C-41 disaster

hka · Apr 16, 2007

Saterday after a nice photo-day I came back home and went directly into the darkroom. I shoot that day several b&w and some color negatives on 9x12cm format.
Developing the b&w causes no problem but after developing the sheets in C-41 I was realy surprised to see what came out. I saw 3 completely blanc sheets with some little vague contours. Further no imprint and no orange mask. The fourth sheet, all developed in the same run, was perfect and OK. Most surprising for me is that there is no orange mask. Normaly if you forget to remove the slider from the filmholder there will always be an orange masks and imprint left. The sheetfilm I am using was KODAK type Portra 160NC PRO. Still to mention is that sheet 4 was from an other box and emulsionnumber. Have anybody seen this before and what can it be??

AgX · Apr 16, 2007

The missing of a mask could be
-) a manufacturers fault
-) a processing fault
but no handling fault.

As all Portra sheets were processed once, and as the only flawless sheet came out of a different box from a different batch one can deduce that it’s a production fault. So far logics.

But kowing how film is produced and controlled (at Kodak) I am as puzzled as you. Thus back to handling your sheets… I’ve got no idea.

Photo Engineer · Apr 16, 2007

The lack of an orange mask can never be a processing fault. That orange mask is an integral part of the film and nothing can remove it short of a soak in a strong organic solvent.

You may not be able to see it if the film is not bleached and fixed. In that case the film would be a gray sheet, rather opaque?

I take it that the film was clear though. If you get clear film through a C41 process, it is probably B&W film, as that will be the result. The emulsion will eiither be removed at 100F or the silver image will be bleached out just about totally. I think it was B&W film if it was clear or nearly clear.

PE

AgX · Apr 16, 2007

PE,
if there was no chromogenic development at all, there would be no mask. That's what I meant.
(Otherwise,... was just lying a bit in the sun, might be off track meanwhile...)

bye

Photo Engineer · Apr 16, 2007

If there was no chromogenic development, there would be a mask. That is my point. The mask is put in at the factory. It forms a positive image during negative development.

The orange uniform color would be there, but if the film is blank and clear or had a weak image, then it was not color negative film, it was B&W or it was totally defective.

A B&W film run through the C41 process would have either a weak negative image or none at all depending on whether the emulsion withstood the 100F process, as stated above, otherwise a color negative film would always have an orange color from the mask regardless of processing conditions.

PE

hka · Apr 16, 2007

Stupid me ! ! !
PE has right it's b&w film. I looked at the notches and it's clearly b&w. I was so disappointed about the results that I overlooked this.
How it came??
Well, during an earlier shooting I changed from filmtype and put (in this case) the b&w sheets in an empty Portra box and forgot it. Saterdaymorning I reload the holders with that film and a new one from a new package.

I thanks you very much for the answers.
Sorry also to Kodak...

Conclusion: I have learned a lot this weekend...

Photo Engineer · Apr 16, 2007

Harry;

Thats why I always check notch codes before processing.

I learned just the way you did, the hard way. Only at Kodak, wasting time was not appreciated by the boss let alone your own displeasure with yourself.

PE

hka · Apr 17, 2007

In my case I would say it's maybe better to check the notch codes before loading the filmholders .

radiantdarkroom · Apr 17, 2007

I used to work at a photo lab where we processed B&W E6 and C41. It was some hilarious when somebody would send 4x5 to the lab for processing and would not write down what process the film was and/or mix different ones together. So this all came down how competent I was and if the lab had all the notch codes for every kind of film that was out there.

C-41 disaster

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