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FP4+ banding

paul_c5x4

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Location
Ye Olde England
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Processed two sheets of FP4+ in a Paterson Orbital - The sheets placed in diagonally opposite corners. Running on a motorised base for constant agitation, I used the following steps & chemicals:

5 minutes presoak - 200ml
16 minutes in Perceptol 1+3 - 240ml
30 sec water stop - 200ml
8 minutes fix - FX40 at 1+7 - 200ml

One sheet came out evenly developed, the second had a thin strip that looked as if it hadn't cleared properly. Dunked it in a tray of fresh fixer for five minutes before washing & drying.

Dead Link Removed
Notches at hinge end of the DDS.

Dead Link Removed
Line shows where the band occurred in relation to location of film in the tray.

Can rule out camera fault - Did two shots on the same setup and the second neg came out OK. Used the same development process with other sheets...

Has anyone experienced this before ?
 
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Only had that when two sheets touch in a Jobo tank, some things done similar to your sheet here preventing developer reaching that part.

Maybe the other sheet rode over on top during processing, right at the start of development too.

Ian
 
Ian Grant said:
Maybe the other sheet rode over on top during processing, right at the start of development too.
Click to expand...

Edited original post and included a shot of the tray/film indicating where the banding occurred - This rules out films overlapping and the line is too sharp to be uneven development.
 
If it's not developer related it must be occurring during exposure, it's unlikely to be a coating fault, Ilford's QC is extremely good.

Ian
 
Something intruding into the frame during exposure would have left a fuzzy line unless it was in contact with the film. If you look closely at the (scanned) neg, one side of the defect has a sharply defined straight edge, and the other side fades out towards the outer edge.

I think development issues can be ruled out due to orientation in the tray and the second sheet came out OK. As already mentioned, there was a thin strip that needed another five minutes in the fixer to clear - This makes me suspect a coating defect, even with a rigorous QC, faults slip through.
 

If it was acoating defect in this case there would be no emulsion, so you wouldn't have had a problem with that line needing extra fixing.

If however something was in contact with the film along that line during development & fixing then first it would cause that hard line, and the softer edge behind and the issue of the area needing additional fixing would make total sense.

A coating fault would be either too little or no emulsion, ruled out because the area didn't fix initially, or too thick an area of emulsion, in which case it would still develop, so it's not that.

So it sounds far more like a problem during processing now you've told us about the fixer problem. Perhaps something was sticking to the tank lid.

Ian
 
I'd guess either not enough liquid or not enough tilt to the tray or the film wasn't flat against the bottom. Possibly all three. Most hard-to-solve problems are a combination of multiple causes - and checking only one cause at a time won't reveal the problem..
 

Not enough liquid or tilt produces entirely different problems. This wouldn't account for the clear line.

Ian
 
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I think Nicholas is on the right track, something caused that sheet to lift out of the developer just enough, maybe due to tilt or not enough fluid. Sometimes film will curl if part of it is wet and part is dry. This might have happened for only a portion of the entire time. The clear line comes from fixing an undeveloped area on the film.
 
Sent the offending sheet to Ilford for their expert opinion..

I have to say that it is not looking like anything I am recognising from my years working in coating, or Tech Service evaluating products/handling complaints. I showed it to other colleagues in other departments, but they too are scratching heads as to a possible cause.

The opinion at Ilford is leaning towards a developing fault, however, a manufacturing defect has not been ruled out entirely.
 
Perhaps you could tell us a little more about the image. To me it doesn't look like either a negative or a positive. Obviously since the border is transparent it is a direct scan of the negative but it looks like it must have been preflashed or something. I just wondering if something further up the chain could be involved.

Denis K
 
The image is a straight scan of the neg using default settings on an Epson V500 flat bed. No adjustments were made of black/white points, nor any dust removal or sharpening algorithms applied. The shot it's self is of the interior of Norwich Cathedral using a 15 second exposure at something like f22 (as I recall). A duplicate exposure was made on the other side of the DDS which came out just fine using the same development regime...
 
paul_c5x4 said:
The image is a straight scan of the neg using default settings on an Epson V500 flat bed.
Click to expand...

I guess it's just a strange subject. I flipped you image and looked at it as a positive and it looked more like a negative than the negative did.

Denis K
 
Trying to construct an event that could cause this - here's a wild one - is it possible that the exposure time was long - at least several seconds (looks like a large interior), and the dark slide was re-inserted, part way before the exposure was finished?
 

This wouldn't explain the narrow strip of exposed film on the top of the image. Furthermore, this looks like the end of the film farthest from the dark slide.

It seems almost impossible to me that this problem was produced in the camera. Either the film was damaged before it went into the camera or after it came out is my guess.

Denis K
 
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