How long do Chromogenics last?

All my analog photography friends told me that I should be shooting traditional B&W film for real negative archival quality, since I've been shooting mostly chromogenics like Kodak's BW400CN and Ilford's XP2 Super. My question is, how long would negatives from a chromogenic film last, compared to the 150+ years from a real B&W negative? I've seen C-41 color film negatives degrade in terms of color quality, but chromogenics is somewhat different from normal C-41 film.

Yeah - well, I guess you (probably) won't get color splits... the way you do with color stuff. But - I'd imagine it'll start getting magenta after 10-15 years...

Two main variables: who made it and how it was processed.

Ilford once described the XP series as 'black and white with colour couplers added' and Kodak's equivalents as 'colour films with the colour taken out'. How much this matters, I don't know.

Much more importantly, to my certain knowledge, a well-washed XP2 will last for many decades, but a lot of mini-labs don't wash it, just stabilize it. I have XP-series films from up to about 20 years ago, and some are funny colours and others aren't. Ilford tells me that water-washed XP2 should remain printable without loss of quality for many decades.

The figure of 150+ years is optimistic for any acetate-base fims (including almost all 35mm), as the film base is likely to deteriorate before that except under ideal storage conditions. Polyester bases (including all modern LF film) should however last as well as glass.

Cheers,

R.

I think that the life of any film or negs depends largely on the storage conditions, and no doubt the processing as well. Properly stored color lasts a very long time too. I have some color movie films taken by my dad in the early 1940's. The colors have probably faded a little, although I wasn't around to see them when fresh. Otherwise they are pretty good. These would be over 65 years old, Kodachrome I suppose. I have Kodachrome and Ektachrome slides I took in the late 60's- early 70's that are a mixed lot. I processed some myself, using small kits. These were not Kodak chemicals, I seem to recall Ansco? Maybe Agfa. The slides I took myself have not fared as well as those processed professionally. The professionally processed slides still look good (well, at least they don't seem to have degraded). Black and white should be even better in storage.

The dyes produced in chromogenic materials have improved enormously in the past few years. Twenty-five years ago, color negative film would start color shifting after about ten years. Now, it seems to be good for at least 30 years, and some say it's good for 70 years. From the data available, Kodak black and white chromogenic materials seem to have dyes very similar to their color film products. I would expect them to be quite stable. I have no information about the Ilford product. If it is built the same way, I would expect a similar life. If it uses black dyes, the life may be a bit shorter. (I base this on the relatively poor life of the black dyes used in the chromogenic black and white papers that used to be available. If may be incorrect.) Of course, color stability is not much of an issue in a black and white negative, so long as sufficient density remains to give a good print.

Kodak has published a paper for long term storage of their chromogenic films. If stored properly you can completely arrest any degradation and their films will last indefinitely. In general, the colder the temperatures the longer the dies will last, but keep in mind storage for each film may vary so beware. The Kodak publication numbers are E-30 and E-107.

Ilford's XP2 chromogenics have been around for this long? I thought Chromogenics is a relatively new type of B&W film. All my C-41 B&W are processed by 1-hour labs, since there's no way for me process any B&W or C-41 film currently. How easy is it to process chromogenics if I want to do so in the future?

Roger Hicks said:

Much more importantly, to my certain knowledge, a well-washed XP2 will last for many decades, but a lot of mini-labs don't wash it, just stabilize it. I have XP-series films from up to about 20 years ago, and some are funny colours and others aren't. Ilford tells me that water-washed XP2 should remain printable without loss of quality for many decades.

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film_guy said:

Ilford's XP2 chromogenics have been around for this long? I thought Chromogenics is a relatively new type of B&W film. All my C-41 B&W are processed by 1-hour labs, since there's no way for me process any B&W or C-41 film currently. How easy is it to process chromogenics if I want to do so in the future?

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About 25 years, maybe a little longer. The first came from Ilford and Agfa. Agfa soon dropped theirs but XP1 became XP2 became XP2 Super, which should have been XP3 but apparently some of their US marketing department were afraid of confusing their customers -- how stupid did they think we were?

Chromogenics are easy enough to develop in a CPE-2 or similar but the very short times at high temperatures (100C) are hard to master with a small hand tank; conventional films are easier. I also find it easier to dry conventional films clean.

Why can you not process film? All you need is a changing bag and a kitchen sink.

Cheers,

R.

Roger Hicks said:

[...] which should have been XP3 but apparently some of their US marketing department were afraid of confusing their customers -- how stupid did they think we were?

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You'll be amazed to learn that those who think they are smarter than most are irrelevant in terms of product marketing. In fact, I've learned in a couple of occasions that they are irrelevant in politics as well.

Chromogenics are easy enough to develop in a CPE-2 or similar but the very short times at high temperatures (100C) are hard to master with a small hand tank; conventional films are easier. I also find it easier to dry conventional films clean.

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I think you meant 100F or 38C, which is not too hard to maintain just for 3m15s. However, it's easy to use 27C/77F and still get excellent results (the time has to be adjusted). It can be done easily in spiral tanks as well. More of a problem is that color developers are phenylenediamine derivatives and you want to be more careful in handling them.

I'm not certain about the kind of couplers that went into XP1, XP2 and XP2 Super. Generally, paper products use couplers that make more stable dyes (when combined with paper developers) than film materials. It is only recently when Fujifilm started applying stable couplers from color paper to color film. Astia, Velvia 100, etc. were the first products using this technology. The "new" Velvia 50 is going to be back to the old technology, though.

I have some XP2 from 1990s and although I didn't do densitometry on them I think they are thinner now (still printable). Some AGFA and Kodak color negatives from same era is also slightly faded or slightly color shifted. All these are still prefectly printable. I scanned them and take very little effort to adjust them digitally as well. Conventional b&w from the same era is still in perfect shape.

Not all modern sheet films are made on polyester. Some (if not many) color films still use acetate film base, even in sheet sizes. This is probably because there is no point in using more expensive material if the color dyes fade in a few decades.

Ryuji said:

I think you meant 100F or 38C, which is not too hard to maintain just for 3m15s.

Not all modern sheet films are made on polyester. Some (if not many) color films still use acetate film base, even in sheet sizes. This is probably because there is no point in using more expensive material if the color dyes fade in a few decades.

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You are of course absolutely right. Sorry for any confusion caused.

Cheers,

R.

Is it practical to re-wash mini-lab film, or does the stabilizer cause a problem?
Mark

Mark Layne said:

Is it practical to re-wash mini-lab film, or does the stabilizer cause a problem?
Mark

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Dear Mark,

I have re-washed XP2: a 5 minute soak, a shake, a rinse, then an Ilford wash sequence (3 changes of water, inverted 5-10-20 times respectively). But I've not had the re-washed film long enough to know how much good this does. Mike Gristwood, when he was at Ilford, said it should work OK.

Remember to ask them to leave the film uncut, loosely rolled (I give them clean 8x10 neg bags to put the rolls in). Otherwise they'll often cinch them into a 35mm film canister.

Cheers,

R.