Pre soak/pre wash why or why not?

[MattKing]

The biggest reason that I pre-wash/pre-soak film is that I have done so for years, and if I stopped doing it, I would probably have to make some slight adjustments things that I currently don't need to adjust.
It is currently incorporated into my workflow.
I expect that I could achieve the same results without it - after adjustments - but I don't see the need to do so.

 

[Vetus]

I often use BTZS tubes, and a prewash is a welcome step to eliminate AH layer on some films like TMY-2.

Does the anti halation dye have any affect on the developing process apart from adding colour to the developer, stop and fix? I don't know, but it would be reasonable to think that it doesn't do anything significant or film manufacturers would not use it.

 

[BradS]

Does the anti halation dye have any affect on the developing process apart from adding colour to the developer, stop and fix? I don't know, but it would be reasonable to think that it doesn't do anything significant or film manufacturers would not use it.

No. the dyes have no significant effect on the dev/stop/fix. In fact, if the developer has sufficient sulfite concentration (eg D-76, D-23, etc), the dyes do not even discolor the developer but the fixer may still show a slight tint and possibly the first wash cycle too.

 

[Andrew O'Neill]

Does the anti halation dye have any affect on the developing process apart from adding colour to the developer, stop and fix? I don't know, but it would be reasonable to think that it doesn't do anything significant or film manufacturers would not use it.

None that I can see. The reason why I pre-wash TMY-2 before sticking it in the tube is because of the blue AH layer, that does not come out so easily.

 

[BrianShaw]

None that I can see. The reason why I pre-wash TMY-2 before sticking it in the tube is because of the blue AH layer, that does not come out so easily.

Is that a function of tube processsing versus other processing methods?

 

[Doremus Scudder]

Off-topic, but I think many of you are confusing anti-halation dye and sensitizing dyes.

The former keep absorb light after it has passed through the emulsion once to keep it from bouncing and going back through again, causing halos (hence anti-halation). These are water-soluble and wash out easily.

Sensitizing dyes are there to make the silver halides in the film sensitive to different colors than blue. Panchromatic films would be impossible without them. These are the stubborn ones in many films that end up tinting the emulsion pink or blue and need extra fixing and/or washing to get rid of.

Back on-topic: I presoak sheet film because I tray develop and they would stick together otherwise. I don't presoak roll films that I develop on reels. Development time is essentially the same with both as far as I can see.

Best,

Doremus

 

[Andrew O'Neill]

Is that a function of tube processsing versus other processing methods?

Only when I use BTZS tubes. Not an issue with tray development... Developer, cannot get in behind where the film makes tight contact with the tube.

 

[Augustus Caesar]

Despite claims to the contrary, I have never had any issues with air bells when using pre-wetting. On the other hand, I have had them when I did not pre-wet. Not often, but more than zero. With pre-wetting, zero. Case closed. I cannot imagine what harm it would do, and the benefits are demonstrable.

I use Paterson tanks and hand inversion agitation, twice, once per minute.

 

[Maris]

I always do a thorough pre-wash but it's not for the benefit of the film or notions of image quality. I pre-wash to preserve my Replenished Xtol developer from accumulating antihalation dye, spectral sensitising dye. acutance enhancing, dye, and possibly speed trimming dye. A replenished developer loaded with dye becomes a murky mess of unknown (unknowable?) composition that prompts discard. By keeping dyes out of my Xtol it stays clear-ish and can do many many films without an alarming change of appearance.

 

[Paul Howell]

Did Kodak recommend pre wash when using replenished Xtol?

 

[Vaughn]

...
The companies who make film must have scientifically tested if pre soaking film has any advantages for both roll film and sheet film.

I have not read a film manufacturer warn against a pre-soak...just not recommending one. By not recommending one, the film companies have one less variable to have to deal with consumer questions/complaints about...

I presoak because like looking at the color of that first rinse water, it gets me in the routine before messing with the developer, and it gives me something to do while I mix up the developer and get it to temperature. Oh, and the highly experienced manufacturer of my equipment recommends a presoak, so that is an influence on my decision..

 

[MattKing]

Did Kodak recommend pre wash when using replenished Xtol?

Most of the Kodak advice respecting replenishment is clearly oriented toward large tank dip-and-dunk or continuous roller processing lines, so it would be surprising to see language that relates to a pre-soak.
The single exception relates to the times provided for seasoned developer in rotary processing tubes.
FWIW, the Kodak recommendations for small tanks recommend adding the film to tanks that are already filled with developer, rather than adding developer to a tank filled with film. Perhaps using a pre-soak helps the system perform in the same way that it performs when you fill the tank with developer first, and then add the film.
Or perhaps not.
Those of us who use replenished X-Tol with small development tanks and small numbers of rolls are basically adapting the Kodak advice to work in different circumstances. A pre-soak may help with that adaptation.
Or perhaps not.
In any event, the Kodak advice is silent on the issue.

