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Topic: How fast are reels printed on high speed printers?

John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000

posted 03-23-2006 08:46 AM

Timing/grading of the cut negative is usually done using an electronic color analyzer, that displays a positive image of the negative, and allows the color timer to see the effect of any changes in printer exposure (printer "points" or tape values). The cut negative is then actually printed to produce an "answer print" for approval of the director and cinematographer, and additional small changes are made to finalize the scene-to-scene color and density.

After the final scene-to-scene timing has been approved by the filmmakers, the timing information is used to make a master positive on a film like Kodak VISION Color Intermediate Film, most often with a wet gate additive continuous contact printer (e.g., a Bell and Howell Model C printer with a Schmitzer gate at about 180 feet per minute). Short-pitch duplicate negatives for release printing are made from the master positive, ideally on a pin-registered step printer.

Before final release printing, "check prints" are usually made for final approval of the color timing and continuity of the release prints. Many times, this is directly compared to the approved timed answer print to verify that everything was done correctly. If necessary, additional small scene-to-scene changes could be made during high speed release printing (done using additive printers), but this is rarely necessary.

Most laboratories use the Kodak Laboratory Aim Density (LAD) system (which I developed), or a variation of it, to control the color timing and duplication process. Here is a link to information about LAD:

http://www.kodak.com/US/en/motion/support/lad.jhtml?id=0.1.4.15.8.6&lc=en

quote:
Laboratory Aim Density (LAD)
In the Laboratory Aim Density (LAD) printing control method, a standard control patch specifies densities midway between the minimum and maximum of those typically obtained for a normal camera exposure. These specific densities have suggested tolerances for each film type in the duplicating and print system, and are listed in this publication, along with helpful hints for their use and evaluation. All color films in a production, regardless of film type or origin, are timed with respect to the LAD control film. Each frame of LAD control film, having the standard patch, with proven accurate exposures plus other information, is available from Eastman Kodak Company.

Here is an interactive tutorial about the "Imaging Chain" for film duplication:

http://www.kodak.com/US/en/motion/support/imageChainDetect.shtml

And tutorials about printing and other laboratory operations:

http://www.kodak.com/US/en/motion/support/h1/dealing.shtml

quote:
Dealing With A Laboratory
Tips on Selecting a Laboratory
Laboratory Services: a Walk-Through
Laboratory Operations
Technical Assistance From Kodak
Motion Picture Film Cleaning
Motion Picture Printing

And a Handbook from the Association of Cinema and Video Laboratories (ACVL), that Dominic Case helped write:

http://www.acvl.org/acvl_manual/index.html

quote:
Published by The Association of Cinema & Video Laboratories, Inc., the ACVL Handbook exists to acquaint users of motion picture laboratory services with terminology, pre-print preparation and procedures which are standard in the industry.

The film laboratory plays an essential role in the transition from conception of story, plot or theme to the finished product -- the motion picture film. In carrying out this function, there must be teamwork and understanding between the producer, the director, the cinematographer and the laboratory so that the finished product will be of maximum quality, interest and effectiveness.

Now in it's Fifth Edition, the ACVL Handbook offers recommended procedures for motion picture and video laboratory services.

With modern duplicating stocks and techniques, almost all of the image qualities contained in the answer print are in the release prints. This is checked on a regular basis when the answer print is directly compared to the check prints.

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Dominic Case
Expert Film Handler

Posts: 131
From: Sydney NSW Australia
Registered: Aug 2003

posted 03-28-2006 06:00 PM

The benefit of a timed (colour corrected) interpositive and dupe negative is that you are using the best part of the characteristic curve to record the tonal range of the image.

The IP and DN stock has a very long straight line portion - so if both stages are exposed correctly by the lab (using the LAD system that John describes), then the full range of tones from the original negative can be reproduced with no alterations. However, by putting the colour correction in at the first stage, you are clearly positioning the tonal range optimally on the IP and then the DN stock, as well as removing the need to do it later. Scene to scene light changes can be done on any printer, but not at high speed.

