film fogging

[Steelbar]

film fogging-could it be from darkroom chemicals

I have been doing an exposure test and realized I was getting film fog. I assumed it was light leaks. To make a long story short I completely sealed up all light leaks and worked at night. I did a test with Ilford HP5 plus 4x5. I exposed the film just enough to get over the threshold and than placed the film on the counter in complete darkness. I put coins on the film and removed them one at a time every three minutes, than processed the film. I also moved my timer and covered it so that it would not fog the film. I do not have flourescent lights. At that point it was the darkest darkroom I have ever worked in. The result was that the coin that was not removed was clear but I could clearly see the image from the other coins. I have used this darkroom for many years for alt photography. could it be a chemical fog from chemicals in the air? Has any one experienced this?

 

[trythis]

I can't help, but your question is very interesting. The thread might get more audience with a title that gives more detail. I was expecting a thread about old expired film that has fogged from age. How about "film fogging in dark room fumes?" or something.

 

[snapguy]

If there were than many nasty chemicals in the air I would think you'd have keeled over years ago. Are you using new film? Does the film get to you by dog sled and suffers from thawing and freezing on the trip? Are the Russians bombarding Canada with microwaves like they did San Francisco years ago? Is your darkroom radioactive? I assume you put the coins and film under glass. Are there chemicals on the glass?

 

[Steelbar]

Snapguy when I saw that it was fogged I did think that my health or my sanity could be at risk. The film is fresh and not frozen. The film was not under glass, it could be the Russians. I am grasping at straws to figure this out. I may try the test again at another location in my darkroom. Thanks

 

[MattKing]

Steelbar and I were talking about this at our last Darkroom Group event.

Is there any chance that there could be some stray exposure from your UV exposure source?

 

[Steelbar]

No chance Matt. It is in another room and I did check it and it isn't plugged in. I also checked that none of the bulbs in my darkroom were florecient. If you think of anything else let me know. Something is causing it but it's sure not obvious to me.


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[Bill Burk]

I've seen LED bulbs glow. And I've heard about cellphones in pockets glowing.

Only thing I can recommend is spending a half hour in the dark and with a stepstool... Move your head up-down and around.

I use curtains on rails to darken my darkroom inside an otherwise "open" garage, which I make as dark as possible.

I've found light leaks under my sink where the curtains meet the ground (and had been pulled away). I've seen curtains leak from the perspective of the film, which are completely black from my usual point of view.

 

[MattKing]

Try a test with a piece of 35mm film or 120. Send me an email if you need some bulk loaded TMAX 400.

 

[Ken Nadvornick]

I believe that the presence of sulfide (brown) toners can in some cases fog light sensitive materials? Long ago when I worked as a printer in a professional darkroom I kept that stuff outside until needed, just to be safe.

Since you have worked with alt processes, any chance that something along those lines, or similar, might be contributing?

Ken

 

[BetterSense]

I bulk load 35mm HP5 in my lab and by the time I get through a dozen rolls, I can see the outline of my hands against the wall. It seemed pitch black in there even after a couple minutes of adjustment, and I have never seen a fogging problem, so I just keep doing it.

I do not fully understand the coin test. Can you explain again?

 

[RattyMouse]

I believe that the presence of sulfide (brown) toners can in some cases fog light sensitive materials? Long ago when I worked as a printer in a professional darkroom I kept that stuff outside until needed, just to be safe.

Since you have worked with alt processes, any chance that something along those lines, or similar, might be contributing?

Ken

Just a few ppm of sulfides in the air is all it takes to set off your nose, so I dont think there can be such chemicals floating through the air undetected.

 

[RattyMouse]

I bulk load 35mm HP5 in my lab and by the time I get through a dozen rolls, I can see the outline of my hands against the wall. It seemed pitch black in there even after a couple minutes of adjustment, and I have never seen a fogging problem, so I just keep doing it.

I do not fully understand the coin test. Can you explain again?

The coin is shielding the part of the film that it rests on. He has multiple coins on the film and removes them in a series of different times, in effect changing the exposure to the film.

 

[Bill Burk]

The thought occurred to me that this test for fog, devastating in a print... reveals a very slight density change in the shadows of a negative.

If it is a light leak, it might not be as devastating a light leak as it seems. Although all fog is undesirable, in practice when you print a negative, you can print through fog. Although you can see the density difference, it might not even be significant (might be less than 0.01 density difference).

 

[MattKing]

I think it is because of all the years that Steelbar worked around dentists.

He probably glows in the dark

(do you have a luminous face on your watch?)

 

[MartinP]

If you develop and fix a piece of the bulk film directly from the bulk roll, does it have a comparable fog level? If it is clean, then proceed to debugging the loading of the bulk roll in to cassettes - does that have a similar fog level and, if so, what were the circumstances of the loading?

