Agfa CT18 deterioration

Jao

Jao

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I have recently been going through my ancient transparency archive with a view to digitising some of them. Many of the slides shot on CT18 have a distinct purple cast that was not there a few years ago! In terms of age these are from about 30 years old and shot in my late teens. My kodachomes and Ektachromes from the same period are absolutely fine.

Has anyone else experienced this with Agfa CT18 slides in their archive?

I suspect when I get a slide scanner I will be able to correct some of the cast out but I am interested to hear if this is common?
 
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I don't have any personal experiance of this but a quick google of "Agfa CT18 slides purple cast" bring up several hits with others having similar problems.
 
Thanks David, I'll have a bit of a search.
 
Darn it! Better dig my Agfa slides out for a look.

Thanks for the warning.
 
Such a shame. Needless to say, scan them in as quickly as possible and hope that the PP can recover the damage (which shouldn't be too difficult).
 
From what I can remember, the process that Agfa used before about 1980 was very different to all other reversal processes (a kind of 'Agfa Kodachrome' so to speak) and because of that its likely that the dye fading prevention technologies developed in the mid 70's to 80's and which revolutionised colour film life were not applied to it as they stopped production in 1978 and their processing service in 1981.

Kodachromes would not fade because they contain pure azo dyes which take a long time to degrade and around that time Ektachrome was in a state of continuous R&D by Kodak so it would have contained the latest film technology being destined for the professional market such as the stability technology above.

All you can really do now is create high quality scans and burn them to good quality CD's etc and if possible limit further damage to the slides by cold storing etc.
 
Mine look ok but then the oldest are from 1984.
 
Des, glad that your CT18s are ok. Might be worth planning to get them scanned while they are still in a decent state.

Samuel, your post is helpful in that it sheds some light on that state of my slides. Looking back and estimating the date of the majority of my CT18 slides they are between 1978 and 1979.

As you say the best I can do is get them scanned to the best quality I can and save them in a secure place.

As an aside, the reason I shot CT18 at the time was that I could buy it for quite a bit less process paid than I could Kodachrome. That has proved to be a bit of a false economy. Lesson there for me, all be it. 30+ years later!
 
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I bought a range of Minox cassettes 2 of which have shot film in them. I had vague thoughts of trying to process them in b&w chems. One of the cassettes is marked CT18.

An internet search brings up this (old!!) thread. So it's an old slide film that requires development in an obsolete process. It's answered my processing thoughts - unfortunately, don't bother. It's gives me another plastic Minox cassette to use though so that's good!
 
MIGHT still be worth souping in some B&W chems. I'll leave it to someone more au fait with the film to tell you whether you'll get anything and (of course), someone else's old shots on a tiny format might not be worth the effort anyway!!!
 
That post is a blast from the past! Sadly my CT18s have deteriorated further since I made the post. I believe there may have been an issue with some of Agfa's processing at their plant as I know others with CT18 slides which are just fine decades on. Anyway, to the question at hand. CT18 was developed using Agfa's Process 40, which is unlike modern E6, indeed Agfa abandoned Process 40 with the rise of E6. It is worth googling Process 40, because I'm aware some people did home brew this process. It wasn't like Kodachrome, where the chemicals were simply too dangerous. Back 2017, I had a random conversation with an American when we were both in the Carmancita lab in Valencia collecting processed C41. He was home brewing Agfa processes for CT18 and CT21, sadly I've lost his details. Alternatively as @Nod says you could just experiment with a general purpose Black and White developer
 
@Jao - certainly a thread resurrection and a half :)

As both you and @Nod say it might be worth it. I've got some nearly exhausted, nearly expired ID-11 I could chuck at the CT-18. I won't make that my sole developing session but have it souping in the background. I've already got an ancient shot colour film in a dev tank just to keep it out of light whilst the original cassette has been reloaded with b&w and is in my Minox. I'll see.
 
Jao said:
I have recently been going through my ancient transparency archive with a view to digitising some of them. Many of the slides shot on CT18 have a distinct purple cast that was not there a few years ago! In terms of age these are from about 30 years old and shot in my late teens. My kodachomes and Ektachromes from the same period are absolutely fine.

Has anyone else experienced this with Agfa CT18 slides in their archive?

I suspect when I get a slide scanner I will be able to correct some of the cast out but I am interested to hear if this is common?
Click to expand...

Yes, my old slides fro the late seventies on Agfachrome have lost a lot of colour and have a strong purple cast. My Kodachrome and Ectachrome slides are still as perfect as the day I shot them. I made some copies with my D850 with slide copier attached, and was able to recover a little colour.

I was in my first job living in London with little spare cash for photography. Agfa slides were cheaper than Kodak

DSC_4825 3.jpg

This was about the best I could do. So I converted to monochrome.

DSC_4824.jpg
 
excalibur2 said:
Well I've used Agfa slide film about 1968 to 1978 and slides kept at room temp and the colours have deteriorated, but not that far gone, the scans I took, couldn't be revived in Photoshop.
e.g.
https://imgur.com/l6ufUZj
View: https://i.imgur.com/l6ufUZj.jpg
Click to expand...
Brian, your have survived much netter than mine, which have been stored in a temperature and moisture controlled cabinet. I believe CT18 in particular is the film that has the 'Curse of the purple cast'. I'd be delighted if mine looked like your example.

NCV said:
Yes, my old slides fro the late seventies on Agfachrome have lost a lot of colour and have a strong purple cast. My Kodachrome and Ectachrome slides are still as perfect as the day I shot them. I made some copies with my D850 with slide copier attached, and was able to recover a little colour.

I was in my first job living in London with little spare cash for photography. Agfa slides were cheaper than Kodak

View attachment 390754

This was about the best I could do. So I converted to monochrome.

View attachment 390755
Click to expand...

Nigel, exactly the same experience, my Kodachromes are still great, but my Agfa CT 18s are all now pretty dire. I was at school in the late 70s and the money from my Saturday job in a camera shop, could really only run to CT18 including my staff discount!, It was considerably cheaper than Kodachrome and Ektachrome when you added in the developing. It was even cheaper that CT21, which seems to have faired better in terms of deterioration, even though the film used the same Agfa Process 40 chemicals! I'm in the process of moving from my trusty Plustek 8100 scanning regime to a D810 scanning stand and will re do the CT18s , probably more for nostalgia than quality!
 
Kodachrome has always had the reputation of being the least susceptible slide film to fading etc. That said, my Kodachromes of the 1987 hurricane aka Great Gale are a mixed bag. All have been stored under identical conditions, but some have a purple cast. "Identical" so far as they were in the same filing cabinet, non identical in so far as they occupy different hanging wallets.
 
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StephenM said:
Kodachrome has always had the reputation of being the least susceptible slide film to fading etc. That said, my Kodachromes of the 1987 hurricane aka Great Gale are a mixed bag. All have been stored under identical conditions, but some have a purple cast. "Identical" so far as they were in the same filing cabinet, non identical in so far as they occupy different hanging wallets.
Click to expand...
Strange as my Kodachromes are OK and are kept mounted in the circular Kodak cassette in the original cardboard box.
e,g, taken about 50 years ago
https://imgur.com/bIdAxO3
View: https://i.imgur.com/bIdAxO3.jpg
 
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