scanner that
> can scan 5K
> so quickly??? Wow! No insult intended.
We use a very short pulse of light -- 50 microseconds. Not
milliseconds, microseconds. That's 50 millionths of 1 second. Very
short! But very bright! This has taken years of development, with
many promising technologies proving not-quite-right along the way.
> And what exactly is that frame sensor??? Must be a guarded secret!
> Ha ha!
We use many different sensors -- so far there is no ideal sensor for
all combinations of resolution, bit-depth, and speed -- so we use
various sensors from Kodak, Sony, and some other manufacturers. The
scanner is designed so that one can swap out the sensor head in about
a minute, meaning as better sensors are made it's a simple matter to
upgrade. Many users get different sensors for different uses -- B&W,
color, high-res -- and swap between them as required.
It all looks simple, but it's a lot more work than you'd think, and
Jeff "but it's pretty cool I must admit" Kreines
For info on FrameWorks, contact Pip Chodorov at <email suppressed>.