Film-Tech Forum ARCHIVE: Nitrate vs. newer stocks

This is topic Nitrate vs. newer stocks in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Adam Fraser (Member # 1074) on 05-31-2002, 09:37 PM:

I was looking through some old intro's and stuff in the attic at our theatre. Some of them might date pretty far back as they are stored in small metal film cans in an old metal film safe. I was wondering how you can tell the difference between nitrate and newer film stocks as some of these might be getting near the nitrate date. Theatre built: 1941

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Adam Fraser
www.pinestheatre.com

Posted by Gordon McLeod (Member # 33) on 05-31-2002, 09:54 PM:

Look at the edge area
If it doesn't say SAFETY FILM it is safeer to assume nitrate
If that is the casew
cut a 2" piece and hold it with needle noise pliers outside well away from ny flamable object
Ignite the upper most corner
If it burns DOWNWARD with a bright yellow falme the offs are 99% it is nitrate

Posted by Steve Kraus (Member # 476) on 06-01-2002, 09:46 PM:

In later years nitrate stock actually said NITRATE on the edges.
This chart might help you determine when the film stock was made, in case you are curious. The date codes are no longer used on Kodak stock, having been replaced with a directly readable date.

Posted by Adam Fraser (Member # 1074) on 06-01-2002, 11:22 PM:

Thanks guys, better safe than sorry

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Adam Fraser
www.pinestheatre.com

Posted by John Pytlak (Member # 331) on 06-02-2002, 09:51 PM:

Here are links to NITRATE info on the Kodak website:
http://www.kodak.com/country/US/en/motion/hse/safeHandle.shtml
http://www.kodak.com/country/US/en/motion/support/technical/storage3.shtml
http://www.kodak.com/country/US/en/motion/support/technical/storage1.shtml

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: +1 585 477 5325 Cell: +1 585 781 4036 Fax: +1 585 722 7243
e-mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Posted by Josh Jones (Member # 447) on 06-02-2002, 10:36 PM:

Can freezing nitrate films lenghten or halt decay?

Josh

Posted by John Pytlak (Member # 331) on 06-03-2002, 05:51 AM:

Reducing the temperature of storage slows any degradation reaction. But I don't know of any nitrate-certified refrigerators or freezers for home use. (I certainly would not want to store nitrate film in the same refrigerator used to store food).
http://www.kodak.com/US/en/motion/support/technical/storage3.shtml#nitratea

Posted by Steve Kraus (Member # 476) on 06-03-2002, 11:11 AM:

Send it all to me; the Fourth of July is coming.

Posted by John Pytlak (Member # 331) on 06-04-2002, 08:05 AM:

Steve said: "Send it all to me; the Fourth of July is coming."

Seriously, if you find nitrate film, DO NOT PROJECT IT, even if it appears to be in good shape. Even if your theatre originally had a nitrate-certified booth, it's likely some of the required safety equipment has been removed or disabled. To reinforce the danger, take another look at Rick Shamel's nitrate fire videos in the "Videos" section.
http://www.filmpreservation.org/basics_nitrate.html
http://www.clevelandclinic.org/act/frames/chp3/chp3_1.htm

If the film is in good condition and you can identify the content, contact some of the established film archives to see if they are interested in preserving the material:
http://www.amianet.org/11_Information/Information.html
http://www.geocities.com/soho/square/5632/nitrate.html

If a film archive wants the material, they will work with you on how to properly (legally) package and ship the film to meet all (DOT) regulations.

Posted by Steve Kraus (Member # 476) on 06-04-2002, 06:02 PM:

Oops...I've been bad.

Then again it was only 30 ft or so.

Posted by Leo Enticknap (Member # 534) on 06-05-2002, 05:55 AM:

In reply to Josh and John P, reducing the temperature of nitrate film certainly inhibits (but does not arrest) decomposition, but humidity is important too. As a general rule, the colder and dryer the better (and that goes for other forms of decomposition too, e.g. Eastmancolor fading and deacetylation). The International Federation of Film Archives Preservation Committee recommend the following for nitrate:

Temperature:
4°C (39°F) +/-1°C on a daily basis
4°C (39°F) +/-1°C on an annual basis

Humidity:
50% +/-2% RH on a daily basis
50% +/-5% RH on an annual basis

[Source: FIAF Preservation Commission, Preservation of Moving Images and Sound, 1st ed., September 1989, p. 24.]

Domestic fridges can certainly deliver the temperature, but judging by how often I need to switch mine off to defrost it, I'd guess that the humidity is way above 50% RH. Freezing film elements for preservation is done by some archives, though (not many because of the cost). For example, the Imperial War Museum in London freezes original colour elements to inhibit dye fading.

Another British example is the Mitchell and Kenyon collection, some 800 reels of nitrate dating from the turn of the last century, which were kept by their owner in (I've been told) domestic deep freeze units until the British Film Institute recently acquired them and started to make polyester preservation dupes. The quality is stunning.

But no, I wouldn't want to keep nitrate in the same fridge as my food, either. Quite apart from anything else, all those off-gases would make the beer taste pretty horrid...

Posted by Jeff Taylor (Member # 443) on 06-05-2002, 11:41 AM:

If you do come across nitrate material which is not deteriorated (i.e.curled, brittle, or even "gooey") and feel it may have some value, Jeff Joseph of Sabucat Productions has the knowledge and appetite to deal in the stuff. Contact him through Sabucat on the net at www.sabucat.com

Posted by Leo Enticknap (Member # 534) on 06-06-2002, 11:20 AM:

Sorry - an afterthought on this thread, should have remembered earlier. Gordon writes:

quote:
Look at the edge area If it doesn't say SAFETY FILM it is safeer to assume nitrate

But if it says 'safety' do not automatically assume that it isn't nitrate, especially if you can see both 'nitrate' and 'safety' (or 'S') marks between the perforations and the edge of the film. It is possible for footage to be originated on safety negative stock, or duplicated through safety intermediate stock, and then printed onto a nitrate release print. This is especially true of newsreels, where portable cameras were often used which needed to be taken into places where nitrate would not have been safe (e.g. on aircraft or other enclosed spaces). It also holds true for 35mm feature film elements used around the time of the conversion process (roughly 1948-52), because some cinema chains held out for nitrate, requesting nitrate prints from exchanges and labs, until the base was completely withdrawn. This was because they still believed that nitrate was significantly more durable than the new triacetate. So again, a film originated on safety negative could have had nitrate release prints made.

Safety film was used quite a lot for pre-print applications, most notably newsreel shooting, long before 1950 - the diacetate and acetate propionate stock available then was a lot more expensive and less durable than nitrate, so it was not used unless there was a special reason, but it was used.

Posted by Leo Enticknap (Member # 534) on 06-08-2002, 04:48 AM:

Going through some files last night, I found a 1950 leaflet produced by Gaumont-Kalee for training projectionists how to differentiate between nitrate and safety.
Click here