 

[RalphLambrecht]

Ilford recommend that no pre soak is necessary for their films. I have read on this forum, some people like to pre soak their film, why?

We've done this a few times, but here again are some of the pros and cons of prewashing film:
Pro:
• gets film and processing equipment to temperature
Cons:
• washes some but not all of the antihalation layer off, leading to spottiness
• water penetrates the emulsion, leading to prolonged development times and possibly uneven development
• extra processing step and thereby waste of time
• if done sloppy, it can create water spots

Take your pick; you'll be the judge!
and now be prepared to listen to all the folks who have done either for 30 years and never have a problem.

 

[Vetus]

I have read with interest all the replies and as much as I want to that is posted on the web. Thank you everyone for your insights. I have decided that because I use roll film and paterson tanks with one shot developers I will not be pre soaking. If I was tray developing sheet film I can see a good reason to pre wet the film (not soak it) to prevent the sheets sticking together. If I was using rotary proccessing with a jobo lift I would give a 90" maximum rinse. My reasoning is that the developer may work on the surface of the film more evenly as it is poured in, especially when using short development times. I would not use a pre soak with a rotary jobo that has no lift because the tank is filled quickly and then attached to the processor. Replenishing developer with dip and dunk processing? Do the dyes degrade the developer or do they just look murky ? I think what Maris said was reasonable, I would probably do a short pre soak to maintain and keep my chemicals as "clean" as possible.
My next thing to ponder is, why do some people advocate a pre soak when using pyro developers, especially when stand developing is employed, is it another "to do" because someone once said it was a good idea? I can't get my head around pouring a very diluted developer onto an emulsion already swelled and soaked in water.

 

[Mr Bill]

I pre-wash to preserve my Replenished Xtol developer from accumulating antihalation dye, spectral sensitising dye. acutance enhancing, dye, and possibly speed trimming dye. A replenished developer loaded with dye becomes a murky mess of unknown (unknowable?) composition that prompts discard. By keeping dyes out of my Xtol it stays clear-ish and can do many many films without an alarming change of appearance.

Hi, fwiw I spent a lot of years as a large-lab QC guy, my department overseeing the "process control," results of chem mix, and loads of troubleshooting. When I started this as a near wet-behind-the-ears kid it was with the predecessors (C-22 and Ekt 2/3) of today's C-41 and RA-4. Also a handful of other processes, b&w, all replenished. None of these ever used a pre-wash, and never had any obvious problems related to lack of same. But... I have never dealt with Xtol other than my personal use.

There IS one significant difference in that every one of these machines used filtered recirculation systems (where said filters collected considerable "sludge"). Which I sorta presume the small-scale home users are most likely not using.

FWIW we pulled chemical samples, about 40 to 50 per day, from (all) of our processing machines for basic screening (pH and specific gravity). All of the color developers took on a color unique to the specific materials being processed (we kept them segregated on different processors). But all developers were "clear;" no obvious cloudiness. And, as I said, never any obvious problem related to build-up of whatever byproducts.

With respect to (non-development) byproducts building up in a developer, the concentration is ultimately limited by dilution due to the replenisher. Occasionally people on this forum will say that, "oh, if you don't periodically discard some volume of developer then the concentration of byproducts will just keep increasing." But this is not true. These concentrations are controlled by the amount_released per the volume of replenisher added. (Ignoring evaporation.) Whether developer is discarded or not is essentially irrelevant to this although, for practical purposes, some has to be discarded sooner or later.

FWIW the lowest replenishment rate system for a C-41 developer is Kodak LORR replenisher, which runs at a rate of approximately 25 to 30 ml/roll (135-36) as I recall. In other words all byproducts released (into developer) from a single roll of film will, loosely speaking, be contained in that 25-30 ml of added replenisher volume. (The equilibrium concentration will be: total byproduct divided by volume added.) Now, my understanding is that replenished Xtol gets replenished at something like 2 or 3 times that of the LORR. Which means that, all else being equal, replenished Xtol should only reach something on the order of 1/2 to 1/3 of the (non-development) released-component concentration that a C-41 developer would have. Which in my C-41 experience is never a problem. So I would tend to suspect Xtol would likely not have a problem either. But I don't have any first-hand knowledge of this. And I am glossing over some of the details. So this is just some food for thought.

 

[RalphLambrecht]

Does the anti halation dye have any affect on the developing process apart from adding colour to the developer, stop and fix? I don't know, but it would be reasonable to think that it doesn't do anything significant or film manufacturers would not use it.

after exposure, the anti-halation layer no longer has any function. Nevertheless, it's best to have it all gone (washed out) to prevent spots and patches during enlargement. That said, a sufficiently long wash will also take care of that.

