slide film shelf life

[wilson]

how long do you think e6(velvia) or the like wold still be usable after its expiration date. I'm sure alot of you have seen this guy on ebay who has a never ending supply of expired slide film. I was browsing today and it has got me wondering.

sorry if this is old news. I searched this forum but found no answers satisfying.

thanks for any insight

wilson

 

[railwayman3]

I just don't think that you can get a totally definitive answer on this one.

Any film is guaranteed by the manufacturers to give a result "as good as fresh film" up to its expiry date, if kept as instructed (usually just reasonably cool and dry).
Clearly they will allow a good margin in this, so the film will still be totally usable for all general photography for some time after the expiry date, certainly months and perhaps a year or two.
Refrigerating and especially freezing will increase the life considerably, up to several years, but common sense is needed and older film would need a test before use......you are out of any guarantee and obviously manufacturers are not going to advise you of how deterioration will affect the film after expiry. They've done their bit by giving you a reliable expiry date.

Turning to Ebay - as with most of Ebay, you pay your money and take your chance, since there is no guarantee of the storage conditions of the film...lots of film sold on Ebay is "said" to have been frozen, but who knows?
You have to accept that all you can do is to buy some of the film and test it before using for anything important.

Having said that, I've bought an occasional brick of o/d E6 film from Ebay, tested one film, found it good and used the remainder of the film within a few weeks while it was OK. But I'd always pay the extra for fresh film for photoshoots like a daughter's wedding or holiday-of-lifetime!

 

[srs5694]

Refrigerating and especially freezing will increase the life considerably, up to several years, but common sense is needed and older film would need a test before use......

I'll add this: AFAIK, there are basically two causes of deterioration of unexposed film over time: chemical changes in the emulsion and exposure-like events caused by radiation (including cosmic rays). The chemical changes can be slowed substantially by cold storage, but radiation -- and particularly cosmic rays -- will continue to affect film no matter what. There really isn't much you can do to protect film from cosmic rays, since not even lead stops them.

This is relevant because the speed of film affects how quickly it deteriorates from cosmic rays. Thus, all other things being equal, you'll get a longer useful cold-storage life from a slow film (say, Velvia 50) than from a faster one (say, Elite Chrome 400).

 

[reellis67]

I've gotten E-6 film (E100G specifically) from an eBay seller that sounds similar to your description which has been anywhere from 6 months to a year or so out of date and not had any problems, but as stated above, when in doubt, expose some and verify the results. For important things I use fresh film, but for a lot of things the savings of buying short-dated or expired makes sense, at least for me. Interestingly enough, for black and white film I always buy fresh, and it's less likely to have problems with age than E-6.

- Randy

 

[wilson]

damn cosmic rays. It's always somethin'.

 

[Craig]

I've found the original Velvia 50 to be very tolerant of being used past it's expiry date. I used some 8x10 Velvia that was 10 years past date and it still looked good, and didn't seem to suffer any observable loss of D max in shadows.

However, I'd bought it fresh and kept it in my deep freeze at -20 the whole time.

 

[yellowcat]

Slide film does have a shorter shelf life than neg film but I have had good results from cross processing outdated slide film.