Troubleshooting: Darkening of prints.

Jos De · Jun 4, 2008

Hey everyone,

I'm having a frustrating problem in the darkroom. I'm printing my images great and the process is as smooth as it could be but after I wash and dry; when I bring prints upstairs and place them in sun light they begin to turn noticeably darker. Now I thought it was my fix but I stirred up a new batch. This leads me to guess that either my developer is exhausted (it is rather old) or my batch of paper is weak. It was given to me by a friend unopened so I don't know. It's just frustrating printing what are very acceptable prints (mostly for bromoil) and then checking on them the next day and they have darkened incredibly and lost tremendous amount of the contrast (there are no any more whites, just grays and blacks). Does anybody have any ideas or experienced this before?

Thanks for any insight!

Joe

RobC · Jun 4, 2008

which paper? which developer, which fixer?

Les McLean · Jun 4, 2008

If you are using fibre paper you are seeing the effect of "Dry Down" which happens because the fibre paper base contracts as it drys causing the print to get darker. This is quite simply rectified by taking the dry down factor of the paper into account and reduce the exposure before you make the final print. I have an article on my website that will help you understand dry down. I have also written a description of how to calculate dry down for all fibre papers for they do differ.

Follow this link http://www.lesmcleanphotography.com/articles.php?page=full&article=28

synj00 · Jun 4, 2008

Les, that article is outstanding. Thanks!

Jos De · Jun 4, 2008

Rob, I'm using ilford multi-grade IV resin coated, developing in dektol and fixing with regular kodak fixer.

David Brown · Jun 4, 2008

Jos De said:
Rob, I'm using ilford multi-grade IV resin coated, developing in dektol and fixing with regular kodak fixer.

Dry-down is not your problem with RC paper. You said the prints turned darker with no whites. That sounds like the paper could be fogged, but you would likely see that in the developer, not later. If they turn "dark" after fixing and only when exposed to light, then they are not fixed properly. You do not mention a stop bath. Even water will help, but I suspect that the fixer is not enough. Also, are you diluting the Dektol? Read the directions on all chemicals and the paper, and see if something isn't right.

RobC · Jun 4, 2008

Well dry down is always a factor and can easily lose your midtone/highlight punch in the print. But what you seem to be describing is extreme contrast shift which I have never seen happening from dry down, especially after the print has dried.

I would make sure you develop to completion. That is, better to use less exposure and more development rather than more exposure and less development. Probably 90 seconds to 2 minutes + for that paper, especially if it is old stuff.
And make sure fix is at correct dilution and don't curtail the fix.

Photo Engineer · Jun 4, 2008

Sounds as if the paper is not properly fixed and is printing out silver metal in sunlight. This is true if there is any retained silver halide.

The effect Les mentions is also due to the amount of coated gelatin, and therefore can be seen on RC papers of differing thicknesses or on RC and FB papers with different thicknesses of whitener (Titanium Dioxide or Baryta). This darkening effect always leaves the original whites behind.

PE

Bob F. · Jun 4, 2008

Jos De said:
Rob, I'm using ilford multi-grade IV resin coated, developing in dektol and fixing with regular kodak fixer.

Fixer mixed at what strength and for how long in the fixer (with constant gentle agitation).

Concentrating on the fixer 'cos that does sound like insufficient (to the level of almost none) fixing.

Is the fixer fresh? Try a clearing time test to check that the fixer is working - i.e. see how long a piece of undeveloped film leader takes to clear in the working strength fixer. Should not take more than about a minute or so at paper strength (20 seconds at film strength). I sacrifice a roll of FP4+ for this and always do the test before using fixer - only needs a small piece cut off the roll each time.

Good luck, Bob.

RobC · Jun 4, 2008

And wash print properly after fixing.

Some drops of neat selenium toner on the white border of a fixed and and washed sample will tell tell you if the print has been properly fixed and washed.
If it stains the white then its likely its not fixed properly.
N.B. selenium on an incompletely washed print will also stain it if the fixer has acid in it.

fschifano · Jun 5, 2008

Regarding the dry down effect. It happens with resin coated well as with fiber based papers, though to a lesser degree. Don't believe me? Take a print made on RC paper and dip half of it in water. Compare. Some show the effect more than others, but every one I've tried shows some. Expect to see anywhere from a 5% to 15% darkening from dry down depending on the paper.

But I don't think that is your problem. Your description of the problem points more towards under fixing than anything else. Fixing with Kodak fixer (the powdered, sodium thiosulfate version) takes a while. You can't expect that stuff to fix out a print in the 30 seconds or so that it takes a rapid fixer to do the job, nor can you expect the capacity of the product to match that of a rapid fixer. So make sure you fix out the next batch of prints for at least 2 or 3 minutes with fresh fixer that hasn't been over worked and see if that doesn't make the problem go away.

Jos De · Jun 8, 2008

Thanks a bunch guys, I'll make sure to let you know how it turns out!

Troubleshooting: Darkening of prints.

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