American Cinematographer - August 1983 - 27

Since

projection telecines advance
using an intermittent move¬
ment, they are thought by some to be
rather rough on film. Dave Schnuelle,
chief engineer at Ruxton Video, says
that this is not necessarily the case.
There is, he explains, an important
the film

difference between the movement of
the projection telecine projector and
other intermittent-motion

projectors:
projection telecines
use a sprocket drive rather than a
pulldown claw. The newer projectors
are all sprocket-driven and the
sprocket is always in contact with the
film so you have a good 'wrap.' You
have several holes, contact points, on
''The better

each side of the film and the strain is

therefore more evenly distributed."
Ken Erhardt, who is now manager
of switching central programming at
NBC Burbank, was until very recently

think it's
reason

rougher on film. The main
people feel that the continu¬

manager of telecine operations at the

ous-motion transfer devices

same facility. He has used the TK-29
extensively and has encountered few
film-handling problems.
''There's a popular misconception

on film is that they are very,
quiet. We've never had any prob¬
lems with damaged film at NBC."
It is not the physical threat to the
film that dissuades people from using
the projection telecine with negative
stock, as Dave Shnuelle explains:
''The problem is that it's difficult to

about the intermittent devices," says
Erhardt. ''The noise generated by

stopping and starting film in a projec¬
tor is noticeable and therefore

people

easier

very

are

compensate for the filter mask in
color

negative film," he says. ''I've
on a telecine using Plumbicons and that was transferring 35mm
negative (which is fairly low contrast)
and the dense filter, you've pushed
done it

the Plumbicon to its limits. It's not

re¬

ally intended to do that sort of job."
Bluth Video Systems is another
post production facility in Los An¬
geles specializing in transfer work.
''The TK-29 is not really set up to
do negative work," says Joe Bluth,
company president. ''Many people
think that because it is

an

intermittent

mechanism, it could damage the film.
However, there is no pull-down claw in
(ABOVE) The Videola V-IOOO uses a
hollow prism
which eliminates

flicker in the im¬
age. Interchange¬
able mag heads
permit the use of
either single stripe
three stripe in¬
terlock tracks, and
a
variable color
or

light
permits a
degree of color
temperature

source

correction.

(BIGHT) A rotat¬

ing prism telecine
bv g.t.c. of Ger¬
many designed

for broadcast use
in conjunction
with a conven¬
tional studio cam¬
era which can be

readily removed
for other produc¬
tion work.

the TK-29. The

clacking sound comes
registration mechanism-it
has nothing to do with pulling the film
down. Even though it seems to be
safe to run negative film through it,
the TK-29 is really designed and
intended to be used with positives.
It's particularly good to use with a
heavy contrast print. It has an excel¬
lent gamma range and its black
stretch capability allows you to see
from the

detail in dark
on

other

areas

that would be lost

systems."

THE PROBLEM OF FRAME
RATES

Television systems operate at 60
fields per second and an intermittent
film projector normally runs- at 24
frames per second. During the trans¬
fer, these rates must somehow be
made

ecjual or unacceptable images

will result. The

projection telecine

overcomds this obstacle

by projecting

frame twice, the next frame three
times, the next twice, the next three
a

times and

so on. This means that
each film frame will be projected an

Continued
AMERICAN CINEMATOGRAPHER, AUGUST, 1983

on

page 107
25
American Cinematographer - August 1983

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