Topic: Do you presoak?

[Pete_R]

I was looking up a dev time on the Massive Dev Chart and it mentioned a presoak. This was for Fomapan 100. I never presoak. Looking around the net seems various people extol the benefits of it but they don't all agree on what those benefits are. So does anyone here do it and, if so, why?

[Kai-san]

I have made it a habit to presoak all films. Regarding Fomapan, if you presoak you will see that it gives off a stark yellow or green colour. I forget which Fomapan gives off which colour. I do not know what that green/yellow stuff is, possibly something that's added for easier mechanical handling of the film. There are probably someone on this forum who knows. Now for those who re-use their developer it will naturally become green or yellow, what other effects it could have I do not know. It's the same with Kodak T-Max films in 35mm format, it gives off a pink colour. If you do not presoak the T-Max, the base of the film will be pink when you are finished. Other benefits could be to prevent any bubbles sticking to the film in processing.
My rationale for presoaking is basically common sense; it might be beneficial and it surely will not do any damage.

[Francois]

The color that comes off is the anti halation layer.
Pre soaking has a few benefits. First, it swells up the gelatin so that developer gets absorbed more evenly.
Second is that it wets the film so that you can tap off the air bubbles.
And on color film it also gets the emulsion up to temperature ready for development.

I personally don't always do a pre soak. I usually use it when development times are really short. But I almost always give the film a short water bath just to get the bubbles and ah layer off. Just about a minute continually agitating while banging the tank on the palm of my hand. I don't even time it. If when I pour it out it has some color, I fill it back up and go for another round.

[Pete_R]

Well the Fomapan 100 certainly produces a bright green colour. But I only ever use one-shot developers and I don't use a stop, just a quick rinse that gets dumped, and very little of that colour gets carried over to the fix and a slightly green fix doesn't hurt as far as I know. Apparently, from what I read, Foma used to recommend it for Fomapan but I couldn't see anything on the instructions so didn't bother. If it's just the antihalation colour that's the issue I'm not bothered. I used to use Rollei RPX25 which turns the developer dark red but never had a problem not using a presoak. Someone mentioned that presoaking dilutes the developer because the water absorbed by the emulsion means it doesn't absorb the developer as much. So maybe there's pros and cons to it.

Fomapan 100 in Ilfosol 3. Yashica D modified with Yashinon (Tessar) lenses. No presoak :-)

[astrobeck]

99% of the time I do not presoak.
For color as Francois mentioned, it is necessary to get the emulsion up to temp and that's only a minute.
Otherwise I just go without doing it.

I never thought about a presoak diluting the developer...it makes logical sense it could happen...but I don't know the reality of it.

I'm Following this. I'd like to know.

[Bryan]

I always pre-soak, especially since I often develop with beer, don't want bubbles.  I usually try to bang off bubbles during the pre-soak and I never have problems with bubbles.  For non-beer developers I've heard arguments both ways so I don't know if it's really necessary. 

I have had problems with the anti halation layer when developing two different types of film at the same time.  It came off one film and deposited a stain on the other film.  The stain was not even across the film because it sat still for a short period of time during the pre soak.  I have noticed that the anti halation is heavier than water so it tends to settle to the bottom.  That's how it left an uneven stain.  You can see this when you pre soak and let the film sit still for a few minutes.  When you first start pouring it out the color is lighter at first getting darker as you get to the bottom. 

[Pete_R]

I always pre-soak, especially since I often develop with beer, don't want bubbles.  I usually try to bang off bubbles during the pre-soak and I never have problems with bubbles.

I always bang the bottom of the tank after the initial agitation and I don't think I've ever had problems with bubbles.

I have had problems with the anti halation layer when developing two different types of film at the same time.  It came off one film and deposited a stain on the other film. 

That's a really valid point for me as I do mix films in the same tank sometimes.

[Kai-san]

I did a search on this topic and found an FAQ page on Ilford Photo about presoak of their films, this is what they say: "We do not recommend pre-soaking films prior to development since there is a small chance it can lead to uneven development".
When they say "a small chance" I reckon that it is very unlikely to happen. But in general I suppose we should pay heed to what the film makers say. I do not use much Ilford film so I cannot remember whether there is a stain problem with any of those.

[Francois]

I was thinking about the developer dilution thing.
I tried finding the thickness of the actual gelatin emulsion layer (no luck there), but considering how thin it is, it's very unlikely that it would contain enough water to seriously dilute the chemicals.
What it does do is slowly let the developer penetrate the emulsion (concentration goes up a bit slower). So, you should get a slightly lower density when measuring with a densitometer.
Will that affect things in real life? Probably not since my eye is far from being this precise. I know Ansel would frown upon my reasoning, but come on...

I'm surprised that Ilford says it can result to uneven development. The only thing I can see that would cause that is if the gelatin hasn't had time to completely swell-up on the film; uneven emulsion will always result in uneven development. But given enough time, it really shouldn't be a problem.

[Pete_R]

I was thinking about the developer dilution thing.
I tried finding the thickness of the actual gelatin emulsion layer (no luck there), but considering how thin it is, it's very unlikely that it would contain enough water to seriously dilute the chemicals.

That's what I originally thought but I think it's the fact the emulsion is saturated with water which dilutes the developer in or near the emulsion that makes the difference. Probably less of an issue with frequent agitation but maybe more so with stand development.

[Jeff Warden]

I did for a while but could see no difference in the negatives, so I stopped.

[Francois]

I was thinking about the developer dilution thing.
I tried finding the thickness of the actual gelatin emulsion layer (no luck there), but considering how thin it is, it's very unlikely that it would contain enough water to seriously dilute the chemicals.

That's what I originally thought but I think it's the fact the emulsion is saturated with water which dilutes the developer in or near the emulsion that makes the difference. Probably less of an issue with frequent agitation but maybe more so with stand development.

Probably as the chemistry will migrate more slowly and we're already dealing with very dilute solutions.

I think sometimes that this technique of pre soaking was more useful with the older films that were less well made than today's modern emulsions.

[MrclSchprs]

I do presoak as I have standardised all my development at 25 degrees Celsius and presoaking helps to warm up the tank, reel and film before the developer gets in. I've done a visual comparison and I do see a clear difference. Especially during the winter months.

[astrobeck]

in the winter I mix my developer a couple of degrees warmer just so the initial "shock" of going in a cold tank evens out the temperature drop or perhaps compensates for it....not too sure this even helps, but it's my habit.
For black and white I use caffenol always, so I'm not on the razors edge of developing finesse. 

Color though, is another ball game.

[Moto-uno]

  Presoak was certainly the norm in the 70's , but I haven't found any B&W film that I use ever recommend presoaking now .
  Peter

[Sandeha Lynch]

Do any films expressly discourage it?

I started pre-soaking, and have always done it since, when I read through the instructions on my Jobo tank. At the time I thought it might be something to do with flow patterns given the tank's shape. But I've never thought about it since.

[MrclSchprs]

  Presoak was certainly the norm in the 70's , but I haven't found any B&W film that I use ever recommend presoaking now .
  Peter

Bergger recommends pre-soaking their Pancro 400 film, especially if you use their PMK developer.

https://bergger.com/en/index.php?controller=attachment&id_attachment=4

[Francois]

I'm starting to wonder if the pre-soaking recommendations aren't related to how hardened the emulsion is?