When I test the clearing of the base of T-max 100 (in Paterson fixer, diluted 1:3) the base gets clear pretty fast (about 35 seconds) but when I then double that time and then wash it, it leaves the film blue. However, if I extend the fixing time to 4x times the clearing time, I can wash away all the colour. So, here's my questions:

1) Is the definition of a clear film base different for T-max 100 and should include removal of colour as well?

2) Do the test strips of film have to be immersed in developer first in order to get the "true" clearing time?

Until I get an answer on this I'll stick to Tri-x and Fuji Neopan 400 :-)

-- Peter Olsson (peter.olsson@lulebo.se), August 20, 1999

Answers

Last time I looked, Kodak didn't recommend that you base fixing on a multiple of clearing time. Instead, they suggest 3-5 minutes in Kodak rapid fixer. Your 2 minutes sounds like far too little.

This might be because t-grain films do indeed 'clear' in a strange way. I have suggested a mutiple of three times the clearing time, and I do mean a total clear (including colour).

In practice, I always fix for 10 minutes. This may be overkill, but I believe it is harmless. If a t-grain film takes 3 minutes or more to totally clear, it is time to discard the fixer.

-- Alan Gibson (Alan.Gibson@technologist.com), August 20, 1999.

Alan has it right...to clear the magenta stain from Tmax emulsions, extended fixing is required. I use the Polymax fixer, diluted 1:3 for 10 minutes. Any residual stain will then come off in the wash. Be aware that if you re-use your film fixer for printing...Tmax films exhaust the fixer faster than non T-grin emulsions.

-- Tony Novak-Clifford (photoho@mauigateway.com), August 20, 1999.

I use a two bath fix for all film and paper, Kodak or Sprint rapid fixer, no hardener. I fix Tmax for 2 minutes in each bath. When I put the film in Heico Perma Wash (after a water rinse) most of the color comes out. The rest of the color comes out in the final rinse. I've never had purple Tmax negs.

-- Tim Brown (brownt@ase.com), August 20, 1999.

Films should be fixed for two to three times the clearing time, usually the latter for t-grain type films. Clearing is defined as removing the (unexposed) silver halide density from the film, no milkiness, ignoring any blue of purple cast. The colors are leftover sensitizing dyes and can be ignored or removed. To remove leftover dye just use a wash aid, as you should be doing anyway. You can easily make a wash aid by dissolving a tablespoon of sodium sulfite in a quart of water; after fixing, bathe the film in the wash aid for two to three minutes. Then give the standard wash; you'll have no purple or blue negs. There's NO NEED to fix forever to get rid of the dye. Also, one caveat; commercial wash aids often specify a very short wash time, such as five minutes. Although I haven't tested, I don't buy that; I don't think there's really sufficient changes of water in such a short time, so I give the standard 20-30 minute wash.

-- John Hicks / John's Camera Shop (jbh@magicnet.net), August 20, 1999.

Uh? How thick is that emulsion? Pretty thin so why does it take so long to fix and wash? Do the testing and find out how long it takes. That's the only way. Stop taking someone elses word for it. James

-- james (james_mickelson@hotmail.com), August 21, 1999.

Well, here's my two-cents worth: I don't recommend extended fixing times, because at some point the fix will start dissolving not only silver halides but also image silver. I have found that three or four minutes in the standard dilution of Perma-Wash after normal fixing will get rid of the magenta stain from T-Max, and it reduces the wash time to boot.

-- Ed Buffaloe (edbuffaloe@unblinkingeye.com), August 23, 1999.

It takes me 5-6 minutes in Kodak Fixer and the use Heico Perma Wash to remove the tint... so I wouldn't fix for under 5 minutes with T- Max. I have found it easier to remove the stain from TMZ than TMX, and I blame this on long devcelopment times for TMZ.

-- John O'Connell (joconnell@adelphia.net), August 26, 1999.