longevity of color film negatives

How can I increase the longevity of color film negatives? I intend to develop (C-41) color negatives in the near future. (I have done this in the past and have some experience.) Can I increase the longevity of the negatives by doing an ordinary additional fixing after I have completed the other steps in the C-41 process? If not, is there any way to increase the longevity of the negatives?

Can I increase the longevity of the negatives by doing an ordinary additional fixing after I have completed the other steps in the C-41 process?

 

I don't think so. The process should be pretty much complete when done according to spec.

 

I think that the comparative lifespans are mainly dependent on the specific dyes used, and that your best bet would be to go with a professional grade film from a major manufacturer.

 

That aside, storage conditions are very important. Heat is bad, as is high humidity. For info on storage see Henry Wilhelm's book, available for free download from his website.

 

The book is now pretty well outdated, but did have information on films of that era. I don't think you'll find much other info on modern films.

Color film is comprised of organic dye imbedded in gelatin. This is the structure of the film emulsion. Organic dyes are fugitive, longevity is reduced if chemical contaminates are present Also, longevity is recued if the pH and temperature and humidity are hostile. Life beyond 100 years is unlikely. Additionally, the gelatin binder of the emulsion is made from animal bone and cartilage. As such, the emulsion is fair game for mold, fungus and other beasts. The last step of the process is a stabilizer. Its job is to neutralize residual chemicals of the process and to apply a mild biocide.

 

All you can hope to do is correctly process per specification and store in a low humidity cool environment.

Thanks guys. I'll stop worrying about it. I am using kodak portra 400 &160 film and kodak pro image 100. The portra is, of course, a pro grade film, not so sure of the pro image 100 tho, despite the 'pro' in the name.

Wilhelm Imaging Research literally wrote the book about preserving film and prints. Here is a

 

LINK WIR: Table of Contents

 

One good way to keep color negatives is cold storage.

How long are you thinking of storing those negatives?

 

I have colour negatives from C-22 process days, and before that, that are still printable. They've had no cold storage nor been locked away in a humidity-controlled safe. They've just been kept at room temperature in glassine sleeves in a folder. In short they've simply been kept (mainly) in the dark and protected from dust and air pollution.

 

With sensible storage 50 years should be easily doable. There may be a little colour shift in that time, but nothing that can't be got back in a scan, since I doubt there'll be many working darkrooms around in 50 years time, and even less likelihood of RA4 (5, 6, 7, 93?) colour printing paper being obtainable.

Edited April 21, 2020 by rodeo_joe|1

Ten to 25 years is plenty long enough for me and I always have to scan the negatives if I want to print the positives.

I've found color negatives to be much less forgiving in long term storage than positive transparencies. I still have color slides my father took in the late 1930s which look good (highly saturated, but that I think was the nature of Kodachrome) today, whereas many of my color negatives from the 1970-80s have experienced dye "shifting" or deterioration...both under similar storage conditions...low humidity, room temperature and darkness,

I still have color slides my father took in the late 1930s which look good (highly saturated, but that I think was the nature of Kodachrome) today,

But that was the main selling point of Kodachrome; its dye stability. If you compare colour negatives with coupler-incorporated films like Ektachrome or Velvia, you'll find that those reversal films generally fair worse over time. However, this might have something to do with being card or plastic mounted. Such slides usually get stored in a box exposed to much more air, rather than pressed in archival sleeves.

 

Whatever. Kodachrome is the gold-standard of dye stability, and comparing it to any coupler-incorporated film (neg or pos), is an unfair, apples to oranges, comparison. Likewise, comparing a Cibachrome print to a standard dye-coupler print isn't a fair comparison either.

Edited April 22, 2020 by rodeo_joe|1

Yes Kodachrome has been the standard for many years, but as well as I know, newer coupler-incorporated

films are at least as good, and likely better, than old Kodachrome.

 

As above, temperature and humidity are most important. People in tropical countries, or tropical

parts of other countries, which includes much of the southern US, should be careful. If it isn't

too warm and humid for you, it is probably not so bad for the film.