35mm film development density line error

[Tom Kershaw]

Although I've not developed a huge amount of 35mm film recently, as I'm predominantly a medium format user, I haven't come across the following film development fault before:

This line continues for approximately two strips (12 exposures) and then starts to fade away. I've not yet printed the negatives, but I suspect this line will be visible. A possible light leak through the felt entrance of the canister?...

Film: ILFORD Delta 400 (June 2007 use by date)
Developed in Pyrocat-HD 1+1+100, 10 minutes @ 26ºC with a Jobo ATL-2300.

The film batch code is: '96BTH1C01/03'

Tom.

 

[Ian Grant]

I've only seen this once, back in the 70's with FP4 and it was caused by dirt in the light trap, it will print, I think it causes stress to the emulsion, it's not a light leak. The dirt eventually dislodges and the line stops.

Ian

 

[Nicholas Lindan]

I would guess a manufacturing defect in the film.

 

[Tom Kershaw]

I would guess a manufacturing defect in the film.

Could you elaborate?

Tom.

 

[kozesluk]

looks like it is not a line in the emulsion but a line on the film surface actually.

are you sure it is not a water scale mark or any wetting agent residue? I've got something simillar recently and it was caused by a hard water wash...

 

[Tom Kershaw]

looks like it is not a line in the emulsion but a line on the film surface actually.

are you sure it is not a water scale mark or any wetting agent residue? I've got something simillar recently and it was caused by a hard water wash...

Lukas,

No, it is not a physical deposit.



Tom.

 

[gainer]

Anything that causes pressure on the film will cause the points of pressure to develop just as if light-struck. This effect was used in bygone days in the Kodak Autographic cameras. A bit of grit between film and pressure plate will cause such pressure marks. A nick in the plate will also, but one would expect that to be continuous.

 

[Ian Grant]

Anything that causes pressure on the film will cause the points of pressure to develop just as if light-struck. A bit of grit between film and pressure plate will cause such pressure marks. A nick in the plate will also, but one would expect that to be continuous.

I had lines on a roll of Fomapan 200 a few weeks ago on that occasion it was a manufacturing fault, but thes lines are exactly waht you get from grit.

This effect was used in bygone days in the Kodak Autographic cameras.

Actually that's not correct, I assumed that too in a post a few weeks ago and someone posted a link which showed clearly that the camera's needed the dedicated Autographic film with it's unique backing paper. I think may still be a weak stress related image from the stylus with conventional film.

Ian

 

[Kirk Keyes]

Autographic - I'd never heard of them. Eastman/Kodak paid $300,000 (1914 dollars at that) for the system according to the wiki page. I bet Kodak lost a bit of money over that deal...

 

[Ian Grant]

Autographic - I'd never heard of them. Eastman/Kodak paid $300,000 (1914 dollars at that) for the system according to the wiki page. I bet Kodak lost a bit of money over that deal...

Don't be so sure Kirk, the Autographics were sold world-wide, remember that in the UK Camera Bellows, in Birmingham mad over a million sets of bellows for Kodak consumer cameras. Kodak made cameras in the US, Canada, the UK & Germany pre WWII, they also had a factory in Australia but I don't know what that made.

So when you realise the sheer volume of Kodak cameras and the associated films $300,000 pales into insignificance. I have a very nice Autographic camera, and it would appear looking at some of my fathers pre-WWII photographs he used one at some stage.

Ian

 

[Mark Layne]

I've only seen this once, back in the 70's with FP4 and it was caused by dirt in the light trap, it will print, I think it causes stress to the emulsion, it's not a light leak. The dirt eventually dislodges and the line stops.

Ian

Oddly enough I bought several bricks of Orwopan from J&C a few years ago.
One brick had this line on many of the rolls in almost the same location. The scratch was easily seen on the leader and must have occured before the cassettes were loaded from the master roll.
If the image is important painting the entire surface with Edwal No Scratch might help

Mark

 

[Ian Grant]

No scratch remover can remove the OP's scratch as it's stressed emulsion, but sure scratches on the film-base can be lessened or hiddened with care.

Ian

 

[Tom Kershaw]

Tomorrow I may try and get the camera very clean inside (Olympus OM-2n), and run another roll of Delta 400 through the camera from the same batch, checking for grit in the light trap.

Tom.

 

[gainer]

Actually, any paper backing should have done for the common film of the day which could be developed under red light. There is a window in the back, as Ian knows, that can be opened so that a message can be written by pressure from a furnished stylus through the backing paper.

The OP's problem could also be from grit in the cartridge lip.

 

[Nicholas Lindan]

If the dark streak was caused by grit I would expect there would be a scratch or indentation along the streak.

I take it the streak is developed silver in the emulsion, and does not reside in the base or anti-halation backing. Sometimes dye particles used to color plastics don't dissolve completely and leave trails as the plastic is extruded.

 

[Tom Kershaw]

If the dark streak was caused by grit I would expect there would be a scratch or indentation along the streak.

I take it the streak is developed silver in the emulsion, and does not reside in the base or anti-halation backing. Sometimes dye particles used to color plastics don't dissolve completely and leave trails as the plastic is extruded.

Nicholas,

The doesn't appear to be a scratch or indentation. On closer inspection, the strip looks like an area of significantly reduced density, or less emulsion.

Tom.

 

[Nicholas Lindan]

On closer inspection, the strip looks like an area of significantly reduced density, or less emulsion.

It might have been caused by a bit of crud getting caught in the coating blade when the emulsion was being applied.

 

[Tom Kershaw]

It might have been caused by a bit of crud getting caught in the coating blade when the emulsion was being applied.

Wouldn't the film be checked for this type of defect during manufacture?

Tom.

 

[Ian Grant]

It might have been caused by a bit of crud getting caught in the coating blade when the emulsion was being applied.

Ilford use cascade coating so that's not possible.

Stress marks don't always have a corresponding physical scratch.

Ian

 

[Tom Kershaw]

I experienced this "fault" again with a roll of 2014 expiry dated FP4 Plus 135/36 a few days ago using a different camera (Nikon F100). The line was visible on the film leader before loading into the camera.

 

[Tom Kershaw]

Two rolls of Delta 100 processed on Saturday also show these apparent stress marks, both in Paterson Super System 4 tanks, one roll in FX-37 1+3, and the other Pyrocat-HD 1+1+100. Interestingly one of these rolls also shows a wave pattern of similar type in the film designation area. Perhaps double checking for grit in the film take-up spool mechanism is in order.

Tom