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ryanmills
1-Mar-2013, 18:58
whats the average number of 4x5 sheets you can do before you dump it? Tech sheet says 24 rolls of 35mm when mixed at a liter. Curious what people average.

Jerry Bodine
1-Mar-2013, 21:16
A 36-exposure roll is usually considered to be the same as one 8x10, or four 4x5. That works out to 96 4x5 sheets per liter of 1+4 fixer w/o replenishing. I personally don't push it that close, since fixer is not real pricey. Also pay attention to the storage information provided in the tech sheet.

jnantz
1-Mar-2013, 21:40
i don't count sheets but do a "clip test"
i take a 1" square sheet of film ( or piece of film leader ) exposed in daylight
( or roomlight ) and see how long it takes it to clear to clear film base.
i double that number for my total fix time between 2 baths.
when bath #1 takes 2x the original time it is time for new fixer ..
#1 gets de-silvered, #2 becomes mynew #1 and i mix a new batch #2 ..
i don's use ilford fix but the clip test works with all fixer ...

good luck !
john

Tony Evans
1-Mar-2013, 21:46
For 4 sheets (Taco), 1:40 for 800 ml works fine, one shot.

Doremus Scudder
2-Mar-2013, 10:34
i don't count sheets but do a "clip test"
.... see how long it takes it to clear to clear film base.
i double that number for my total fix time between 2 baths.
when bath #1 takes 2x the original time it is time for new fixer ..
#1 gets de-silvered, #2 becomes my new #1 and i mix a new batch #2 ..
i don's use ilford fix but the clip test works with all fixer ... good luck !
john

Ryan,

I have a very similar fixing regime to John in the quote above.

When I first started processing, fixing was one of the "mysteries" that I just couldn't seem to get my head around; there were often many recommendations for capacity, even from the same manufacturer, plus one and two bath fixing.

I'll try and spare you the confusion and give a simplified version of what it has taken me a while to learn.

First, as you fix film or paper, by-products build up in the fixer. These are silver compounds dissolved out of the film or paper. These by-products gradually turn into compounds that will not wash out of the emulsion. It is the "acceptable level" of these by-products in the fixer that mostly determines fixer capacity. Of course, if the fixing chemicals themselves deteriorate, which does happen with time, the fix will go bad as well (hence lifespans for fixer in bottles, trays, etc.), but for freshly-mixed fixer, capacity is a function of the amount of insoluble silver compounds in the fixer.

Second, there are many "standards" about what the acceptable level of these compounds are. There are standards for "commercial," "general-purpose," "optimum permanence," etc. Acceptable levels of insoluble silver for "commercial" photography usually refers to now defunct newspaper photography, and is not really that permanent. Likewise the levels for "general purpose" use allow more undissolved silver compounds in the film/paper than when processing for "optimum permanence." And, there are different standards for film and paper.

For negatives that don't have to last more than 50 years, I imagine that following the guidelines for "general purpose" would be just fine. If you have negatives with historical value, you would likely want to process for optimum permanence so they'll last a couple hundred years or more.
For exhibition prints, that should last for centuries, processing for optimum permanence is paramount.

Ilford gives the amounts of allowable dissolved silver in a fixing bath in grams per liter of fixer. Unfortunately, there's no practical way for us photographers to make these kinds of measurements. So, we are stuck relying on throughput recommendations or clip tests to see if our fixing baths are exhausted.

But first, we have to decide what level of fixing is acceptable for our purposes. Following the Ilford recommendation for film throughput or using the clip test is a fairly common way to deal with film fixation. The recommendation you quote (24x13536 for 1 liter of Rapid Fix mixed 1+4) works out to 96 sheets of 4x5 film per liter. This is for "general purpose" or "commercial" standards and, according to Ilford, the level of undissolved silver can rise to 8-10 grams per liter of fixer without doing harm.

Many of us think that this is a bit too optimistic and use our fixer at about half of that recommended throughput or use two-bath fixing for optimum negative permanence.

Fixing for optimum permanence almost always requires two-bath fixing to be economical.

All this can be rather daunting at first. Fortunately for you, there is a great document on the Ilford website that will answer all your questions and give you all the information you need to fix film or prints to fairly high standards. You just need to download it and take the time to read and digest it. It is a great reference.

