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Topic: optical qualities of nitrate vs acetate

John Schulien
Expert Film Handler

Posts: 206
From: Chicago, IL, USA
Registered: Nov 1999

posted 04-05-2001 02:28 PM

It's conventional wisdom among many collectors that nitrate film had a certain desirable quality -- a look to it -- that was lost when the industry changed to safety film.

However, I've also heard that the main difference between the two types of film is that the emulsion in nitrate film had a much higher silver content.

So my completely hypothetical question is ...

If one were to have a special order made of positive film stock, using the same high-silver-density emulsion as was formerly used in nitrate film, would this reproduce the desirable optical qualities of nitrate film, or is there some additional quality/attribute in the nitrate film base that would still be missing.

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John Pytlak
Film God

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

posted 04-05-2001 02:58 PM

Yes -- silver forms the image in film, even for color films when the silver is fixed out to leave dye. In general, more silver means more speed (for negative films) or the ability to have higher densities (for print films).

Today, Kodak offers two "flavors" of film for release prints:

VISION Color Print Film from Kodak has the same great look you associate
with Kodak films, but blacks are richer, the film is more durable and more resistant to
scratches and dirt.
http://www.kodak.com/US/en/motion/products/lab/2383.shtml

KODAK VISION Premier Color Print Film / 2393. A film with a different look. Richer blacks. More saturated colors.
http://www.kodak.com/US/en/motion/products/lab/2393.shtml

For silver image black and white prints, contrast can be controlled by modifying the process.

KODAK Black-and-White Print Film SO-302 is an ESTAR Base, low-speed,
high-resolution print film. The proprietary, new polyester base of SO-302 improves
physical performance throughout the motion picture system, providing benefits to
archivists, laboratories, exhibitors, creatives, and distributors. It is a cleaner, more
durable print stock with improved sharpness, and has clearer, longer lasting sound
performance. This film continues to offer the process flexibility of previous
black-and-white print films to achieve the desired look.
http://www.kodak.com/US/en/motion/products/lab/so302.shtml

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
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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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 04-05-2001 04:33 PM

John, I have actually seen the difference between Nitrate and Safety with same image comparison. The nitrate looks far better for reasons that I don't know. I saw an I.B. Technicolor comparison at a collectors home a number of years back. I don't think it necessarily has to do with silver or dye content. Something about the optical properties of the Nitrate base itself.
Also, when it is in good condition it is also allot stronger than acetate film ever was or is.
Mark @ GTS

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Jerry Chase
Phenomenal Film Handler

Posts: 1068
From: Margate, FL, USA
Registered: Nov 2000

posted 04-05-2001 05:39 PM

I've seen the difference with black and white nitrate. The crispness of the picture has a noticable improvement over acetate.

I'm in WAY over my head, but I've wondered if some of the following could be factors:

1. Many prints on nitrate were shot with ortho emulsions rather than pan emulsions. The difference in color balance could reduce the blurring effect of the blue portion of the spectrum. This would increase the perceived sharpness.

2. Halation, both during shooting and projection. I don't know the relative refractive indexes of nitrocellulose and acetate, but it could be possible that safety film is more inclined to bounce light around when it gets reflected off the silver image, thus reducing overall contrast.

Those are just top-of-the-head ideas, I'd sure like to know a scientific explanation of the differences.

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John Schulien
Expert Film Handler

Posts: 206
From: Chicago, IL, USA
Registered: Nov 1999

posted 04-05-2001 05:47 PM

Mark -- with IB Tech, remember that Technicolor was constantly changing the dye formulations over the years, so a nitrate print might look completely different than a safety print of the same title for no other reason then that it had been printed using different dyes.

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 04-05-2001 10:34 PM

Everything about a nitrate print, for some reason, has a richer look to it. I've seen both color (animated) and B/W. I've never seen that look in safty films. I would think even the layperson if given an A/B test would go with the Nitrate film as the better image.

Steve

------------------
"Old projectionists never die, they just changeover!"

