Purple tone across negativegreenspun.com : LUSENET : Large format photography : One Thread
My last two batches of negatives have a purple tone, not clear. Normaly they turn out clear. Any thoughts?
-- tim kimbler (email@example.com), February 21, 1999
Could it be the famous T-Max purple stain, i.e. too little fixing, tired, depleted fix, etc.?
-- Sean yates (firstname.lastname@example.org), February 21, 1999.
Or it could be the slightly less famous variation between film batches, which sometimes give a slight overall purple tone, which is totally even across the whole film, and can't be removed with any amount of fixing or washing.
-- Alan Gibson (Alan.Gibson@technologist.com), February 22, 1999.
If it's on the back on the negative and purple, it's the anti-halitation layer. This is put on the back of the film to prevent reflecions behind the film from bouncing back on to the emulsion thus creating a double image, or simply lossing contrast. This is normally removed by the developer, but I have found that when using a drum to process them, I need to pre-soak to remove it completely. It's not such an issue when using a tray or a tank, because you have enough developer to wash it away, and you get to the back of the negative as evenly as the front. BTW, if you pre-soak, you will need to add time to your processing (about 20%).
To get rid of it on processed negatives, just soak it in water for about 5 minutes. It will dissolve away.
If the tone is pink and in the emulsion, check you fixer. It may be exhausted. Or fix a little longer. I usually fix for as long as I develop, with the same agitation, and I never have the problem any more.
To get rid of pink on non-T-Max film after its been processed, just re-fix in fresh fixer, and don't forget to re-wash. If it's on T-Max film, some pink is normal, but if it's excessive, try re-fixing.
-- Christopher H. Esser (email@example.com), February 22, 1999.
It is T-MAX film. I process for 6.5 minutes, (68) with XTOL using a JOBO 3010 drum and a Beseler motor base. I use 100ml per sheet of film, normaly 5 or 10 sheets at a time. I stop for 1 minute. I fix for 5 minutes. I wash for 5 minutes. My reading makes me believe I should be diluting the developer and processing for a longer time frame.
-- tim kimbler (firstname.lastname@example.org), February 22, 1999.
To remove anti-hlation dye, pre-soaking for 5 minutes. T-MAX films will require 6 minutes fixing(rapid type). Hypo clearing agent for 5 minutes before washing might help.
-- Shigehiro Ishii (email@example.com), February 24, 1999.
What kind of fix tim? Kodak recommends T-max fixer to overcome this problem. 5 minutes can surely be too short in my experience with purple tone.
-- Lot (firstname.lastname@example.org), February 24, 1999.
I use T-max sheet film and process for 8 mins, stop, fix for 3 mins normal Ilford dilution, hypo clear 2 mins, and wash for 10 mins. Stains gone. James
-- james (email@example.com), February 27, 1999.
The old rule of thumb was ..fix twice the clearing time. For roll film..drop the leader in the graduate of fix..and time how long it takes to go clear..then fix twice as long....total. This allows you to monitor the correct fixing time re: the actual strength of the fixer. For sheet film.. keep an old sheet or two or two (of the same emulsion) and cut off a piece to test with, as needed. I assume this would also work with TMax but this is a different film animal
-- C Matter (firstname.lastname@example.org), March 04, 1999.