You'll find it here: http://www.ilfordphoto.com/Webfiles/2006130218312091.pdf

The only departures I make from the Ilford recommendations are 1) I use two-bath fixing for my film as well as my prints when doing large batches. When doing smaller batches, I halve the Ilford recommendation (i.e., 48 4x5 sheets or less per liter of fixer mixed 1+4). This because of some other research I've read that finds that 8-10 grams per liter of dissolved silver in the fixing bath is really too high for optimum permanence for film. 2) I fix for three times the clearing time, not two for a couple of reasons. I've read that many modern films take longer than the 2x-clearing time to fix properly; film can be fixed longer than minimum time with no ill effects unless you leave it in the fix for 20 minutes or more; fixing longer helps get rid of the pesky pink stains that many films have.

Hope this helps,

Doremus

ryanmills
2-Mar-2013, 13:28
Thank you Doremus,

I have issues with the pink and I might try the double fix bath. Do I understand correctly that you have both baths mixed at 1:4? And if 20 mins is the max fix time, would would time would you recommend starting with in each the bath? Right now im in the fix for 4 mins, if im doing two baths should I just do each at 4 or bump is up to maybe 6 mins per bath to get the 3x?




Ryan,

I have a very similar fixing regime to John in the quote above.

When I first started processing, fixing was one of the "mysteries" that I just couldn't seem to get my head around; there were often many recommendations for capacity, even from the same manufacturer, plus one and two bath fixing.

I'll try and spare you the confusion and give a simplified version of what it has taken me a while to learn.

First, as you fix film or paper, by-products build up in the fixer. These are silver compounds dissolved out of the film or paper. These by-products gradually turn into compounds that will not wash out of the emulsion. It is the "acceptable level" of these by-products in the fixer that mostly determines fixer capacity. Of course, if the fixing chemicals themselves deteriorate, which does happen with time, the fix will go bad as well (hence lifespans for fixer in bottles, trays, etc.), but for freshly-mixed fixer, capacity is a function of the amount of insoluble silver compounds in the fixer.

Second, there are many "standards" about what the acceptable level of these compounds are. There are standards for "commercial," "general-purpose," "optimum permanence," etc. Acceptable levels of insoluble silver for "commercial" photography usually refers to now defunct newspaper photography, and is not really that permanent. Likewise the levels for "general purpose" use allow more undissolved silver compounds in the film/paper than when processing for "optimum permanence." And, there are different standards for film and paper.

For negatives that don't have to last more than 50 years, I imagine that following the guidelines for "general purpose" would be just fine. If you have negatives with historical value, you would likely want to process for optimum permanence so they'll last a couple hundred years or more.
For exhibition prints, that should last for centuries, processing for optimum permanence is paramount.

Ilford gives the amounts of allowable dissolved silver in a fixing bath in grams per liter of fixer. Unfortunately, there's no practical way for us photographers to make these kinds of measurements. So, we are stuck relying on throughput recommendations or clip tests to see if our fixing baths are exhausted.

But first, we have to decide what level of fixing is acceptable for our purposes. Following the Ilford recommendation for film throughput or using the clip test is a fairly common way to deal with film fixation. The recommendation you quote (24x135–36 for 1 liter of Rapid Fix mixed 1+4) works out to 96 sheets of 4x5 film per liter. This is for "general purpose" or "commercial" standards and, according to Ilford, the level of undissolved silver can rise to 8-10 grams per liter of fixer without doing harm.

Many of us think that this is a bit too optimistic and use our fixer at about half of that recommended throughput or use two-bath fixing for optimum negative permanence.

Fixing for optimum permanence almost always requires two-bath fixing to be economical.

All this can be rather daunting at first. Fortunately for you, there is a great document on the Ilford website that will answer all your questions and give you all the information you need to fix film or prints to fairly high standards. You just need to download it and take the time to read and digest it. It is a great reference.

You'll find it here: http://www.ilfordphoto.com/Webfiles/2006130218312091.pdf

The only departures I make from the Ilford recommendations are 1) I use two-bath fixing for my film as well as my prints when doing large batches. When doing smaller batches, I halve the Ilford recommendation (i.e., 48 4x5 sheets or less per liter of fixer mixed 1+4). This because of some other research I've read that finds that 8-10 grams per liter of dissolved silver in the fixing bath is really too high for optimum permanence for film. 2) I fix for three times the clearing time, not two for a couple of reasons. I've read that many modern films take longer than the 2x-clearing time to fix properly; film can be fixed longer than minimum time with no ill effects unless you leave it in the fix for 20 minutes or more; fixing longer helps get rid of the pesky pink stains that many films have.

