Mystery 35 film bulk roll.

[mgb74]

Came across a roll of 35mm in an older Lloyd's bulk loader yesterday. I tried developing about a foot of it (unexposed) in D-76 1:1 for 9 minutes; figuring I could read the film code on the edge. I got nothing on either edge. The film itself showed exposure at the end (where it would have been exposed to light in the loader) but even base otherwise.

So is this film unmarked as it appears or did my develop and fix routine fail to make them visible? I would guess that the film is at least 10 years old based on the other stuff with the bulk loader. I could try exposing at different iso settings to dial in an approximate setting, but not sure it's worth the effort for old film.

 

[MattKing]

There are some bulk rolls out there from other than "major" sources that have no edge printing.
If there isn't any likelihood of being able to buy more, I always ask myself the question: "what if it turns out that I like it?"

 

[mgb74]

There are some bulk rolls out there from other than "major" sources that have no edge printing.
If there isn't any likelihood of being able to buy more, I always ask myself the question: "what if it turns out that I like it?"

Which makes it a "no win" situation.

 

[MattKing]

Which makes it a "no win" situation.

I have a feeling though that you might need film from time to time for testing shutters etc. It might be okay for that (once you test for speed).

 

[mgb74]

There are some bulk rolls out there from other than "major" sources that have no edge printing.
If there isn't any likelihood of being able to buy more, I always ask myself the question: "what if it turns out that I like it?"

No doubt there are many, including motion picture films. But any suggestions as to what "almost major" emulsions have no edge printing? I'm thinking the eastern European films (Efke, Forte, Foma) are the most likely; especially if the film is 10-15 years old. I have read online that bulk rolls of the Foma/Arista films did not have edge markings.

I have a feeling though that you might need film from time to time for testing shutters etc. It might be okay for that (once you test for speed).

If I want to use for testing, I need to have a process that yields repeatable results. To determine film speed, I can meter at iso 100, then expose +2 (iso 25) through -3 (iso 800). That part is easy. But what do I use for development data?

For example, using Sprint developer, various iso 100 films can require from 7.5 to 10 minutes. Various 400 speed films can require from 8.5 to 15 minutes. So when looking at developed film, I won't know if development is off or iso is off.

So I'm thinking my protocol (it sounds so much more scientific when I call it a "protocol") is to take 2 sets of +2 through -3 exposures. Using Sprint, develop 1 set for 8 minutes and the other for 15 minutes. If my theory of eastern European film is correct, one (but not both) should be properly developed at "correct" exposure for that iso (ignoring the impact of age of the film, which introduces another variable). If neither "correct" exposure looks right, I can start looking at the over and under exposures.

 

[MattKing]

The film could have a really low ISO. Or a really low EI. I would suggest shooting something like step wedge over a really wide range - EI 2 through 800. Use a middle development time. The initial result should give you an idea about EI, and a feeling about development time. Refine according to taste.

 

[mgb74]

The film could have a really low ISO. Or a really low EI. I would suggest shooting something like step wedge over a really wide range - EI 2 through 800. Use a middle development time. The initial result should give you an idea about EI, and a feeling about development time. Refine according to taste.

That's a good idea; though I'll need to print out a step wedge. But, given that it was in a bulk loader that came with a bunch of darkroom gear, I'd be surprised if it wasn't between iso 100 and 400, and shocked if it wasn't between iso 25 and 800.

 

[Kilgallb]

There are some bulk rolls out there from other than "major" sources that have no edge printing.
If there isn't any likelihood of being able to buy more, I always ask myself the question: "what if it turns out that I like it?"

I recently developed a Delta 100 135-36 roll with no markings at all.

 

[barzune]

Try Diafine.

 

[mgb74]

I don't think I want to invest in Diafine to "rescue" approx 50 ft of expired film.

But I did try my little experiment using Sprint developer. Essentially, treating as iso 100 in exposure and development yielded negatives that where a fit thin. Treating as iso 400 in exposure and development yielded negatives that were a bit better, but still underexposed.

The best frames in this test were for exposing for iso 100 but developing a full 15 minutes as is called for for most of the European iso 400 films (including Arista films) - 15 min in Sprint. As if it was push processed. Next best was exposing as iso 400 and processing as iso 100. As if it was pull processed.

I'm going to try exposing and developing as iso 200 (which I should have done in the initial test).

 

[MattKing]

If EI of 100 is thin, you need to increase exposure (EI of 50 or 25) not decrease exposure (EI of 200 or 400).

 

[BMbikerider]

I do believe some films sold to the Military did not have any edge markings.

 

[mgb74]

If EI of 100 is thin, you need to increase exposure (EI of 50 or 25) not decrease exposure (EI of 200 or 400).

You're right that if exposing at 100 yields a thin negative, I should increase exposure if I keep development the same. I think I'm getting wrapped up in the 2 variables: EI and development times. This next test (at varying EIs) will be at a "middle" time (as you suggested in post 31). I wasn't shooting a step wedge, but was shooting a "contrived" scene with zones II, V, VI, and X (metering on the zone V).

 

[mgb74]

After a 2nd test, this time in D-76 (1:1), I can state categorically that I still don't know for certain. But...

best exposures were at EI of 100 at 8 min and EI of 50 at 10 min. Both showed some evidence of base fog though (keep in mind this is film on unknown age).