The traditional procedure for transferring 24fps film to PAL video is to run the film through the telecine at 25fps, so the film runs slightly fast and 1 frame of film = 1 frame of video.

By contrast, an NTSC transfer has to fit four frames of film into every five frames of video. This is normally achieved by a 3:2 process as follows:

In each set of 5 video frames -

video frame 1, fields 1 & 2 contain film frame 1
video frame 2, field 1 contains film frame 1
video frame 2, field 2 contains film frame 2
video frame 3, field 1 contains film frame 2
video frame 3, field 2 contains film frame 3
video frame 4, fields 1 & 2 contain film frame 3
video frame 5, fields 1 & 2 contain film frame 4

So frames 2 and 3 in each set of 5, have their two fields split between two adjacent film frames.

Therefore the contents of the 20 fields in a sequence of 10 video frames looks like this:

1 1 1 2 2 3 3 3 4 4 5 5 5 6 6 7 7 7 8 8

So every second film frame occupies 1.5 frames of video.

Isn't technology wonderful?

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Ray Derrick
President/Chief Engineer
Panalogic Corporation Sydney, Australia
Phone: 61 (0)2 9894 6655 Fax: 61 (0)2 9894 6935

However, I believe that the bottom line will come down to who will pay the price at the box office.

I do not believe that the majority of the audience cares whether the medium is film or video. They want to be entertained, they want to forget about their problems for a few hours by watching a show and being engrossed in another world of problems.....somebody else's.

I think that doing film right is a wonderful service that the public appreciates. If you are showing video, do it "right" also.

Both of these mediums are going to have to co-exist for a long period of time. I believe that e-cinema will eventually win the lions share of the market, I also believe that film as an art form will never disappear.

So my question is, if film can't do perfect black (or can it?), why is digital video held to a higher standard?

(Where I used to work, we had a JVC/Hughes D-ILA projector in the company's product demo room, and it looked pretty darned good. Don't count out D-ILA. It was for demo'ing video games, but we frequently showed DVDs on it after-hours and it was pretty impressive [but not film].)

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- dave
Crab juice, or Mountain Dew?

Digital Cinema standards are still being developed by the SMPTE DC28 working groups, so there is no "higher standard" today. For film projection, standard SMPTE 196M specifies that "Screen luminance due to stray light shall be less than 0.16% (600:1 theatre screen contrast ratio) for review rooms and primary theatres."

Kodak VISION Premier color print film can achieve densities well above 4.0, which represents over a 10,000:1 brightness range on the film. However, the negative must be well exposed to achieve shadow densities and "blacks" this rich. Often, prints with "smoky" or "milky" blacks are due to underexposure when shooting the camera negative, which is often a deliberate artistic decision on the part of the cinematographer.

Here are data for Kodak VISION Print films:
http://www.kodak.com/US/en/motion/products/lab/2393.shtml
http://www.kodak.com/US/en/motion/products/lab/2383.shtml

FWIW, after a Digital Cinema screening of "Planet of the Apes", I was able to cast a distinct shadow on the screen with the light from the DLP-Cinema projector that was projecting "black", so there's room for improvement.

Yeah film black can be pretty black (what was that process called that left some silver in the print in order to get the blacks more opaque?) CRTs (projection or direct-view) can achieve good blacks as well. LCD and D-ILA still have a ways to go. Same for DLP though not as much--can't wait to see the new black DLP 1920x1080 chips. Other than "make it look like film" I'm not aware of any quantifiable standards for the level of black in a theater application (I'll defer to other SMPTE folks here). Picture black should just barely be discernable from whatever background light level exists in the room. When I do video I insist on having no lights on in the video engineering area. That way when I set the black level on the match monitor I can achieve true beam cutoff for picture black--it don't get any blacker than that. Since there are lights on in the rest of the production facility, the blacks on the monitors in those areas end up being set a little higher.

Hurray to Bob for anchoring this back to the ultimate purpose of our endeavors--entertaining an audience! Now if only the studio suits would greenlight more stories worth telling...

Cheers!

Paul
Workin' on gettin' back to SoCal or Japan

Technicolor calls it "ENR". Deluxe Labs calls it "CCE" or "ACE". Others call it "bleach bypass" or "silver retention":
http://www.theasc.com/magazine/nov98/soupdujour/pg2.htm

Leaving some silver in a color print image does make the blacks more dense and increase contrast and graininess, along with desaturating colors. One disadvantage is that the silver absorbs infrared energy, making the print more prone to heat damage or focus flutter with very large or misadjusted lamps.

As I noted, Kodak VISION Premier Color Print is capable of over 10,000:1 contrast range in the NORMAL ECP-2D process --- that's REALLY black!

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John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

http://www.gekco.com/vidprmr.htm#SMPTE%20Bars
http://www.mrli.com/gallery/html/smpte.html
http://www.videotek.com/app27.htm
http://www.leaderusa.com/assets/images/ch8.pdf

Smoky blacks in Digital Cinema displays are most likely due to flare in the optics or stray light, which a "blacker than black" signal will not correct. Ideally, if the signal is "black", you should not be able to cast a shadow on the screen. In reality, there is often noticeable light coming through the lens.

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John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

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The principles outlined in my article on "Conquering Contrast Killers" apply to both film and digital projection:
http://www.kodak.com/US/en/motion/newsletters/reel/december99/pytlak.shtml

The "bottom line" test is whether you can cast a distinct shadow in the "black" areas of the projected image. The "blackness of outer space" is NOT supposed to be dark gray.

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John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

The SMPTE color bar pattern is chalk full of goodies though (kinda like 35-PA is to film)...with a minimal amount of "tools" (an blue filter) one can set color, tint and brightness. As one gets to know the pattern, even the individual colors can be detected to be off.

Steve

Many people are dissatisfied with the present SMPTE PLUGE pattern--it's in a corner and it's too small. Several years ago I had heard there was a recommendation going around the SMPTE Working Groups to change the pattern. Haven't heard anything about that lately.

Cheers!

Paul
SMPTE Hollywood Section
Workin' on gettin' myself back to SoCal and Japan