Very odd problem with Foma 400 bulk roll

[Paul Howell]

A few months back I bought a bulk 100 foot roll of Foma 400. The first rolls all came out well, E.I, 320 to 250 depending on the camera and developer. I used Acufine, Diafine at 320, D76 and HC at 250. Then the roll seems to have lost 2 to 3 stops of speed. At first I thought my developers were just getting old, toss the developers, then thought my camera was off. I had been using a Minolta 800si, then I used a 600si, and today Minolta X700. I am now using Clayton F76+, a roll of Foma 200 came out spot on, the roll of bulk loaded Foma 400, 2 to 3 stops off. I shot at 250, developed for 8m at 68 degrees 1:9. After I doubled checked the X700 with my Gossen meter, spot on. The bulk load in well within date, never had such an issue. Tommarow I going to shoot a ring around with a large test chart and see what ISO it is acutally shooting at, best guess at this point is 50.

 

[boring old man]

I could believe a faulty thermostat could cause ripening or finishing temperatures to be too low, and cause the emulsion to be lower speed (or too high and create fog), but I wouldn't expect it to change mid roll. Even if emulsions are added to the coating hopper mid coat, I would expect the film to show multiple speeds, and I don't believe there's a way to load backwards and shoot through the AH layer. Do you have a roll that looks properly, and then under exposed? Even if the film did transition between emulsions, I doubt you would cut the film at exactly the transition spot, or that it would be dead straight across the base.

 

[mshchem]

My thought is to check camera with a roll of something else like Tri-X or HP5, factory loaded cassettes. Use a fresh factory developer too.

These new fangled E-lectronic cameras can't be trusted.

Sunny 16 some of it in manual.

 

[Paul Howell]

My thought is to check camera with a roll of something else like Tri-X or HP5, factory loaded cassettes. Use a fresh factory developer too.

These new fangled E-lectronic cameras can't be trusted.

Sunny 16 some of it in manual.

I did with a roll of Foma 200, it came out fine.

 

[Paul Howell]

My thought is to check camera with a roll of something else like Tri-X or HP5, factory loaded cassettes. Use a fresh factory developer too.

These new fangled E-lectronic cameras can't be trusted.

Sunny 16 some of it in manual.

I will use a Konica T with 50mm on manual with a Gossen SCB meter. I have fresh bottles of Clayton F76+ which is single use, both the Acufine and Dinafine were replenished and were getting a bit long in the tooth, although in the past I've had replenished Dinafine going for a year.

 

[mshchem]

I did with a roll of Foma 200, it came out fine.

 

[mshchem]

I will use a Konica T with 50mm on manual with a Gossen SCB meter. I have fresh bottles of Clayton F76+ which is single use, both the Acufine and Dinafine were replenished and were getting a bit long in the tooth, although in the past I've had replenished Dinafine going for a year.

 

[mshchem]

I wonder if Foma spooled the wrong stuff?

 

[koraks]

Then the roll seems to have lost 2 to 3 stops of speed.

Not a chance. This is some form of user error; the tricky bit is figuring out what happened exactly.

 

[Raghu Kuvempunagar]

Just a wild guess. By any chance were the speed-loosing rolls spooled such that the base faces the lens when loaded into the camera, as one would do for redscaling of colour films?

 

[Agulliver]

I cannot begin to think of how a standard B&W film like Foma 400 could lose 2-3 stops in a short time. It's hardly the world's most advanced film but it's reliable stuff.

Are you bulk loading into DX coded cassettes? Are you using the DX coding? I am not familiar with the cameras you mention so I don't know if they detect DX coding but it strikes me that could be one error if the cassettes are not coded correctly, or of the contacts in the cameras are dirty. A number of cameras annoyingly don't actually indicate what ISO is selected when DX coding is used.

As another poster suggested, are you certain that the film was bulk loaded correctly with the emulsion facing the lens/shutter?

This must be some kind of user error or user equipment failure. A bulk roll doesn't suddenly lose 2-3 stops.

 

[Donald Qualls]

By any chance were the speed-loosing rolls spooled such that the base faces the lens when loaded into the camera, as one would do for redscaling of colour films?

This is a possibility, though I'd expect to lose more than three stops in this case. The one time I've done this (misloading film in a plate camera's film sheath) the loss was four to five stops.

 

[pentaxuser]

I did with a roll of Foma 200, it came out fine.

It all sounds as if the 400 crossed lanes while it was being wound and joined the 200 lane. Cars do this on motorways without warning and problems result

Íf you are looking for a "proper " analysis I cannot give one. Based on everything you said either something has happened to the 400 when it was being wound at the factory or you have overlooked something in your process that went wrong

I have a feeling that you may be the only one apart from Foma who can find out the problem

pentaxuser

 

[koraks]

It all sounds as if the 400 crossed lanes while it was being wound and joined the 200 lane.

Not really as those two are quite nearly the same speed...

 

[Raghu Kuvempunagar]

This is a possibility, though I'd expect to lose more than three stops in this case. The one time I've done this (misloading film in a plate camera's film sheath) the loss was four to five stops.

Isn't Foma films notorious for their not so effective AH layer?

 

[Donald Qualls]

Isn't Foma films notorious for their not so effective AH layer?

I haven't noticed problems with this, but I use Foma almost exclusively, so I might have forgotten what a good AHU looks like...

 

[Paul Howell]

Ive used bulk film on and off for going on 60 years, this is a first for me. 3 rolls, 3 cameras, 3 developers, don't know how it could be user error. Today I started a test roll, shot at 50, 100, 200 and 400 with enough frames left for shooting my test chart at 50, 100, 200 and 400. The rolls that were under exposed all had highlights just no shadow detail.

 

[pentaxuser]

Not really as those two are quite nearly the same speed...

Yes I admit to there being a certain whimsy and jocularity to my comment. It was mshchem mentioning Foma spooling the wrong film that led to me having a picture in my mind of that cartoon of two lines of rushing traffic where the mischievous, not to say suicidal little car wants to cross lanes so it performs a form of self compression where its back arches and that enables it to spring into the next lane unharmed. It always amused me

It's a variation on the Tom and Jerry cartoons where Tom the cat charges at Jerry the mouse who picks an anvil at the last moment. Jerry runs into the anvil and then walks away assuming the shape of said anvil for a few moments

A form of surrealist humour I suppose

pentaxuser

 

[pentaxuser]

Ive used bulk film on and off for going on 60 years, this is a first for me. 3 rolls, 3 cameras, 3 developers, don't know how it could be user error. Today I started a test roll, shot at 50, 100, 200 and 400 with enough frames left for shooting my test chart at 50, 100, 200 and 400. The rolls that were under exposed all had highlights just no shadow detail.

Paul,looks like we can either blame Foma or think very carefully before making with any more suggestions in reply

I was out of ideas after reading your opening post and I am even more out of them now

pentaxuser

 

[Donald Qualls]

The rolls that were under exposed all had highlights just no shadow detail.

That's typical of underexposure -- and exactly what we'd expect if the film had been wound backward on the cassette spool.

Can you check any of the frames for reversed image? When viewed from the base side, you should see the same orientation as the original scene...

It just occurred to me that there might have been a botched splice in the roll -- changing it from emulsion in (standard for still film) to emulsion out (used in some cine applications -- and Foma confections both sorts).