For the eye to be fully dark accustomed can take up to forty minutes and by then, with a healthy eye, it can supposedly detect single photons of light (according to a text book on a course I did about thirty years ago), so sitting in the darkened darkroom for over thirty minutes before moving your eyes around at every level and angle should provide a definite answer to the light leak question at least.

 

[1920]

I have been working on setting up my darkroom this week- it seems the 'night vision' time seems to vary widely with individuals. Our experience indicates that age could be a factor? We set up in there last night, and my (much younger) friend was seeing her hands within a few minutes. It took over 20 minutes for me to catch up- I don't think I reach full sensitivity until about 30 minutes….which absolutely feels like ETERNITY sitting in the dark! But man, when you finally get there, its amazing all the tiny, tiny light leaks there are.

I guess the point I'm trying to make is- the darkroom probably ain't dark man….I think this business about chemical fumes seems unlikely to me…

Just my 2C based on recent experience…..

….actually, someone already kind of touched on this, but what level of darkness is acceptable from a practical point of view? Should we be continuing to chase these smaller and smaller leaks or is a level of light like the OP is experiencing (barely visible fog on pre-flashed ISO 400 film after several minutes, correct?)…is that basically "OK" to work around?

Do most of you guys have true 100% blackness, esp. in improvised/temp darkrooms?

 

[Steelbar]

When I do the coin test the last coin is not removed till just before I put the sheet film in the developer. That last spot is clear so the material is fine and not fogged. We except for the pre fog I do in the camera. Waiting in the dark for 30 minutes is how I found the original holes and plugged them. Now I can't see any beams of light. So more and more it looks like it is a chemical problem and I will have to clear out all chemistry and wipe the place down. I have been in some pretty discussing dark rooms and I don't think mine is that bad but it is possible that one of the alt processes I've used has contaminated the room. I hate to think about what may have done to my lungs!
Matt, maybe it's a build up of mercury from all those fillings I photographed.


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[Steelbar]

1920 I think generally those light leaks should not be a problem as the time the film is actually exposed in the darkroom is short. The film I did tonight just went from the film holder to a film rack and into the tank, that's probably less than two minutes. If I was using an 125 ISO film it would even be less of a problem.


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[1920]

Good point- for roll film its a short time. Unfortunately, I am also going go be doing tray shuffle developing of 4x5 sheets so I really need to get this sucker light tight as possible. That coin test idea is smart- I'm going to try that tomorrow.

Nighttime/daytime is a big difference for my setup.

I just can't wrap my head around this idea that chemicals in the air could be fogging your film, but I suppose anything is possible. maybe repeat the test after your cleaning?

 

[mauro35]

Hi APUGuser19,

I believe you are not the only one seeing patterns when you close your eyes. The eyes are sensitive to mechanical stimuli as well. But the only information they can give to the brain is visual, therefore patterns appear and you have the impression to "see" them. If you squeeze your eyes hard when you close them, you´ll see even more spots or patterns. This article could be also interesting for you to understand just how complex is the relation between our senses and the higher brain:

http://www.sciencedaily.com/releases/2013/10/131031090431.htm

 

[Xmas]

Your dark room is leaking.

The acid test is to repeat the test with clear plastic replacing the coins.

The dark room has to be you cannot see anything after 60 minutes, (if you are a teenager after 15).

If you can see anything you should be able to see the culprit.

Noel

 

[Steelbar]

Mauro-That was a great article and I came to the same conclusion but didn't really understand it. I did the hand waving and could see my hand than closed my eyes and could still seem to see my hand. There were times I thought I could see things in my darkroom but that was really only that I knew they were there. If I spun around and lost my sense of direction I could not see those objects. It's amazing what you can learn when you stand around in the dark with nothing to do. [emoji4]


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[Steelbar]

Noel- I don't think it was the coins as the area were the coins were not was fogged. I did consider that the metal of the coins could be effecting the film. When you have looked at all reasonable explanation you start looking at the unreasonable.
I just thought of another way to look for a light leak. If I set my camera up with a wide angle lens in my darkroom and leave it exposing for a very long time I may find there is a leak. I really can't see there is a light leak with my naked eye.


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[mauro35]

Mauro-That was a great article and I came to the same conclusion but didn't really understand it. I did the hand waving and could see my hand than closed my eyes and could still seem to see my hand. There were times I thought I could see things in my darkroom but that was really only that I knew they were there. If I spun around and lost my sense of direction I could not see those objects. It's amazing what you can learn when you stand around in the dark with nothing to do.

Exactly, the expectation is sometimes a fundamental component in our perceptions, our brain can trigger responses because we expect to have them and that explains for instance why we can sometimes even believe we heard the phone ringing if we were expecting an important call.

Hope you find a solution for the fogging

 

[Gerald C Koch]

I seriously doubt that any chemical fogging would result in shadows of the coins as indicated in your test. With chemical fog you would get an overall fogging.