Thin, sharp BLACK LINES....(Negatives) : LUSENET : Large format photography : One Thread

I am getting thin, sharp black lines and also, somewhat wider, "out of focus" grey lines through some of my my B&W negatives. What causes this and how can one avoid it?

FYI: I tray develop my Ilford 4x5 sheet film. Does the above described problem sound familiar to anyone else? Please help. Andre

PS For what it's worth, I see the occaisional white scrath line, and the cause for this is obvious: one sheet film scratched another in the trays. And also, I sometimes see very similar defects in my B&W prints.

Possible causes: static electricity?, emulsion cracking due to differing temperatures? (admitedly, my final washes for negs and prints are not at same temp as the chemistries preceeding- gotta correct that), scratching emulsion prior to exposure/processing?, or something else?

Thanks again for your help.

-- Andre Noble (, July 26, 2001


Andre, Is this a regular problem? I suffered the same type a while back on a whole box of FP4+. I reckon it was a production fault. The lines ran straight across each sheet in the same place. I may be wrong but I would have thought that static would produce a very irregular pattern, same goes for emulsion cracking (although I have never heard of this sort of problem - IMHO you would suffer reticulation long before the emulsion cracked). As for scratching prior to exposure - the only thing to do is to give the film holders a real good clean. Hope some of this helps!! regards paul

-- paul owen (, July 26, 2001.

Paul, the lines are irregularly oriented, not necessarily horizontal across the film. I'm satisfied that the thin lines which appear clear to naked eye but "black" upon inspection with a loupe, very well may be due to scratching with another sheet film.

But the out of focus, oddly shaped wider grey marks appx 0.5 to 1.0 cm and 0.5 to 1.0mm wide remain a real mystery. I may just bring these negs to my local photo colege and have my ex-teachers troubleshoot them. I'll report back. Andre

-- Andre Noble (, July 26, 2001.

I have experienced the same problem once, on 3 sheets of film shot on the same day, same location. The marks on the film look like small lighting bolts and they are slightly out of focus. I loaded all the film in the field with a Harrison Changing Tent, and they were all processed at the same time. I figured they were processing flaws, but now that you mention static electicity, I think it could be, Only happened once, but I'll pull the dark slide slowly now so as not to generate static. Dave

-- Dave (, July 26, 2001.

Yes Dave. Static electricity due to pulling the darkslide too quickly. That makes sense. I was thinking originally that those out of focus densities (streaks) were caused by emulsion contact with the dimpled bottom of the new chemical trays I processed the sheets in. But in that case, I imagine the small streak would appear as a sharp density, and not the "out of focus" type.

Incidently, I recall the day I yanked the plastic dark slide on present negs was rather arid too.

Here's a follow-up question for anyone: I wonder if one also has to be slow about PUSHING in the darkslide too? Or how about post- exposure when the exposed sheets may slide past one another during transport as they lay in their triple boxed containers? ie, s this a source of static eletricity too? Or is it mainly be careful with the dark slide? Andre

-- Andre Noble (, July 26, 2001.

I don't know the cause of the problem but I think you can eliminate the divergence in processing chemical temperature as the cause. Very large differences from developer to stop and fix can cause reticulation but a negative that suffers from reticulation doesn't look anything like what you're describing. Also, I think the difference in temperature must be really extreme before reticulation occurs. I regularly develop film at 68 degrees and my stop and fix temperatures are usually in the low 80s. I've never had a reticulation problem with those kind of temperature differences.

-- Brian Ellis (, July 26, 2001.

Brian, thanks - that's reassuring info to know. Andre

-- Andre Noble (, July 26, 2001.

just an additional thought, but I've just read a letter in a photo mag from a reader who suffered similar marks on 35mm film. He eliminated most possible causes but the one thing he hadn't reckoned with was safelight fog. The reply to his letter suggested that this was a possible cause of the strange marks. Could they be as a result of safelight fogging and the ribs in the base of the dev tray?? As I said, just a thought!! Regards Paul

-- paul owen (, July 28, 2001.

I would venture to say that the grey lines are the result of, not scratches, but depressions where you ran the emulsion side up against something that didn't cause a scratch but merely a depressed area of the emulsion. Like running a smooth but narrow object along the emulsion. Press you fingernail into the soft emulsion, not enough to pierce the emulsion, but enough to dent it. You'll see the same type mark on the print you see now as a line.

-- james (, July 29, 2001.

James, it's possibly caused what by what you are talking about. I'm still perfecting this tray development, and during this batch, made the error of letting the sheet films slide over each other in the presoak, stop, and fix - definitely causing the scratches, and possibly causing the darker, mysterieous marks, as you suggest. FWIW, I was using dimple bottom trays and emulsion down during processing. My first thought was it could be caused by dimples/emulsion contact of the sort you mentioned. Are these trays o.k. to use w/film/paper emulsion side down?

Well today, Sunday, Freestyle here in Los Angeles was having this incredible blow out tent sale, and I spent the rent on a brand new Jobo CPP2 processor and new lift at a total cost of $391.00 cash (not a misprint) including the tax! I don't know if this was just an impulse purchase I will regret, but I've been looking at these for 5 years now. There is already alot that can go wrong when doing B&W, and I'll take advantage of the Jobo, to minimize negative problems. Thanks again all for the help. Andre

-- Andre Noble (, July 29, 2001.

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