Photo Flo In Presoak OK for PMK?

[Drew Wiley]

Sometimes a tiny amount of EDTA in the dev might be better in terms of overall evenness of dev, if you can't control it in a more conventional manner.

[Rick A]

I've used a drop or two of Edwal LFN in my developer when using D-76 in small tanks to keep it from foaming, never in pre soak though.

[PRJ]

I can make a case for and against it. It just depends. Back in the day the only way to avoid air bells on HIE was to add LFN to the developer. On the other hand, LFN combined with glycol (if you mix your Pyrocat in Glycol) is a disaster with inversion developing. You might as well run a bubble bath. I imagine PhotoFlo would have a similar effect but I haven't used it in years so YMMV. I doubt there would be a problem in tray processing though.

If you have not had any problems with PhotoFlo with Pyrocat I can't think of a reason why PMK would be any different. Then again if you don't have problems with air bells I don't see a reason to use it either.

[neil poulsen]

I thought I read that one of the reasons Ilford does not suggest a pre-soak is that their film's emulsion already has a surfacant in it to aid an even reception of the developer into dry emulsion.

But this info needs back-up.

Also my understanding after speaking with an Ilford technician. He said that the film contains wetting agents. So, I don't use a presoak with that film.

[Drew Wiley]

Neil - we're going around in circles on that one. It's been repeatedly addressed in numerous previous posts. Since I've charted these water for decades myself, it's "Damn the torpedoes, full stem ahead!" Ilford film is no different than any other brand in this respect, and I always pre-wet that too, every type. A case has been made elsewhere for certain microfilms and their specialty developers not to pre-wet, but that's an outlier topic. I even routinely pre-wetted for TechPan with total success.

Maybe Ilford was just trying to improve the odds of those who don't take the extra step of pre-wetting, and was using this as a feather in their marketing cap. But that in itself is not a negation of the positive value of pre-wetting. No different than their tech shees recommending this or that developer which they specifically market as well. Doesn't mean many other developers don't work equally well, or perhaps even better.

[Michael R]

There are basically two situations in which pre-soaking is of possible merit. (1) where the film cannot be uniformly wetted with developer in a short amount of time, (2) where film surfaces might come into contact before they are thoroughly wet.

Ilford advises against pre-soaking in general since it results in removal of the incorporated wetting agent. This will really only potentially matter in cases where the film will not be immersed in the developer quickly/uniformly.

[Tin Can]

Agree

No presoak

No soap either

[Greg]

When I was a student at The Rochester Institute of Technology in the 1970s, I took a course in Photographic Sensitometry under Prof. Hollis Todd and Prof. Hill. The topic of using a Photo Flo solution in the presoak came up. I do remember that it was a definite NO to do this... sorry I can't recall the reason why. Possibly not to use with automated processors? The "current" thinking back then was actually not to presoak the film, but to start the development process by putting the film directly into the developer with a full minute of continuous agitation. For me, I have always used a plain water presoak per the recommendation of possibly George E. DeWolfe.

[esearing]

my rule of thumb for FP4 and HP5 - Presoak in plain water if using diluted developer or developer can not be added to tank within 10 seconds, not required if using full strength or small tanks/trays. It can take me 45 seconds to fill an 1800ml tank for my 5x12 and 15 seconds for the SP445, so I always presoak for about 5 mins; which gives me time to adjust water to final temperature and add the parts A and B for Pyrocat M . The presoak seems to do a good job of removing the dye so it doesn't end up coloring my fixer.

I have eliminated photoflo entirely but have good water quality and do not get water spots.

[Tin Can]

Thanks for your complete answer

It makes sense, as it takes a long time to get it all wet

My process gets my film of any size fully in developer and wet in under 1 second to 3 seconds

Even 14X36" film

my rule of thumb for FP4 and HP5 - Presoak in plain water if using diluted developer or developer can not be added to tank within 10 seconds, not required if using full strength or small tanks/trays. It can take me 45 seconds to fill an 1800ml tank for my 5x12 and 15 seconds for the SP445, so I always presoak for about 5 mins; which gives me time to adjust water to final temperature and add the parts A and B for Pyrocat M . The presoak seems to do a good job of removing the dye so it doesn't end up coloring my fixer.

I have eliminated photoflo entirely but have good water quality and do not get water spots.