Hope this helps,

Doremus

photobymike
2-Mar-2013, 13:57
Jeez alot about nothing.. Go to Freestyle and get a little bottle of fixer test.. A cloudy drop and your fixer is gone or just taste it...if tastes salty its good

jnantz
2-Mar-2013, 19:08
Jeez alot about nothing.. Go to Freestyle and get a little bottle of fixer test.. A cloudy drop and your fixer is gone or just taste it...if tastes salty its good

"hypo check" will give a false read in a lot of fixers

photobymike
2-Mar-2013, 19:53
I did not know that... so the taste test is flawless......lol lol
I dont reuse fixer ..yea i know a waste but am guaranteed performance of the fixer if mixed right and used per instructions.

Doremus Scudder
3-Mar-2013, 03:04
Thank you Doremus, I have issues with the pink and I might try the double fix bath. Do I understand correctly that you have both baths mixed at 1:4? And if 20 mins is the max fix time, would would time would you recommend starting with in each the bath? Right now im in the fix for 4 mins, if im doing two baths should I just do each at 4 or bump is up to maybe 6 mins per bath to get the 3x?

Ryan,

You really need to be a bit more discerning/discriminating. I really wasn't saying that 20 minutes was maximum fixing time, but that leaving film in the fixer much longer than needed for complete fixing will have only a minimal effect. You should fix for the right time for the state of your fixer and maybe a bit more for a "safety factor," or to help eliminate the pink cast a bit. It won't hurt to fix longer, say 10 minutes or so, if that helps get rid of the pink cast, but a shorter time would be more optimal.

As for what time to start, it's been covered, but I'll go over it again: Do a clip test (like John recommends and which is explained in detail in the Ilford document I linked to and which you should have now). Minimum fixing time is 2x the clearing time or the manufacturer's minimum fixing time, whichever is greater. I add about 10% as a safety factor with film, since (as I mentioned) fixing the film a bit longer than minimum does no real harm. Note, you need to 1) do a clip test in fresh fix to establish that clearing time and 2) do a clip test before each batch you use the used fixer for to determine the fixing time for that particular batch.

If I were you, I'd just use one fixing bath until you get the hang of things and understand the processes better. My recommendation: mix a liter of Ilford Rapid Fix at 1+4, do a clip test before each fixing batch to determine your fixing time. Toss your fixer when it gets too old (read the Ilford directions) or when the clearing time for the clip test is 2x that in fresh fix (that's why you test fresh fix and note the time). Be conservative here; toss the fix early instead of too late. I rarely let my fix get to the 2x clearing time in fresh fix; I toss it earlier and mix new.

A two-bath fixing scheme will not eliminate the pink cast of some films any faster than a single bath. It is for optimum permanence and for large volumes. You likely do not need to do that now. If you do choose two-bath fixing, simply divide the total fixing time evenly between the two baths.

And, all of this and more is explained in exquisite detail in the Ilford Rapid Fix sheet I linked to above. Just read that.

Best,

Doremus

cyrus
5-Mar-2013, 12:19
Jeez alot about nothing.. Go to Freestyle and get a little bottle of fixer test.. A cloudy drop and your fixer is gone or just taste it...if tastes salty its good

Actually it would be best to stop using the fixer BEFORE the fixer test drop results in cloudy precipitate. By the time the cloudiness appears, the fixer is done. Using exhausted fixer will not only not fix properly, but will also introduce fixer byproducts into the paper which are not washable.

Arne Croell
5-Mar-2013, 16:10
The actual silver content of the fixer can be checked with the Tetenal Fixing bath kit: http://www.freestylephoto.biz/101243-Tetenal-Fixing-Bath-Test-Kit-100-Strips
It is not cheap, though, at $ 0.835 per test strip.

ic-racer
5-Mar-2013, 21:12
whats the average number of 4x5 sheets you can do before you dump it? Tech sheet says 24 rolls of 35mm when mixed at a liter. Curious what people average.

I use the Ilford ammonia thiosulfate fixer one-shot. I use about 20 ml per 8x10 equivalent then throw it out.