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Ken Layton
Phenomenal Film Handler

Posts: 1452
From: Olympia, Wash. USA
Registered: Sep 1999

posted 04-05-2001 11:51 PM

Same here. Nitrate is so detailed and sharp with excellent contrast.

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Joe Redifer
You need a beating today

Posts: 12859
From: Denver, Colorado
Registered: May 99

posted 04-06-2001 01:07 AM

Why do all old films look like crap then? With soft focus and washed out blacks and whites? Not to mention oversaturated colors. I hate oversaturated colors. I can achieve the same effect by turning the color waaay up on my TV. I'm not talking print condition, but image quality. Everyone likes to say that things we no longer use or left behind are a hell of a lot better than whatever the hell we are using now. Take records vs CDs for example.

Quality in the old days were always better, right? No matter what we invent in the future, there will always be something in the past that just blows it away. I just think people see a difference and interpret that difference differently.

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Christopher Seo
Jedi Master Film Handler

Posts: 530
From: Los Angeles, CA
Registered: Jun 99

posted 04-06-2001 03:32 AM

John,

That is exactly the same question I've had in mind. I wonder if some country like Russia could still manufacture nitrate base (I have heard that "unique" filmstock such as 16mm nitrate had come out of Russia...). Something else to think about is the optical qualities of acetate vs. polyester, and I know this has been touched on before here.

What is/has prevented film manufacturers from creating black and white films with more silver content? The high price of silver alone?

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John Pytlak
Film God

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

posted 04-06-2001 06:34 AM

I don't think anyone would even allow the use of hazardous nitrate film today in a theatre, even if it could be manufactured and shipped. Only a few film archives are properly equipped and staffed to project nitrate film. Can you imagine a platter full of nitrate igniting? (Look at Rick Shamel's videos of "small" nitrate fires in the "Videos" section of Film-Tech, and imagine 100X the amount of film

The current S0-302 and 5302 B&W print films can be processed to obtain densities well above 3.0, and have more than enough contrast to obtain "rich" blacks and detailed shadows:
Sensitometry of SO-302
Sensitometry of 5302

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John Pytlak
Film God

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

posted 04-06-2001 06:49 AM

I agree with Joe that today's film systems can offer unsurpassed quality. Yes, you can find examples of extraordinary image quality in films of the past, but you can also find alot of grainy and unsharp images with poor color and tone scale. Film technology has improved tremendously, but sometimes the improvements have been traded for the convenience and cost savings of smaller formats, less expensive lighting, speed of production, etc., rather than improved image quality on the screen.

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Jeff Taylor
Jedi Master Film Handler

Posts: 601
From: Chatham, NJ/East Hampton, NY
Registered: Apr 2000

posted 04-06-2001 09:02 AM

When Joe says that all old films look like crap, I think there are two issues. One is certainly the many dye reformulations and color tone changes Technicolor went through over the years (not to mention subsequent reprinting on EK or equivalent stock), but there's also the issue that virtually all black and white prints today are low silver, low contrast prints resulting from TV broadcast requirements and really don't represent the original look of the film.

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John Pytlak
Film God

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

posted 04-06-2001 09:11 AM

Jeff: You are correct that collectors may be basing their judgements on prints made specifically for television syndication. I recall that the recent Warner Bros. and Columbia retrospective 35mm re-releases that recently toured the country were praised for the image quality of the new prints.

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Jeff Taylor
Jedi Master Film Handler

Posts: 601
From: Chatham, NJ/East Hampton, NY
Registered: Apr 2000

posted 04-06-2001 09:19 AM

I suspect it's negligible, but doesn't the fact that older color films were timed for carbon lighting and now shown with xenon have some impact?

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John Pytlak
Film God

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

posted 04-06-2001 09:30 AM

Jeff: High Intensity Carbon arc and xenon arc have very similar color temperature and spectral energy distribution, so it's likely the optimum color timing of the prints would be identical.

But there are some who definitely prefer the "look" of carbon arc on the screen, maybe because it is more of a flame, rather than just a tiny ball of plasma. The lamphouse optics are different, and may affect the "harshness" or specularity of the illumination on the screen.

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