Presoak or not?

normmamiya · Mar 19, 2008

Hi

I want to use FP4+ with PMK. It's recommanded to presoak the film. Why?
What is the influence to presoak or not for this combination? What is the
effect for the others combinations? Is the presoak influence the development
time?

Trevor Crone · Mar 19, 2008

Presoak is valuable in allowing the developer to react quickly and evenly on the emulsion. It's also valuable in preventing the formation of 'air-bells', tiny bubbles forming on the film. The one time I failed to presoak I got these dreaded 'air-bells' which print as tiny dark spots/circles.

Ian Grant · Mar 19, 2008

Presoak is a total waste of time and unnecessary.

That's the other side of the debate no B&W film manufacturer recommends it. This is the 3rd or 4th thread on this subject in as many days

More seriously I tried a presoak, it made zero difference, I process many hundreds of films per year with no problems using staining developers. It's what works for you that matters.

Ian

Saganich · Mar 19, 2008

A presoak will influence the development time by generally shortening them a bit. Presoak influences the curve as well depending on the film structural characteristics and the developer chemistry.

jim appleyard · Mar 19, 2008

Saganich said:
A presoak will influence the development time by generally shortening them a bit.

I've read and done just the opposite, to add 1 minute to the time.

Ian Grant · Mar 19, 2008

Quite right Jim, a pre-soak means the dev will not be drawn immediately into the film, so slows things down and requiring a longer developing time to compensate. It also has little if any influence on the film curve except for Chris as he's under-developing.

Ian

Christopher Walrath · Mar 19, 2008

A presoak will also bring the film up to processing temperatures which is handy if the film is really warm or really cool for some reason. Normally neglegible, but I do it. 1 minute presoak at 68F. Developing times normal (for HC110 anyway).

jolefler · Mar 19, 2008

not only the film, but the tank & reels, as well.

CBG · Mar 19, 2008

Never done a presoak. Never had airbells. I always tapped the film hangers to dislodge any air bubbles.

C

jolefler · Mar 19, 2008

Is this the right place.....

to start the thread on pinholes from using an acid stop bath instead of running water?

jim appleyard · Mar 19, 2008

jolefler said:
to start the thread on pinholes from using an acid stop bath instead of running water?

Then we can have the experts debate over what grade of pinhole we are discussing!

Photo Engineer · Mar 19, 2008

Ian Grant said:
That's the other side of the debate no B&W film manufacturer recommends it. This is the 3rd or 4th thread on this subject in as many days
Ian

It began originally, as far as I can find, with a recommendation by Eastman Kodak that goes back to a "How To" book on B&W published in the 40s. I'm sure that with a good search, more references can be found.

Continued references are found in the Jobo instructions and the "Journal of Rotary Processing" published by Jobo.

I personally have done it both ways and found no need to change development time.

PE

fhovie · Mar 19, 2008

St Ansel stated in The Negative that it takes about 20 seconds for a chemistry to penetrate into an emulsion. I always presoak for the following reasons; if the developer does not fill fast enough - it is possible to have very slightly uneven development, the replacing of the water in the emulsion from the presoak by the developer might cause a more even result, it removes the anti halation layer which might influence the chemistry, it helps prevent airbells, and it normalizes the temperature of the film and tank prior to adding developer. None of these are certain and none of these are deal breakers. Kind of like checking your tire pressure before you drive. One time every thousand drives, it might save your bacon - but who does it? I think it is worth it and I all my times are calibrated for a presoak.

Photo Engineer · Mar 19, 2008

Lab measurements say that diffusion to the bottom of a film emulsion is about 15 - 30 seconds depending on thickness and that the solution follows a wetting pattern equal to the flow pattern of the solution.

Wet film hit by developer requires a slightly different diffusion time depending on swell, but follows practically no wetting pattern. In drums it can be worse or better than tank or tray.

You can do an experiment with evenly fogged paper by wetting a piece and sticking it into a slow developer, and side by side immersing a dry sheet and watching them. Since paper goes to completion and Dmax obscures the results, the initial pattern you see is what you actually can get with film.

PE

Nigel · Mar 20, 2008

It doesn't matter if you pre-soak or not. As long as you do it the same way every time, you shouild get predictable results.

Photo Engineer · Mar 20, 2008

Nigel said:
It doesn't matter if you pre-soak or not. As long as you do it the same way every time, you shouild get predictable results.

