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Re: CBS high def test



> "Super-16
> looked like home  movies, with a lot of noise and dirt presence," says CBS
> engineering VP Bob Seidel. "But the high-definition camera and the 35mm were
> almost indistinguishable--the high definition actually had a little better
> resolution than the 35mm."

I would like to make a few comments about the CBS test described above.
I was involved from the beginning in the development of the experimental
Kodak HD telecine, which became the FLH 1000, which became the Philips
BTS Spirit Datacine. I was involved in a great deal of testing including
the transfer of all formats of film, including Super 16, to HD on these
machines. While working in Europe, I wrote a paper on Super 16 film
production and HDTV which I gave at the IBC and the SMPTE conferences.
For anybody who has seen some of the Kodak demos we produced on the FLH
1000, one can attest to the fact that there is a clear difference in the
"look" between 35mm film and HD camera origination. Film has a superior
look on HD for conveying fantasy, adventure, and drama type programming
as has been supported in another note. The FLH 1000 and Spirit telecines
can produce a flawless transfer to any HD standard. When film is shot at
30fps for 1125/60, you also eliminate the 3:2 pulldown artifact. The
resolution difference seen by CBS may be coming from the 3:2 artifact.
The dynamic range of film and the way it captures and gracefully
reproduces the highlights in the shoulder and the shadow details in the
toe of the film is unmatched by any HD camera.

On the topic of 16mm film for HD production, I came to the following
conclusions from the telecine tests we conducted. First, 35mm film
production was clearly superior to Super 16 film production for HDTV
programming due to grain, sharpness, and steadiness advantages. However,
Super 16 can work quite well on HD if handled properly. Second, don't
even think about shooting regular 16. You need the 40+% additional
imaging area of Super 16 for HDTV. Third, you need to avoid high-speed
stocks. Eastman 7245(EI 50), 7248(EI 100) and even 7293 (EI 200) make
quite acceptable pictures in HD when tranferred on a high-quality HD
telecine. But the high speed stocks, like Eastman 7298 (EI 500), are
unacceptable for grain and sharpness in HD. I wonder if the CBS tests
were done on high-speed stock as most teleproduction is done. If one
knows in advance that their Super 16 originated programming will end up
on HD, they need to use the slower speed stocks. Also, the film needs to
be handled gently and as little as possible prior to transfer to reduce
the chance of picking up any dirt or scratches. In Super 16 HD
production, these are quite noticeable due to the high magnification. 

Finally, the HD telecine itself is one of the most critical factors in
making acceptable HD transfers from Super 16 film. The telecine faces a
tough challenge from an imaging system that has a small image area and
an edge-guided transport system. To make it all work requires the best
cameras and raw stock physical quality (slit edge, support flatnesss,
etc.) The telecine must have a good edge gudiance and servo system. It
must have an extremely sharp but fast lens to insure that the MTF of the
film original is translated efficiently through the system. The telecine
must also have a high S/N to insure that the noise that it seen on the
monitor is coming from the film and not from phosphor noise or other
electronic sources.

The transfer of Super 16 film to HD puts a significant challenge to any
telecine design. Since I am no longer working for Kodak, I can tell you
that I believe that the Spirit Datacine is probably the only HD telecine
which can accurately transfer the fullest quality of Super 16 film to
HDTV. If CBS wants to get a true reading on what Super 16 film can do on
HDTV, I strongly recommend reshooting the test on fine-grain color
negative stock at 30 fps in a good S-16 camera and then transfering on a
Philips Spirit Datacine to HD.

Sorry for my long, first note on the TIG but I had to make these
comments.
-- 
**********************************
* Brad Hunt                      *
* All Post, Inc.                 *
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