Kodak T-Max 400 Fixing Query

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Russell W. Barnes

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Hello all,

I've just ordered five rolls of TMax 400 120 film to give it a go, and I intend developing it in Ilford ID-11, agitating and fixing the Ilford way.

I notice from the Kodak TMax datasheet that '...your fixer will be exhausted more rapidly with this film than other films...'

Why is this? How much more quickly will it be exhausted?
 
I have been using TMax 400 for some time now. I tend to use the same fixer dilution for 3 films and then discard. I have not seen any difference for 3 films but if the data sheet says so I believe it. I make a new solution after 3 films. Maybe it is me being overcautious.
 
There's no need to discard fixer preventively, do a clearing test with a film leader (I think Roger Hicks has instructions on his website, don't listen to instructions that tell you to just throw a piece of film in, it's important to have a bit of it fixed for longer, to compare to), use twice or, for safety, three times the clearing time. I've had good luck fixing at room temperature in summer, which makes it work a bit faster, I'm thinking about warming my fix in winter as well, but thats a question of how much risk one wants to take.
 
If the film base still has a pink tone after fixing, rinse the film in not too cold water (but not too hot!). The pink tone will disappear. But if the film is still milky just go on fixing it for a wile before washing.


Erik.
 
Russell W. Barnes said:
Hello all,

I've just ordered five rolls of TMax 400 120 film to give it a go, and I intend developing it in Ilford ID-11, agitating and fixing the Ilford way.

I notice from the Kodak TMax datasheet that '...your fixer will be exhausted more rapidly with this film than other films...'

Why is this? How much more quickly will it be exhausted?
Click to expand...

Why does it deplete fixer faster? Beats me, but I think all tab grain films do it.

It's a good idea to test film leaders for fixing strength to establish a reasonable number of rolls to attempt before discarding your solution. Your results may be slightly different than other people, and there is no need to guess.
 
Not sure why it depletes your fixer more rapidly but it does. I am pretty sure it involves the pink or magenta colored stain used with these films since it seems to take longer for the fixer to clear this color.

Because it is so easy to do I regularly do clip tests of fixer to establish my clearing times. When working with Kodak TMAX 400 (4x5 sheet film) I typically fix for at least 5 minutes with fresh Photoformulary TF5 fixer (which is a tad more than twice the clearing time for me.) The clearing time does slowly increase as you fix more films.

Do your own clearing tests to establish your fixing times and you will undoubtedly notice the same results, or similar ones.

Clip tests or clearing tests are so simple to do I don't know why everyone doesn't do it regularly. It is the only way to be sure you are actually completely fixing your films. As already mentioned, Roger Hicks explains the test quite nicely at this link. http://www.rogerandfrances.com/subscription/fixer exhaustion.html

I use an old plastic Cool Whip container to do the test which I keep on the shelf specifically for this purpose. Any small plastic container will work though. It takes me less than 5 minutes (which includes all the prep involved) to know without doubt how healthy my fixer is.
 
I can confirm this too. From my tests Tmax400 depletes Ilford rapid fixer about 20% faster than HP5+.
 
Thanks for all that, folks. I do test my fixer with a little bit of cut-off film every so-often in a bottle-top or jam-jar lid and double the time it takes to clear. Well, I've done it on 35mm but never factored in my 120 stuff, so I'll use the little bit of film that's left after I cut it off the backing paper.

I'll check my fix mix after I've used these five rolls of TMax up.
--

Kind Regds,

R.
 
Monosize flat (t-grain) films have a different balance of silver salts in the emulsion, including a lot more silver iodide, than is contained in traditional mixed size cubic grain films. This requires more fixer to effectively fix, and is only fixed properly by ammonium thiosulfate (rapid) fixer, not by traditional sodium thiosulfate (hypo) fixer.

Fix for twice the clearing time and discard either when the clearing time doubles:
http://www.rogerandfrances.com/subscription/fixer exhaustion.html
or after the fixer gets to 6g/L silver (use hypo check or silver estimating strips).

Marty
 
And just to reinforce "Pioneer's" remark , Photographers' Formulary specifically remarks that T-Max films take 50% to !00% longer to fix than other films !
Regards,Peter
 
I'll echo what Moto-Uno says -- in my experience (this is my most used film), I just double my fixing time with TMax films, otherwise it comes out completely magenta.
 
Freakscene said:
Monosize flat (t-grain) films have a different balance of silver salts in the emulsion, including a lot more silver iodide, than is contained in traditional mixed size cubic grain films. This requires more fixer to effectively fix, and is only fixed properly by ammonium thiosulfate (rapid) fixer, not by traditional sodium thiosulfate (hypo) fixer.

Fix for twice the clearing time and discard either when the clearing time doubles:
http://www.rogerandfrances.com/subscription/fixer exhaustion.html
or after the fixer gets to 6g/L silver (use hypo check or silver estimating strips).

Marty
Click to expand...

I'm glad Marty pointed this out. There is more to fixing film than clearing it. The fixer eventually becomes saturated with silver, after which it can't hold any more. After fixing film, I pour a little bit of the fixer, say 1/2cc, into a small graduate cylinder. I add one drop of hypo check. If the fixer is saturated, some silver will precipitate out and form a white cloud. Then it's time to throw it away. This will happen even before the fixer is no longer clearing the film.
 