 

[Vetus]

When replenishing developer on a small scale.To filter out processing bi products you could pour the used developer through a coffee filter before adding it back into your stock .

 

[Mr Bill]

Replenishing developer with dip and dunk processing? Do the dyes degrade the developer or do they just look murky ?

In my non-Xtol experience, neither. Not a problem. But... as I mentioned these processors used substantial circulation pumps and filters. And... these chemical systems were designed for machine processing and replenishment. If there were shortcomings the Kodak of those days would solve the problems - no doubt about it.

With Xtol I dunno for sure how it behaves. People who actually use it could best answer the question. But I'm pretty doubtful that sensitising dyes or whatever would have any sensitometric effect.

 

[Fatih Ayoglu]

I perform prewash based on the film in the tank.
If I develop Foma, I do prewash because I like that green first water in the tank, the best 2 green things from Czechia, Absinthe and FOma prewash water
If the films are Ilford or Kodak, I do not prewash
If it is C41, I do prewash to warm up the tank, the reels and the films inside.

 

[brbo]

Most of the Kodak advice respecting replenishment is clearly oriented toward large tank dip-and-dunk or continuous roller processing lines, so it would be surprising to see language that relates to a pre-soak.

Kodak's Z131 document (C-41) explicitly mentions, in bold, not to pre-soak with rotary-tube processing.

I've found out that pre-soak and using stop bath (which is also not a standard C-41 step) helps me with uneven development of large format C-41 film. I feel like there is little point in sticking religiously to the instructions when they clearly don't work (for me)...

 

[Vaughn]

... I can't get my head around pouring a very diluted developer onto an emulsion already swelled and soaked in water.

What is the difference, wet or dry? A dry emulsion brings in water and the chemicals in it, and the developing chemicals initially brought in are quickly exhausted. The rest of the development is done by developing agents slowly entering or having contact with, the emulsion. Starting with a wetted emulsion is no different except for that brief instant when the dry gets wet. The difference in the amt of development between wet and dry is not significant.

 

[DREW WILEY]

I briefly presoak 100% of the time, including with all Ilford films. You know the saying - if it ain't broke, don't try to fix it; and it certainly works for me. I began with sheet films, which are difficult to quickly slip in due order into a tray and shuffle without sticking to one another if a pre-soak isn't used. There is much more risk of uneven development streaks and so forth without it. And for sake of consistency, I transferred the same habit to roll film tank development when I eventually got into that too.

Have I tested for the alternative - no pre-soak? - yep. And the unsatisfactory end results are just as "scientific" as any other factor. Others can make their own determination of what works best for them.

I always do a presoak step when developing color paper in drums too. It does two important things : First, it helps temper the interior of the drum to the correct processing temperature; Second, it helps the developer spread quickly and evenly. Otherwise, streaks or splotching are a distinct risk. Drums are more practical for my own color printing workflow, even with big prints, than roller-transport machines.

I don't do my own color film development. That's pretty much a standardized thing, so I simply let the labs do my E6 and C41 work in their dip n dunk machines.

 

[Sirius Glass]

Without intent to be rude, but this is both a well-discussed and contraversial topic where discussions rarely end well. Have you tried the search facility with the terms "presoak" and "pre-soak"? Either or both will yeield the prior discussions that will help you with your question of "why". Another easy option would be to peruse Ansel Adam's The Negative, where the topic is well discussed including why he advocated pre-soak of emulsions back in the good old days.

In this era, I use Ilford B&W film and their recommended processing practices. The simple answer from my experience is that pre-soak simply doesn't add value. Others claim that it might increase the even-ness that the chemistry is absorbed by the film and others claim that some films benefit from having the anti-halation layer washed off by such a process.

If you have read forum posts about pre-soaking, I'm sure that you have seen this information already, though.

As Brian discusses, this is a topic that reaches religious proportions, much like which end of an egg to open in Gulliver's Travels. I pre-soak all films except Kodak Tri-X 400 when using replenished XTOL in the JOBO processor following advice given in a book on the Jobo processor.

 

[Vetus]

What is the difference, wet or dry? A dry emulsion brings in water and the chemicals in it, and the developing chemicals initially brought in are quickly exhausted. The rest of the development is done by developing agents slowly entering or having contact with, the emulsion. Starting with a wetted emulsion is no different except for that brief instant when the dry gets wet. The difference in the amt of development between wet and dry is not significant.

Thank you for the explanation.

 

[Vaughn]

Thank you for the explanation.

You are welcome. As the old joke goes...another country heard from.

A thought added: I suppose the most active developing happens at the beginning -- until shadow areas are fully developed and the developer only has mid-tones and highlights to work on...and so on. Which is probably why all developing methods stress have good agitation at the beginning to quickly replace exhausted chemicals in contact with the emulsion.