Photo Engineer
Subscriber
Having been reading a lot of Kodak data sheets recently during the debates over washing, fixing, stops and the like, I ran across something that kind of put some things into perspective for me.
See here on page 9 for a comment by Kodak: http://www.kodak.com/global/en/professional/support/techPubs/f4016/f4016.pdf
New films use a combination of layered dyes and dyes complexed with Osmium compounds (2 electron sensitization). These dyes can leave a pink or magenta stain in some films. Since dyes have a positive charge, acid fixers are more prone to this. Since high Iodide and strong dyes inhibit fixation, longer fix times and longer wash times are needed, especially if you season or re-use your fixer and especially if it is acid or neutral.
Kodak is aware of this change, but it is necessary for us to be aware of the fact that a magenta tint may be due to underfixing and/or underwashing. This is probably a warning flag for all of us.
PE
See here on page 9 for a comment by Kodak: http://www.kodak.com/global/en/professional/support/techPubs/f4016/f4016.pdf
New films use a combination of layered dyes and dyes complexed with Osmium compounds (2 electron sensitization). These dyes can leave a pink or magenta stain in some films. Since dyes have a positive charge, acid fixers are more prone to this. Since high Iodide and strong dyes inhibit fixation, longer fix times and longer wash times are needed, especially if you season or re-use your fixer and especially if it is acid or neutral.
Kodak is aware of this change, but it is necessary for us to be aware of the fact that a magenta tint may be due to underfixing and/or underwashing. This is probably a warning flag for all of us.
PE