Filmbase + fog question

[naaldvoerder]

I have not been shooting enough the last couple of years. Other things of live got in the way. Now I find myself with quite a collection of rolls of film that is grosely out of date. I am in the process of assessing what is still sort of usable. Now I would like to hear if anyone of you could give me a sort of figure of base + fog, measurement against the carrier of the film, that would make curtain films sort usable. I am particulary interested in FP4, HP5 en 3200Delta. In other words above which value for base+fog do those varieus type of film become useless.
I know the obvious rspons to this type of question. Buy new film.. And I already did. But I would like to know what of all the film I collected over the years could be of some use. Thanks.

Jaap Jan

 

[Doc W]

I might be wrong, but I think that you would test the film in the same way as any other film. The fog will likely be higher with older film but you still need to establish the exposure index that will give you Zone 0 at 0.10 above base + fog.

 

[Sirius Glass]

Use the old film. If you are not experiencing any problems great, otherwise use new film for those times when you cannot afford to have a problem.

 

[Chris Livsey]

Don't forget that as well as a fog increase the film will have lost some speed as well.
I would do a clip test of the old film and a clip sample of the new film on the same developing reel, so developed to same standard and look at the base+fog density comparison, you could do the same with a standard exposure of both to a middle tone to assess any speed drop.
If you have access to a densitometer so much the better but I suspect a visual check will tell you all you want to know.

 

[Huub]

How old is old? When less then 10 years old i would not expect many problems with FP4+ and use it at its nominal rating of 125 iso, HP5+ i would rate as 200 iso and develop as normal. A bit of overexposure doesn't harm this film and will help you printing through the fog. The Delta3200 will be the most critical and probably show heavy fog, possibily up to a level where it can be tossed.

 

[Andrew O'Neill]

How old is the film? I have several boxes of 4x5 HP5-Plus that I have had stored in the freezer that were bought fresh in 2005 and expired in '07. I've just started using them this past summer, and according to my densitometre, they have gained about .10 in density... I also have some Kodak IR film that expired in '67. The fog is quite heavy, equivalent to about 2 stops exposure. Still very printable. If you kept the film frozen, you will be fine.

 

[cmacd123]

there does seem to be a almost linear effect that the higher the Initial speed, the faster and more devastating the age defects are. I asked Ron the photo engineer about this but My knowledge of what happens was not able to ask him a question that he could explain to me.

General rule that I might draw is anything B&W under about ASA 125, little or no visible problems up to 10 years in the open, or 20 years in the freezer. ASA 400 is showing some deterioration after 10 years in the freezer. and the P3200 style films start showing problems after 5 years frozen or not.

My observation to ron was that I got the impression that after a while two rolls, say one Plux-x and one Tri-X after 10 years, the plus x might have a higher useful ASA than the Tri-x. BUT of course I woul dneed more samples and a much more consitant test plan to verify this.

 

[Doc W]

there does seem to be a almost linear effect that the higher the Initial speed, the faster and more devastating the age defects are. I asked Ron the photo engineer about this but My knowledge of what happens was not able to ask him a question that he could explain to me.

General rule that I might draw is anything B&W under about ASA 125, little or no visible problems up to 10 years in the open, or 20 years in the freezer. ASA 400 is showing some deterioration after 10 years in the freezer. and the P3200 style films start showing problems after 5 years frozen or not.

My observation to ron was that I got the impression that after a while two rolls, say one Plux-x and one Tri-X after 10 years, the plus x might have a higher useful ASA than the Tri-x. BUT of course I woul dneed more samples and a much more consitant test plan to verify this.

Good to know. I have Plus X and Super XX in 4x5 and a box of Tech Pan in 8x10, all of which is long in the tooth, so thanks for the info.

Do you think that living "beyond the fringe" contributes to the longevity of the film? Only another local (Glebe) would have got such a kick out of your signature, and no one else here knows what we are talking about. Some of us just had the first Ottawa APUG pub night. Let me know if you are interested in the next one.

 

[RalphLambrecht]

I might be wrong, but I think that you would test the film in the same way as any other film. The fog will likely be higher with older film but you still need to establish the exposure index that will give you Zone 0 at 0.10 above base + fog.

Doc is right but it's only worth the effort if we're talking a lot of film;otherwise,I would just expose at box speed and give it normal development;it may be a bit flat but nothing a harder grade of paper cannot fix

 

[Andrew O'Neill]

I prefer .11

 

[Saganich]

For trix I get between 0.24 and 0.27 on the 'ol macbeth. FP4 a little higher at 0.28 to 0.33. Varies a bit with developer. My experience with old film was there was no question it was bad.

 

[Doc W]

Pardon me, Doc, but I think you mean Zone I is at 0.10 above fb-f. [Reference: AA's The Negative, pp. 88 and 242].

I stand corrected! Well, I am sitting, but you get the point.

Thanks, silveror.