To pre-wash or not to pre-wash?

[Raghu Kuvempunagar]

When you read this, consider the likelihood that Ilford uses "not recommended" in a very English way:

Actually, Ilford says this: "We do not recommend pre-soaking films prior to development since there is a small chance it can lead to uneven development."

 

[MattKing]

Actually, Ilford says this: "We do not recommend pre-soaking films prior to development since there is a small chance it can lead to uneven development."

But that is only found in relation to continuous rotary processing.

 

[BrianShaw]

Huh?

Here's what is written (with no caveats):

ILFORD FILM FAQ'S

SHOULD I PRE-SOAK MY FILMS?
We do not recommend pre-soaking films prior to development since there is a small chance it can lead to uneven development.

 

[MattKing]

There's no difference, Matt, between what Michael said and what you said that Simon said...

I would agree.
I think though, that people read "not recommended" as being identical to "best not to do". Ilford does use the "best not to do" version in their references to pre-rinse in the context of a continuous rotary agitation procedure.

 

[BrianShaw]

I think though, that people read "not recommended" as being identical to "best not to do".

But that's exactly what it means. Had they written the word 'forbidden' it would mean "never do this"; had they used the word "optional" then it would mean what you want it to mean.

It would help if you would cite (link) to where there is a caveat for rotary processing because the Ilford FAQ, as previously presented, does not have such a caveat.

At this point this discourse seems to be argument for argument's sake, so carry on if you must but without me.

 

[MattKing]

Using the ID-11 datasheet as an example, there is no reference to pre-wash in any section of the development instructions except for with respect to respect to rotary agitation:

The ID-11 datasheet is consistent with any I have read - the only time they reference pre-wash is in the context of rotary tube processors. They don't even reference it with respect to tray processing sheet film.

 

[BrianShaw]

... okay... thanks for that data sheet... so how to you explain the FAQ?

... and I agree... all of the other Ilford processing instructions and guides are silent on pre-wet or pre-wash or pre-rinse. That doesn't lead me to conclude much of anything other than they are not recommending it.

 

[MattKing]

... okay... thanks for that data sheet... so how to you explain the FAQ?

I am not able to do so - it is a relatively new addition, and certainly wasn't there when these discussions (on APUG) involved Simon Galley.
I'm blessed/cursed with having been trained in contract and statutory interpretation. Among many other things, it is a principle of interpretation that if something is referenced in only one section of a document, and refers to that section, it doesn't apply to the rest of the document. Thus my reading of those data sheets.

 

[BrianShaw]

I am not able to do so - it is a relatively new addition, and certainly wasn't there when these discussions (on APUG) involved Simon Galley.
I'm blessed/cursed with having been trained in contract and statutory interpretation. Among many other things, it is a principle of interpretation that if something is referenced in only one section of a document, and refers to that section, it doesn't apply to the rest of the document. Thus my reading of those data sheets.

Me too. In fact, I wrote that kind of stuff too... engineering policy and standards. (and it really is a weird mix of blessing and curse.) I'd state it slightly differently to say the same thing as you said, "if something is referenced in only one section of a document, and refers to that section, it specifically applies to that section."

If the other sections are silent on the topic there are no implications that can be inferred from other sections. Silence, for us, sometimes resulted in contractual conflict because differing interpretations of what that silence implies. But in the end... silence is not directive nor is it implicative... it's either intentional or an error/omission and until something specific is written doesn't say anything. You know that!

Simon didn't say much either that is definitive or particularly authoritative, other than to support Michael's posture that If you pre-soak and don't have any uniformity issues, or don't pre-soak and don't have any uniformity issues, there is no reason to alter your process.

So now... which one of us has the bigger dick, or ego? LOL

 

[MattKing]

Simon didn't say much either that is definitive or particularly authoritative, other than to support Michael's posture that If you pre-soak and don't have any uniformity issues, or don't pre-soak and don't have any uniformity issues, there is no reason to alter your process.

For clarity, this is what I have always been saying.
What I have been responding to though are the relatively frequent occurrences of people posting something akin to "do not pre-rinse, because Ilford says it is not recommended".
I've never thought that was what Ilford was saying, until you referred me to that relatively new FAQ.

 

[cliveh]

I would imagine that pre-washing causes no problems, but is it necessary? You will still get the same result by reciting a religious mantra to the tank as you process, or not.

 

[BrianShaw]

I would imagine that pre-washing causes no problems, but is it necessary? You will still get the same result by reciting a religious mantra to the tank as you process, or not.

