Over fixed? what's the effect?

[59gilbert]

According to kodak's instructions, they recommend fixing time as short as possible. But I just want to make sure the film base is properly cleared. What is the effect if I fix the film for too long, say 15 minutes? Does that mean it need extra washing time? I started using hypo clearing agent in my recent 5 rolls. For one of them, I left it in the fixer and forgot! It was souped in the kodafix for 27 minutes, and so I hypo cleared for around 4 minutes instead of 90secs to 2 min as recommended. When I hanged it dry, the emulsion touching my fingers was coming off. The film felt extra soapy and slippery than others with shorter times. This particular roll is Fuji Neopan Presto 400.

What went wrong? Could somebody tell me? Thanks!

 

[M.A.Longmore]

.
Hi 59Gilbert,

I can't give you the answer to that question.
But I can give you a Welcome To APUG !!!
There are 44,178 other members, you will have an answer very soon.

Enjoy The Day


Ron
.

 

[Ian Grant]

Over fixing causes image bleaching, but this happens very much faster with papers than films.

With papers prolonged fixing also gives the silver/thiousuphate complexes longer to form bonds with the cellulose of the paper base, that doesn't happen with films.

Fuji's 400 ISO B&W film has a very soft emulsion, so too long in the fix & wash is not a good idea. Also it needs tight control of the temperature all stages or it gives excessive grain due to reticulation or micro-reticulation/grain clumping.

Ian

 

[Gerald C Koch]

Rapid fixers can cause bleaching when you exceed the manufacturers recommended times. How much bleaching depends on each kind of film This bleaching is most evident in the less dense portions of the negative. You can safely exceed the fixing time by 50% but I wouldn't go much past that. Non-rapid fixers are much slower in their bleaching action. You don't have to increase the wash time.

 

[removed account4]

if you want to see what over fixing can do ...
take a piece of photo paper, leave it the sun with something on it
like you are making a photogram ....
don't leave something living on it like plants, or stuff that might ooze ...
use keys or glass or whatever you have in your pocket ...

you will see an image appear on the paper in a while ...
take your paper with the photogram on it, and put it into your fixer ...
the image will pretty much vanish because the fixer has bleached it off of the paper.

sorry to hear of your film.
different films take different amounts of time to fix/clear.
you can always do a clear-test and clip off a piece of the film leader
and notice when it ... cleared .. double the time and you will be good to go.

have fun
john

 

[Worker 11811]

I don't know that the fixer by itself is what caused the emulsion to come off.

I think being under water for a long time is the more likely culprit:
1 min. in pre-wash. 5 to 10 minutes in developer. Another 1 to 2 minutes in stop bath+rinse. 27 minutes in fixer. 4 minutes in hypo clear. Finally, 15 to 30 minutes in water rinse+rinse agent.
That comes up to 60 to 90 minutes where the film was almost constantly in the chemistry and under water.

Soaking in water to soften the emulsion is part of what makes film developing work. If the emulsion didn't soften a certain amount, the chemicals wouldn't work as well, would they? But, after spending more than an hour under water, the emulsion softened all the way to the core instead of just the surface.

That's why I think your film was damaged the way that you report.

What you can do is try to dry the film VERY GENTLY. Let it dry out for a long time. A couple-few days, at least. Put it in a very clean environment where the temperature is stable. Then cross your fingers and hope that the emulsion doesn't reticulate or peel. You might very well be able to save the film or at least preserve it long enough to scan into digital files, make prints or create dupe negatives.

Now, as to being in the fixer for a long time... I think the damage has been done.

Think of it this way... At first, the fixer removes the undeveloped silver that isn't part of the image. Then, you get to a stopping point where you are supposed to take it out. But, if you leave it in, the fixer will keep "eating up" more and more silver until it starts "eating away" your image.

For short periods of time in the fixer, you probably don't notice that your images have been "eaten up."
For longer periods of time in the fixer, it will start eating away the details from the highlight areas of the image.
The longer the time you keep the film in the fixer, the more of those details will disappear.
I suppose, THEORETICALLY, if you left it in long enough, it could eat away your entire image. I don't really know. I'm only guessing.

Regardless, once any part of the image has been removed, I don't know of any way to put it back.
What is done, is done.

In the end, if it was my film, I would dry it really carefully and try to rescue any images off the film if I could. Then I would chalk the rest up to experience. If I was feeling adventurous and didn't have any special attachment to the images on the film I might experiment in the name of science if I was in the mood.

 

[Ian Grant]

Rapid fixers can cause bleaching when you exceed the manufacturers recommended times. How much bleaching depends on each kind of film This bleaching is most evident in the less dense portions of the negative. You can safely exceed the fixing time by 50% but I wouldn't go much past that. Non-rapid fixers are much slower in their bleaching action. You don't have to increase the wash time.

You can exceed the fixing times of films by around 3x with absolutely no discernible or measurable effect. In fact Kodak used to recommend doing just that with Tmax films, fix until the pink dye disappears. Silver chloride & chlorobromide emulsions are prone to bleaching, Bromide less do and iodo-bromide which are film emulsions even less so.

Ian

 

[59gilbert]

Thanks so much, guys! Thank god that the image is "still there." Not much damage except the part that my fingers gripped. I'll keep an eye on timing next time.

 

[Gerald C Koch]

How long a film can be left in a rapid fixer depends on the film type and various other factors. Very slow films will be effected more easily than faster ones. It is difficult to give a blanket time after which damage may occur. Therefore, I was very conservative in giving a maximum time.

 

[RalphLambrecht]

Thanks so much, guys! Thank god that the image is "still there." Not much damage except the part that my fingers gripped. I'll keep an eye on timing next time.

Gilbert

Excessive fixing acts like a proportional reducer. Shadows and highlights lose about the same percentage of density. You may not see the 'damage' by just looking at the negative. The recommendation is to fix as long a s necessary but as short as possible. A simple test can be conducted to establish the minimum fixing time. Cut off the film leader and dip it into the fixer. Measure the time it takes for the film to fully clear and double that time to get to your minimum fixing time.

I've never conducted a fixer test with film, but I've done it for paper, which is far more sensitive to overfixing than film due its much smaller grain size. After 8 min the effect was measurable, after 30 min it was visible.