But with no presoak, as it happens, you do not get predictable results.

I have done this over and over under controlled laboratory conditions. Have you tried the experiment above??

PE

Nigel · Mar 21, 2008

Photo Engineer said:
But with no presoak, as it happens, you do not get predictable results.

I have done this over and over under controlled laboratory conditions. Have you tried the experiment above??

PE

No, I presoak.

George Collier · Mar 21, 2008

Presoaking is also recommended for tube development, primarily for anti-halation backing removal prior to development, especially for stand and semi-stand, I believe. My recollection is 5 minutes for this application.
When I use tubes for 4x5, I presoak with hangers in a separate tank of water same temperature as the dev for 5 min, then load the tubes submerged in a deep tray. It seemed weird at first, but I think it also helps reduce any potential scratching of the film base.

Barry S · Mar 21, 2008

It's easy enough to develop without a presoak and see if you have any problems with airbells or uneven development. If you have no detectable problems, why would you add an extra step? I've never needed a presoak, but I also avoid short development times (<8 minutes), so that may be a key factor. In general, I find longer development times (within reason) increase the robustness of the development process--small variations in timed steps become less critical. I've never seen any information that the anti-halation dyes interfere with development and even if there was some small effect--everyone ends up basing their development on their own methods of exposure, EI rating, developer, development method, etc. (or at least they should). There's a difference between demonstrating an effect or difference, and whether that effect is noticeable on a print or a negative. I think people should do their own testing to see if there's any reason for adding an additional step.

highpeak · Mar 21, 2008

I pre-soak film when I use Pyro developer, it helps get rid of uneven development. For other developers, I don't do pre-soak.

Alex W.

Anscojohn · Mar 21, 2008

I have done it both ways with no discernible difference in down and dirty processing and printing. Does a pre-soak make for more even development, especially in tanks? Perhaps. but I would have to guess the difference is minimal. BTW, I only use small tanks, have never used roller drums--and considering the number of bytes spent on this and other boards trying to figure out roller drum problems--I shall not be using drum processing in the foreseeable future.

A pre-soak, I am told, does require MORE developing time because even though the developer may have a slightly faster induction time, at the same time the developer has to displace the water. Until the water is displaced, the water shall dilute the developer so you are not getting full developer action until that complete displacement takes place, whereas developer action without a pre-soak begins with the induction, for good or ill.

John, Keeping it simple, in Mount Vernon, Virginia USA

Photo Engineer · Mar 21, 2008

Guys;

This has been done to death.

I find that there is no change in development time either way, but uniformity improves and pinholes virtually vanish with a presoak.

I have done experiments under lab conditions to verify the above. Kodak recommends it with film but not with paper. This was their suggestion for all types of process conditions.

Jobo suggests it with all drum processes. Oh, and there was a paper presoak for color paper with the old Kodak drum processors. I have used all types of processes including rack and tank, tray, SS tank with reel, Jobo, Besseler, and the big basket processors up to 16x20. The only place that a presoak was not required was when there was Nitrogen burst agitation as it was so superior to anything else. Even there though it was used to pretemper the basket and paper or film and SS hanger.

It is not recommended for dilute developers which use factors of 1:20, 1:50, 1:100 etc. It should also not be used with 2 part developers.

PE

Ronald Moravec · Mar 21, 2008

Please point out where in written instructions Kodak recommends a presoak for anything other than hand interleaved sheet film.

Photo Engineer · Mar 21, 2008

The 1940s Kodak "How To" book on B&W photographic processing.

They show 3 trays - Developer, water and fix. The developer is presoaked in the water then the water is re-used after development before the fix. Once used for the post development rinse, the water is discarded for the next roll(s). Kodak changed this to include a stop bath after the harder films and papers eliminated the blistering from using a stop. So it was prewet, develop, stop and fix after the hardness was improved.

PE

dpurdy · Mar 21, 2008

Waaaay back before the digital takeover in commercial photography.. the 1980s, I worked in a commercial studio and a Kodak rep was always near by if not lurking around. They gave out info and recommendations and did research on questions all the time. It was one of those guys who told me that Kodak recommends 2 minutes presoak on Tmax films. It was also a rep who told me then that D76 was actually the best developer for Tmax films but they had introduced "Tmax Developer" as a response to photographers who wished for a special new developer. He said it still wasn't better than D76. Of course that is just one Kodak Rep standing around talking and it might be a matter of opinion.

Presoak or not?

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