Shooting Expired Agfachrome CT100i

[altair]

Hi all. I've just scored some Agfachrome CT100i, expired 1996 real cheap, comes to about USD0.3 per roll. I don't know the conditions they were stored in. I've never shot with this film. My question is, shoot I shoot it rated at box speed or should I overexpose or underexpose and if yes, by how many stops? Do slide films hold up better after expiry than C41 films, with all conditions assumed being equal?

Thanks in advance!

-Dani
KL, Malaysia

[ozphoto]

I'd start by shooting it at it's rated speed and see how it looks after processing. Transparency film is not tolerant to overexposure, but you can underexpose slightly and still achieve acceptable results. I used to use Agfachrome RS exclusively which hated being underexposed by more than 3/4 - 1 stop - any more than that and it would start to shift to a rather unpleasant green.

You might be surprised by the results you get - but don't shoot anything important, just in case it isn't as great as you want it to be. Another option is to cross-process it through C41 - I did some industrial images with this method and the results suited the subject rather well!

[altair]

ozphoto: Thanks all for your reply & PM. I'll do as suggested, shoot it at box speed and see how it turns out. I'll try to post my results here afterwards. Thanks again!

[altair]

Right then, I've shot & developed the roll of this 14 year old expired slide film, rated it at box speed..got it processed for about USD10, and what came out was..nothing! The negs are almost totally blank (not dark though), they just look really transparent. I have to really try hard to see the images on them...they're there on certain frames (the ones with the strongest light), but I'd say 80% of the roll was blank. Really frustrated. Oh well...

Should I overexpose it?

[railwayman3]

I'm not quite with you...are you saying that the transparencies are clear (or almost clear) film (i.e. not dark or black film)?

That would indicate considerable overexposure, which seems odd, I would have perhaps expected the opposite from an old film, i.e. loss of speed.

Is the perforated edge of the film black, and do the edge markings and numbers show normally? If they are OK, that would exclude any processing issues or major deterioration of the film, and you may first need to check your metering, then run a test film at a higher film speed rating, i.e. less exposure.

If the film rebate is clear (and the processing was OK), there is some significant deterioration of the film, or maybe light fogging.

[hrst]

railwayman3, slide films go lighter (DMAX goes up rapidly) when they get old. It's basically the same as fog in C-41 films; if you printed them with the same exposure than fresh film, the prints would be lighter due to fog in film! In chrome films, reversing is done chemically, but the principle is same; fog makes image lighter. This is because there is more silver in the negative after First Development due to fog. No dye will be formed at the silver sites, leading to weaker DMAX and lighter images.

But well, on the other hand, sometimes the Dmin may also suffer (muddy highlights), so, it's not only Dmax.

If the processing is standard, the best way IMO to start experimenting with expired slide film is to shoot normally. If you can modify the process, pull processing (combined with overexposure to get it right) will reduce fog in first silver negative and thus give better DMAX.

It's still surprising not to have any image at all from a 14 year old film. I get usable results from 10 year old chrome films.

[railwayman3]

hrst - I take your point about fog making a slide film lighter...thanks for that explanation, I'd overlooked the effect of reversal. :)

Nevertheless, the OP asked if he should overexpose the film, but if the fogging is already so bad, any additional exposure will just make the matter worse. As you say, some processing modification might help, but I wonder if the film is too far "gone" to be worth spending money on processing costs.

Again, as you say, it seems odd that there are little or no images on a 14-year-old film, which is why I enquired about the rebates or the possibility of light fogging. (I know it's not directly comparable, but I tried out a found 12 year O/D Agfa 200ASA color negative film last year...to my surprise the prints were fine.)