Hypo Clearing Agent side-effects?
I have been developing film the same way for years using Agfa APX (25, 100) and the Efke KB line of roll films (25, 50 and 100). All has been souped in Rodinal at 1+50 or 1+100 with very few exceptions.
A friend handed me a package of Hypo Clearing Agent. He told me it would reduce my water usage to a minimum, as it reduces wash time to minutes. This sounded pretty appealing to me, as my wash time normally is 20-30 minutes. Water is such a precious commodity.
Excited I developed a roll of APX 25, and decided to try the Hypo out. When I took the roll off the reel, for the first time ever I had a completely clear film base. This was surprising to me, as I have been used to my negatives being a certain way for so long.
As you can tell, I haven't ventured into too many experiments with film chemistry.
This came as a complete surprise to me and Iamb wondering if it's normal that Hypo makes the filmbase completely clear.
I don't want to develop any more film with Hypo until this is "cleared up"
Saint Paul, MAN
I know this is going to sound crazy, but the manner in the way you state the question leads me to ask this one.. Did you use the HCA as a developer?
If so, this is the problem as it is to be used after fixer.
If not, clear film would lead me to wonder if the film was exposed.
If you want to cut down on the wash times, check out Ilford's recommendation on film washing at their site.
Originally Posted by huggyviking
Thomas, I think you misunderstood your friends use of Hypo Clearing Agent. It is not Hypo, as it is not a fixer. The purpose of HCA is to remove excess hypo to aid in reducing wash times. You would fix film/paper like you always do, then rinse, then place in HCA for x amount of time, then wash. Do a search on HCA or Hypo Clearing Agent, to find more info on times, etc.
Now all you need to do is wash out the HCA.
Everything is analog - even digital :D
thank you for your answers. I have developed the film as I normally do.
2. Water rinse ~ 2min (instead of stop bath)
3. Fix ~ 2min 30sec
4. Water rinse ~ 30sec
5. Hypo Clearing Agent ~ 5min
6. Water rinse ~ 3 min
7. Photo Flo
8. Dry film over a humidifier
Everything as normal except for a shorter rinse and the added Hypo Clearing bath.
As 'Jdef' suggested, the clear film base is normal. Yes, other than that the negs look about normal. They will probably print differently, I suspect I will need to reduce contrast some - which is not at all something I want to deal with.
'Tom Hoskinson' - you suggested that all I need to do is to wash out the agent. Does that mean that HCA is a bad thing that will limit the archival qualities of the film, or does it simply mean that I have an easy job ahead of me washing that out instead of
washing all of the fixer out?
Apart from all this - would the sole benefit of HCA be to rid the fixer from the emulsion quicker than a water bath? Or are there other benefits as well? (I realize that some people perhaps like the totally clear film base, so for them that would be a benefit).
Saint Paul, MN
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thanks for your time. I was actually aware of Ilford's film washing recommendations, and I use the technique they describe, only for a lot longer than they recommend.
My theory is that water needs to be in contact with the emulsion for a certain period of time to penetrate it and wash it out, no matter how much you agitate.
I am probably wrong about this, but better safe than sorry - that's my motto.
Anyway, thank you for your help. I appreciate it very much.
Saint Paul, MN
Originally Posted by ann
i mis-understood something along the way, i thought you meant the whole roll of film was clear. Isn't it interesting how easy it is to mis understand and then we wonder why communication is so difficult.
A friend handed me a package of Hypo Clearing Agent. He told me it would reduce my water usage to a minimum,
I would use this for shortening the wash time for fibre papers. This would certainly reduce the wash time and ensure residual fixer is removed prior to selenium toning.
Cogito, ergo sum.
you have stated that in your process the wash time is 3 minutes. Regardless to what Ilford states I would increase the wash time to at least 10 minutes. Better safe than sorry some where down the line. Are you willing to bet your images that 3 minutes is long enough?
I use hca for fibre prints rather than film. Wash temperature is an important consideration along with time too.
There are 10 types of people in this world - those who understand binary and those who don't.