Also of course, once the grading is locked in, the scene-to-scene balance, and the "look" of the film, is locked in too. Negatives sent to other labs for international release prints will produce the desired results without the cinematographer having to approve a new grade.

Carl's theory about normally exposed negative intended to be printed down is one of those things that was probably true of earlier generations of emulsion, and may still be true if the IP and DN aren't made to exactly the right standards: but otherwise it's no longer a problem. Still, old wisdoms are hard to kick off.

Applicator splashes aren't a risk in high speed printing but in high-speed processing. Something else that is now (at last) becoming a thing of the past.

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Carl Martin
Phenomenal Film Handler

Posts: 1424
From: Oakland, CA, USA
Registered: Feb 2002

posted 03-29-2006 05:45 AM

dominic,

thanks for addressing my question more directly. and for the term "characteristic curve".

i was thinking of timing mainly as the process of giving a certain look to footage properly exposed, like in godfather (for which timing at the last stage seems more ideal), while you focus on bringing footage that perhaps wasn't perfectly shot back into the middle of the characteristic curve (which should ideally be done earlier rather than later--sounds reasonable). i guess it's unrealistic to hope for two timing stages. too bad more prints can't be made off the o-neg.

i do all too often see prints that just look like mush and have no shadow detail whatsoever. from what you're saying that's not due to high-speed printing per se. so that leaves...

1) "the IP and DN aren't made to exactly the right standards"
2) digital intermediate: another reason to hate those.
3) artistic intent
4) indifference

is it your opinion that (1) is a fairly rare occurence? maybe it varies a lot by lab?

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John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000

posted 03-29-2006 09:39 AM

"Lost shadow detail" is most often due to underexposing the original negative, and is likely to vary on a scene-to-scene basis. If the "curve placement" onto the master positive or duplicate negative was grossly wrong, the entire reel would have an issue. In my experience, since the development of LAD to help labs in the early 1970's, this has rarely been a problem. As Dominic notes, best practice is to use the scene-to-scene timing determined in making an answer print to make a timed master positive --- Kodak VISION Color Intermediate Film has more than enough latitude to fit all the scene information on the "straight line" portion of the sensitometric characteristic:

http://www.kodak.com/US/en/motion/products/intermediate/5242.jhtml?id=0.1.4.6.4.4&lc=en

quote:
For the filmmaker, these intermediate films help to preserve all the sharpness, clarity, and color of the original images and carry them more faithfully to the final display screen.

For the laboratory, VISION Color Intermediate Films enable the production of printing elements that are closer in quality to the look of a print made directly from the original negative.

Postproduction facilities will appreciate the features of the VISION Color Intermediate Films, especially improved sharpness for digital output. They're the choice for production of masters for theatrical re-release, video and DVD release, satellite, cable or broadcast TV presentation - or use in any media of the future.

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Dominic Case
Expert Film Handler

Posts: 131
From: Sydney NSW Australia
Registered: Aug 2003

posted 04-03-2006 08:44 AM

quote: Carl Martin
1) "the IP and DN aren't made to exactly the right standards"
2) digital intermediate: another reason to hate those.
3) artistic intent
4) indifference

Well that pretty much covers all possibilities! Though as John points out, underexposed original negative is another cause of muddy blacks in prints - though that would be rare to happen throughout a production.

Most labs that handle studio feature work follow the same recommendations for duplication - and the stock works very well when those standards are followed. Obviously I can't speak for them all though. Similarly with Digital Intermediates: when set up correctly, the results are superb. If you've seen DIs that give you reason to hate them, then they aren't typical of good DIs. It's still newish technology though, and the results aren't as consistently good as they could be: sometimes though, this is as much to do with overambitious artistic intent as with technological imperfections. Again, the DI process brings wonderful benefits to a film when used correctly: it shouldn't degrade the results.

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