Freakscene said:
Monosize flat (t-grain) films have a different balance of silver salts in the emulsion, including a lot more silver iodide, than is contained in traditional mixed size cubic grain films. This requires more fixer to effectively fix, and is only fixed properly by ammonium thiosulfate (rapid) fixer, not by traditional sodium thiosulfate (hypo) fixer.

Fix for twice the clearing time and discard either when the clearing time doubles:
http://www.rogerandfrances.com/subscription/fixer exhaustion.html
or after the fixer gets to 6g/L silver (use hypo check or silver estimating strips).

Marty
Click to expand...


Thanks for the clearer explanation Marty.
 
I get rid of most of the magenta layer by pre-soaking the film for about 10 minutes.
Then I fix 7 instead of standard 5 minutes.
 
Hmmm, I fixed a roll of expired T-max three weeks ago and the next time I used the fixer there was a lot of black sediment floating around in the fixer.
I thought the fixer might have oxidized because I didn't tighten the cap enough......might just be a coincidence.
The fixer was still good for fixing the next film within 5 minutes though.
 
Rob-F said:
I'm glad Marty pointed this out. There is more to fixing film than clearing it. The fixer eventually becomes saturated with silver, after which it can't hold any more. After fixing film, I pour a little bit of the fixer, say 1/2cc, into a small graduate cylinder. I add one drop of hypo check. If the fixer is saturated, some silver will precipitate out and form a white cloud. Then it's time to throw it away. This will happen even before the fixer is no longer clearing the film.
Click to expand...

There is one extremely important thing to always remember: the fixer will keep fixing long after it is no longer fixing properly or in a way that is safe for the long-term storage of your film.

What fixer does is:
AgX + 2 S2O32− → [Ag(S2O3)2]3− + X−
AgX + 3 S2O32− → [Ag(S2O3)3]5− + X−
where X is a halide (bromide, chloride or iodide). The second reaction, which needs more thiosulfate, predominates in mono size flat emulsions like TMax films.

Having excess thiosulfate is vital for removing all the unexposed silver. Once you have finished fixing, you then need to be able to wash all the silver thiosulfate out of the film. If there is more than 6g/L of silver in the fixer enough will remain that your film is likely to deteriorate unduly over a timeframe where if you had fixed it properly it would not deteriorate.

This is the misleading part: fixer will keep clearing film and making it look like it is fixed after the thiosulfate concentration has dropped to a point where it is not fixing the silver halides efficiently and where it contains too much silver to be effectively washed out. So, either time, or measure. Dump when the clearing time doubles or the silver concentrations reaches 6 g/L.

Mr_Flibble said:
Hmmm, I fixed a roll of expired T-max three weeks ago and the next time I used the fixer there was a lot of black sediment floating around in the fixer.
I thought the fixer might have oxidized because I didn't tighten the cap enough......might just be a coincidence.
The fixer was still good for fixing the next film within 5 minutes though.
Click to expand...

If fixer goes off it is a reduction reaction, rather than oxidation. The reduction and sulfur precipitation can occur with age, irrespective of use. Thiosulfates are stable only in neutral or alkaline solutions, but not in acidic solutions, due to decomposition to sulfite and sulfur, the sulfite eventually being dehydrated to sulfur dioxide:
S2O32− (aq) + 2 H+ (aq) → SO2 (g) + S (s) + H2O
The sediment will be white or pale yellow - it is amorphous sulfur (S) and it usually smells a bit like rotten eggs because the process also produces sulfur dioxide (rotten egg gas). This occurs spontaneously over time, but is accelerated by use. Silver will never precipitate out of your fixer without a serious chemical nudge.

The black stuff in your fixer after you fixed TMax film is a mixture of the antihalation and anti friction/static layers. The pink stuff is one of the sensitization dyes, and if your film is properly fixed but still pink, can be removed with a little sunlight exposure. But don't overdo it, or the sun might damage your negatives.

Now, go take some photos. And later, when you develop the film, time clearing or measure the silver in the fixer, and forget all this. Kodak worked this out a long time ago. All you need to do is run with it.

img759-Edit.jpg

On Plus-X (sniff) fixed with Fomafix liquid 1+5 (as recommended by Foma) for 5 minutes (2x the clearing time).

Marty
 
Freakscene said:
[...]

This is the misleading part: fixer will keep clearing film and making it look like it is fixed after the thiosulfate concentration has dropped to a point where it is not fixing the silver halides efficiently and where it contains too much silver to be effectively washed out. So, either time, or measure. Dump when the clearing time doubles or the silver concentrations reaches 6 g/L.


[...]
The sediment will be white or pale yellow - it is amorphous sulfur (S) and it usually smells a bit like rotten eggs because the process also produces sulfur dioxide (rotten egg gas). This occurs spontaneously over time, but is accelerated by use. Silver will never precipitate out of your fixer without a serious chemical nudge.
[...]

Marty
Click to expand...


1. Thanks, important reminder.


2. I've had a lot of silver coat the inside of my bottle, looked neat (Tetenal fixer). Started after only a few rolls, and still worked very quickly, so I kept using it a while. Do I need to worry?
 
Marty, have you been using Fomafix for fixing FB papers as well? I'm asking because the only dilution Foma gives is 1+5 (and 1+4 for macine processing) so I wonder if their fixer is perhaps weaker (containing less ammonium thiosulfate) in comparison to say Hypam. I tend to fix FB papers in two baths of Hypam/Ilford Rapid Fix at 1+9, each for 1'.

BTW, 2-bath fixing works very well for T-MAX films.
 
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