Pre-soak

[cliveh]

I sometimes read on APUG posts about pre-soaking films with water prior to development. I have never ever done this, can someone explain what am I missing?

 

[cjbecker]

It is something that i always do. It promotes more even development. At lease that is what I have seen. Plus i don't like all the extra in with my chemicals.

 

[Photo Engineer]

OMG what a nest of worms here. Do you enjoy this?

Prewetting was taught by EK for film processing back in the 40s and earlier. They never countered it. It was advised so that air bubbles would be removed by the pre-wet and so that the film was fully and evenly wetted when you went into the developer. So, you got better uniformity and no spots from air bells.

So, there were two purported advantages to this.

Then, with higher temperature processes, it was found that the drums were more evenly and fully warmed to the correct process temperature by a prewet. So, we now saw 3 reasons.

Some argue that this is BS and others consider it gospel.

I have used a prewet for all color film and most all B&W film done in tanks. Using 4x5 stainless racks, the agitation is more efficient than with rolls and drums and so I have not used it, but then I also often had nitrogen burst backup on those occasions.

I am beginning to believe that this effect depends on operator competence and many other factors such as mix water (tap vs DW) and on the developer and development times. Kodak mentions potential problems with unevenness with short development times.

So, I say "Use what works". This is the best answer with such a controversial issue.

PE

 

[cliveh]

OMG what a nest of worms here. Do you enjoy this?

Prewetting was taught by EK for film processing back in the 40s and earlier. They never countered it. It was advised so that air bubbles would be removed by the pre-wet and so that the film was fully and evenly wetted when you went into the developer. So, you got better uniformity and no spots from air bells.

So, there were two purported advantages to this.

Then, with higher temperature processes, it was found that the drums were more evenly and fully warmed to the correct process temperature by a prewet. So, we now saw 3 reasons.

Some argue that this is BS and others consider it gospel.

I have used a prewet for all color film and most all B&W film done in tanks. Using 4x5 stainless racks, the agitation is more efficient than with rolls and drums and so I have not used it, but then I also often had nitrogen burst backup on those occasions.

I am beginning to believe that this effect depends on operator competence and many other factors such as mix water (tap vs DW) and on the developer and development times. Kodak mentions potential problems with unevenness with short development times.

So, I say "Use what works". This is the best answer with such a controversial issue.

PE

I have not processed much colour film, so this could be a good thing to do. However, for black & white I knock the tank at the start of development, which hopefully dislodges any air bubbles.

 

[Rick A]

I always use a pre soak when developing, for all the reasond posted by PE. It gives the added advantage of removing any anti-halation dye prior to developing and helps keep my fixer clean, except with T-Max, no matter what it turns my fixer purple.

 

[cliveh]

I always use a pre soak when developing, for all the reasond posted by PE. It gives the added advantage of removing any anti-halation dye prior to developing and helps keep my fixer clean, except with T-Max, no matter what it turns my fixer purple.

Is water a solvent for anti-halation dye and how does this help after the picture is taken? How does this keep the fixer clean?

 

[Rick A]

Most of the films I develope are European and Chinese and have anti halation dyes that are water soluable and are removed with the presoak. Since most of the dye is removed prior to developing, there is almost nothing left to dissolve in the later stages of the process. I must add, I use my stop bath diluted to 50% of recommended and use a water rinse between stop and fixing. I've found I get longer life from my fixer this way, and twice as much stop bath. I am a cheap-skate, what can I say.

 

[cliveh]

Most of the films I develope are European and Chinese and have anti halation dyes that are water soluable and are removed with the presoak. Since most of the dye is removed prior to developing, there is almost nothing left to dissolve in the later stages of the process. I must add, I usr my stop bath diluted to 50% of recommended and use a water rinse between stop and fixing. I've found I get longer life from my fixer this way, and twice as much stop bath. I am a cheap-skate, what can I say.

But how does removing the anti halation dye help after the picture is taken?

 

[Rick A]

The dye is designed to be removed during development so the negative will allow light to pass through for printing.

 

[cliveh]

The dye is designed to be removed during development so the negative will allow light to pass through for printing.

If the dye is designed to be removed during development, why pre-soak?

 

[clayne]

I just do it so I can play with all of the dyes upon pouring the pre-soak out.

 

[Rick A]

Reread PE's post (post #3).

 

[Smudger]

There is another reason to pre-soak : and it's probably just aesthetic : Rollei and Adox films have a ghastly green or blue anti-halation dye , which would turn my replenished Xtol an indescribable hue if I didn't presoak.These manufacturers recommend presoak,for whatever reason.
Since I like to keep an eye on the physical condition of the developer,which the dye would obscure.
With Ilford,Kodak or Fuji films I don't bother.

Could PE comment on whether A/H dyes have ANY effect on the chemistry ?

