Little help with old film. Question about the emulsion matterial!

[Rhodes]

A friend of mine is scanning several old 35mm films in the Municipal photo archive section, of the city museum. He is having difficulty in founding information about the emulsion type, if they are nitrates or acetates. The films in question are:

Agfa Isopan F, Isochrom F, Isopan S.S. (I.S.S) and a Perutz film.
The date of the rolls is 1938, but not sure if 1938 is the production date. They can be older.
Mainly they have a dark grey colour and show little signs of deterioration.
Do to the date, I think they are nitrates, but I could be wrong.
Is there any site with more detail information about the agfa films, when they change from nitrates to acetates, etc?
What I know is the basic information, about during the 50s the transition to acetate and from 1955 there were no more production of nitrates films.
Any help is appreciated and grateful of course.
Thank you!

 

[AgX]

The most easy and fast way to get that information about the base would be to test a snippet of those films:
Combustion test and spec. density test, the latter being the most precice.

At least the Agfa ones have Nitrocellulose base.

 

[Rhodes]

Thank you. Yes, I know, but that's a no go, do to the fact they do not want to cut any piece of the film for that kind of tests.

 

[AgX]

Then they have to live with the uncertainty.

I do not see a problem with cutting off a snippet of the rebate. Such attitude rather indicates ignorance of archival practice.

The conservative way then is to consider any film in doubt as having a NC-base.


As you know reliable information on this topic is scarce. And even film with the same designation might have undergone a substitution of base without further indication.

 

[pdeeh]

There is good clear information about identification, handling and management of nitrate film in the following locations:

http://www.kodak.com/global/en/corp/environment/kes/pubs/pdfs/H182.pdf

http://www.amianet.org/groups/committees/nitrate/documents/NitrateIGNov08.pdf

 

[Rhodes]

I understand that, but that section is a bit untypical in certain matters. Also, they do not have the required chemical and they tend to have a protective policy in their material. Many 35mm films are identified as nitrates, the ones I have ask are the uncertain ones.
And of course, only with a reliable test can one have certain.
I found some info about http://www.klauskramer.de/nitrofilm/nitratfilm_top_04-09.html but the listed films, do say partly partly nitrate, partly safety film!
I find that it is best they treat all has nitratres, just for the safe.
Thank you again to both!

 

[AgX]

Concerning my own ignorance:
I do not know of a single case where still film, not bulk-spooled stored, caused an incident. I would appreciate to learn about known cases.

 

[gone]

Instead of holding to a match to a tiny snip of film outdoors to see if it's nitrate, they'd rather store whole rolls that might be nitrate? How smart is that? I know of no other way to 100% know what they have. Any and all online info on the film would not be a sure bet. Only if you found the exact printed material that matched up to what you have would that be possible, and even then, test it. That is just common sense.

 

[Gerald C Koch]

Since companies stopped making nitrate films in the 1950's I would have to assume that film made in 1938 was on nitrate stock. There is a non-destructive test. A solution of diphenylalanine and sulfuric acid will turn nitrate film deep blue.

 

[Rhodes]

As Gerald says, they assume that it is because of the date and store it according. The film material comes from a old photographer shop, that began in the latte 20's until 1958.The owner bough the material from an retirement photographer to began his work.
That's why there is no certain in the date of production of the rolls I ask. For what I saw, they look like nitrate 35mm film, but they only have printed the brand and model. No Nitrate word on it.
But I do not know if every 35mm nitrate film had that printed.

 

[AgX]

Nitrocellulose base was the standard, thus there was no reason to name it.
Alternatives long time suffered from disadvantages. Thus next to the safety benefit there also was reason even not to indicate a substitute.

 

[Rhodes]

Exactly!
I saw a few LF and MF negatives from the same collection. Several 5x7 and other sizes, dated from 1929 forward, didn't have Nitrate written. And several others negatives had the safety film.

 

[Jim Noel]

When 35mm and other roll film was first switched from a nitrate base the words "Safety Film" were printed on the rebate.

 

[AgX]

Would it be so in any case.