Paper Fogging

[PhotoTyler]

I know this is a simple question, but i'm curious what causes fogging on paper. I was wondering if maybe the dark light was too bright, but i turned it down and it was still there. I stopped the enlarger lens down to around F8 or F11 and it seemed to reduce it a little bit, do you think that stopping the lens down would reduce fogging on the pirints?

If you need any more information to try and figure this out let me know. Thanks a lot for your help, i've only been into the darkroom for a couple years, and i really want to start getting some good prints, and you guys are always really helpful.

 

[eric]

Take one out, put it on your easel, leave it for about 30 seconds, then develop it. Is it fogged? If so, it could be your safelight. Take another one out and turn off the safelights and develop it. Is it fogged? Could be the whole box. Is there light coming out the side of your enlarger? (near the bulb?). How far is the safelight from your paper?
Try putting some sheets of paper inside the safelight to tone down the light a little bit. Where is the fogging actually? The whole paper? Or on the edges?

 

[lee]

Lots of things can cause fogging. A safe light that is not safe... older paper not stored in a cool dry place...light leaks from the enlarger...light leaks from holes in the walls of the darkroom...paper left out and struck by light or a hole in the box or wrapper. We are gonna need more info before we can help too much.

lee\c

 

[Paul Howell]

Turn out the safelight and develop an unexposed sheet of paper for your normal time, then fix it and see if the fog is still there, if the answer is yes then look for a light leak, or your box is fogged. If not check to see if you have any light reflected from you enlarger back to the paper, or if your developer is too strong, or your developing time is too long.

 

[PhotoTyler]

thanks for the quick responses. according to what you said it seems like it is probably my safe light being too strong but i'll test it out tommorow.

Thanks a lot.

 

[lee]

when testing safe lights you should probably make a test print with the safe lights off and no neg in the enlarger. develop that and see where the tone first shows up. then make another print at the time just short of where the tone is. then lay keys or coins on the paper for a time like 1 min and process the paper. If no tonality shows then make another exposure and leave out for 2 min and then keep doing this until you are at about 5 min. Paper safe lights should be in good working condition and safe for at least 5 min. If it turns out not save change the bulb to one of a lower wattage like in the 20-30 wattage area or attempt to move the save light futher away from the paper.

lee\c

 

[nworth]

There are three possibilities: light, age, and chemicals.

For light, turn off the safelight and let your eyes adapt to the dark (at least 5 minutes). If you see any leaks, fix them. Then develop an unexposed sheet of the suspect paper in total darkness. If there is no fog, look for other sources of light leaks, like excessive spill from the enlarger, pilot lights and LEDs that are too bright (especially if they are blue), or a faulty safelight. Do the safelight check first. Some inexpensive safelights deteriorate with age. Having the safelight too close of too bright could also be a problem.

Sometimes chemical fumes get to the paper and fog it. Usually this kind of fog is worst at the edges. I got a brand new (supposedly) batch of Multigrade a while back that had this problem. Fogging can also be caused by chemical contamination, especially of the developer. Be careful to wash all the containers completely, and mix the chemicals carefully. In some cases, purified water (distilled or deionized) may be needed.

Papers all lose contrast and gain fog with age, especially when stored casually. This usually takes years before it's noticeable, although real abuse (like high temperatures and high humidity) can cause it to happen sooner. Paper keeps a very long time when well sealed and kept near freezing. Minor age fogging can be compensated for by additional bromide or benztriazole.

 

[Ronald Moravec]

The proper way to test a safe light is to presensitise a piece of paper and let it then be exposed to the safelight for double the normal exposure time.

to [presensittise, you make successive exposure steps under the enlarger. The last step with the most exposure before it goes starts to go grey is the exposure you want.

Then you preexpose a whole sheet to that level, add some light blocking material like coins or easel blades, and let it twice the time it normally would be exposed to the safelight. You should not see any patterns or the light is not safe enough.

The idea is not to grey delicate highlight values when making a print. Subtle fog will show up here first and you probably can not detect it.

 

[photobackpacker]

If your paper and chemicals are fresh, there are really only three possible sources of fogging:

1. Light leaks in the darkroom admitting unsafe light from outside light sources.
2. Safe lights that aren't. To test these follow this link:http://www.kodak.com/global/en/consumer/products/techInfo/k4/k4TestSafelite.shtml
3. Non-image light from your enlarger. These come in two flavors:
a. Reflected light off the easel and paper being bounced back onto the surface of the printing paper - unusual unless you are in a jury-rigged darkroom in your bathroom with mirrors to help out..... OR
b. Light leaks from your enlarger. These can be intense enough to do the job on their own - even with the best of enlargers. Put a lens cap on your enlarging lense, turn off all lights and sit in the dark for 10 minutes. When your eyes are totally dark adapted, turn your enlarger lamp on. You may be in for an enlightening experience. :0

Good luck