 

[removed account4]

hi cliveh

the thing about pre soaking is that sometimes it is useful
and allows the gelatin to swell before putting the film in developer
just the same, it sometimes it adds trouble and causes streaking and uneven development.
so, if you don't do it, and you haven't encountered any trouble with your development methods
i wouldn't worry about it ...

the AH dyes are coated on the film so there isn't blowback-flare when making exposures
it is the same reasons why the pressure plate or back of a film holder against the film or inside the camera
is black, to reduce light going through the film and back onto it after bouncing around the inside of the camera.

if you want to have some fun, save your pre soak water, and your developer.
pour all the blue black dye in your developer beaker .. and watch as it vanishes ..
it seems that some developer are designed to absorb the AH dye and not loose potency ...
so, if you don't pre soak, the dye is absorbed into your developer and probably not carried into your stop or fixer ( without you realizing it).

i always pre soak out of habit, but when i forget, or just don't do it, i don't worry about it ...

have fun !
john

 

[chimneyfinder]

For the first 20 years of my film processing, some for museum archiving, I never pre-soaked and never had any problems associated with not doing it. Now I pre-soak when using Presycol developer to get the film to @24C, and because it is recommended for semi stand development to promote more even initial development, but I'm not sure how substantiated this is (there are counter arguments I believe). Again, no problems doing this, so my input is to do what you think best. On a firmer basis, it is possibly most useful in promoting consistent developer temperature: as a 20C. solution poured onto a 16C. film tank, for example, would affect standard development time. Hence, if your equipment is cold and you don't pre-soak it is probably a godd idea to take the developer temperature after a minute or two in the tank and possibly adjust development time. If you are happy with your results, fine, but there is usually room for a little fine tuning that may have happy consequences.
Regards, Mark Walker.

 

[eddie]

I'm not sure if it matters either way, but I've been doing it for over 30 years, so I see no reason to stop now. I started doing it before I had a Jobo, and have continued my routine, with the Jobo. I get nice, even negatives from my workflow. Others get nice, even development without a pre-soak.
John- I've only seen problems with streaking and uneven development if the pre-soak is too short. I used 2-3 minutes prior to the Jobo, and 5 minutes with it.

 

[Photo Engineer]

The dyes are not supposed to hurt development and are designed to wash out in the process. The problem is that the developer, stop and fix can become colored from these dyes, and if you run a mix of films and replenish, then every solution can become murky brown.

I suggest that you use what works. However, a simple test for you. Take a sheet of clean white absorbent paper of about 90 - 100 # weight and just submerge it into water. Watch how uniform the wetting is and whether bubbles rise from the paper. Now, take a piece of film and dip it into a beaker of running tap water and watch the surface of the film for bubbles and wetting. These two simple tests will show you the wetting properties of porous materials, the effect of entrained air, and the effect of air in ordinary tap water. BTDT!

Jobo sells a little device to break up small bubbles and cause them to rise. This improves washing. So, watch your wash water too. You can see your film covered with bubbles! Each bubble is preventing efficient washing! Same thing, different step of the process.

PE

 

[Leigh B]

I have pre-soaked b&w film since I started processing over 50 years ago, except with developers for which it is not recommended.

One such developer is Diafine. They specifically say not to presoak because it will interfere with take-up of Part A into the emulsion.

- Leigh

 

[Photo Engineer]

Yes, you should never pre-soak with a divided developer.

PE

 

[cliveh]

Interesting comments. I suppose as I use D76 1:1 and discard after use, it has not been a problem.

 

[Doremus Scudder]

I tray develop sheet film. Without a pre-soak, the sheets will often adhere to each other and take a looooong time to soak apart. I don't need that happening in the developer! It happens on occasion in the pre-soak if I don't let the previous sheet soak long enough, but then I can take the time needed to separate them without worrying about uneven development. I don't see this reason above, so let's add it to the great reasons PE listed.

I don't see how pre-soaking film before development can cause streaking and unevenness as someone above mentioned. Just the opposite would be my impression. Nor do I see many viable arguments against using a pre-soak that have been substantiated. Of course, with divided developers, where one wants the emulsion to take up developing agents as rapidly and fully as possible, a pre-soak makes no sense, especially when you remember that the vast majority of the actual development only takes place in the B-solution.

I use staining developers, which are rather finicky when it comes to unevenness; I need all the help I can get to have the developer infuse into the emulsion at an even rate. I believe that pre-soaking, and transferring a completely saturated emulsion into the developer aids this, since the exchange of water and developer happens more slowly and evenly and the inevitable unevenness of immersion is therefore minimized.

Best,

Doremus

www.DoremusScudder.com

 

[Athiril]

I pre-soak all colour film. And most B&W film, some specifically says not to (like some Rollei films such as ATP), I'll pre-soak all films intended for stand development and short development times (gives me a bit more buffer zone in time to get the lid on and starting my initial agitation).

 

[RalphLambrecht]

I sometimes read on APUG posts about pre-soaking films with water prior to development. I have never ever done this, can someone explain what am I missing?

noyhing ¡presoaking is n extra step with little or no benefit and comes with it's on set of problems. i wouldn' consider it unless you sre dealing with extremely short developib times <4 minutes.

 

[Ian Grant]

Like Ralph I think a pre-soak is an unnecessary step for most processing, it is beneficial when processing colour materials at well above room level temperatures (38ºC) in bringing the tank, spiral and film up to temperature.

I've never seen a pre-soak recommended by manufacturers for B&W films, and with some developers that use the tanning action of certain developing agents a pre-soak is best avoided. Prescysol which is a Pyrocat clone would fall into that category.

Ian

 

[Photo Engineer]

Kodak recommended a presoak for Pan Matrix Film before entering the tanning developer.

Sheets of film sticking together would certainly be a real problem. I don't tray develop sheet film, I use film hangers in hard rubber tanks. Thus my sheets are separated by the metal hangers.

PE