It depends on who you ask. Ilford... it could cause problems with one kind of processing AND is not generally recommended because there is a small chance of problems overall; St Ansel ... always pre-soak "to ensure consistent development". The only thing consistent in this discussion is the inconsistent recommendation on whether it is worthwhile or not.

EDIT: Adorama says it is "crucial" to pre-wash: https://www.adorama.com/alc/faq-how-to-develop-film/

 

[alanrockwood]

And with all of this talk about uneven development with prewash or uneven development without prewash, I don't think anyone in this discussion has presented any measurements to demonstrate whether one method is better than the other with regard to evenness of development, nor have any scientific papers on the topic been cited.

If it were very important one would think that sometime in the 150+ years of photography someone would have done the necessary experiments to show one way or the other which method produces more even development. It wouldn't be hard, and a preliminary set of experiments should take no more than a few days. I'm not going to do the experiments because I have better things to do with my time, and the chip in my phototherm processor does not include prewash in the program options for black and white film development, so for me the whole question is moot, except perhaps from a scientific point of view.

One thing is for sure though. Prewash does extend the time required to achieve a given level of development, and in some cases this might be a desirable result... or not depending on the situation.

 

[Raghu Kuvempunagar]

One thing is for sure though. Prewash does extend the time required to achieve a given level of development,

Is this dependent on the pH of water used for pre-wet?

 

[Vaughn]

...One thing is for sure though. Prewash does extend the time required to achieve a given level of development, and in some cases this might be a desirable result... or not depending on the situation.

If one is not working in a consistent manner, than one should not be worrying about slight differences in time caused by pre-wetting. And if one is working in a consistent manner, then the slight change in development time due to pre-wetting has been taken into consideration in one's testing.

So pre-wetting makes no significant shift in one's developing time that one needs to be concerned about..

 

[removedacct2]

Call me stupid or mad (or a crazy European), but I prewash for 10 min ...The anti halo layer colour coming out when pouring the pre wash water is convincing me that I am doing good.

same here. I have a plastic jar filled with water inside the bath. Some time after bath has reached processing temperature, I pour the content of the jar in the tank, lock it and dip it in the bath. Do something else while it soaks for 10 or 15 mn before I start processing. I like to see the halo layer get washed away when dumping the soaking water. My routine is uniform, BW, C-41, and soaking/washing is anyway mandatory in order to remove remjet when I process motion film, it's also quite important when I started recently doing BW+C41 dias processing instead of E6. So no matter what, first soaking.

 

[alanrockwood]

If one is not working in a consistent manner, than one should not be worrying about slight differences in time caused by pre-wetting. And if one is working in a consistent manner, then the slight change in development time due to pre-wetting has been taken into consideration in one's testing.

So pre-wetting makes no significant shift in one's developing time that one needs to be concerned about..

I probably wasn't clear enough in my post. I am not saying that prewash makes the development time inconsistent. It just extends development time required to reach a certain density. If the prewash time is consistent (and presumably conforms to the the recommended 5+ recommended by some people) then it should not make the overall process less consistent.

 

[mshchem]

I wonder if ANY commercial lab pre-wets film. It's certainly not done any any sort of minilab, nor dip and dunk machines. When I presoak It's to make sure I'm at the same temperature everytime. In commercial labs they don't need to worry about the tank effecting the solution temp.

 

[Vaughn]

I would imagine that pre-washing causes no problems, but is it necessary? You will still get the same result by reciting a religious mantra to the tank as you process, or not.

Do religious mantras warm my drum and film above room temperature? Wow! Sign me up for that religion!
I think in common English usage and most likely technical writing, too, "not recommended" is not the same as 'don't ever do it'.

 

[mshchem]

Do religious mantras warm my drum and film above room temperature? Wow! Sign me up for that religion!
I think in common English usage and most likely technical writing, too, "not recommended" is not the same as 'don't ever do it'.

I used to put my Paterson tank under my sweater to warm it up. Didn't chant, or say anything special, .....but I could

 

[mshchem]

I remember in high school my friend somehow got the funds to buy a 1967 E type Jaguar. The manual that came with the car, in British fashion, recommended not operating the car in excess of 120mph for extended periods.

 

[alanrockwood]

...E type Jaguar...

The most beautiful car ever made.

 

[Murray Kelly]

Do we have any polite comments about prewetting and 2-baths? My thought is to reduce the accumulation of dyes and iodides in the first bath.
Naturally the first bath would have to be extended abd vigourous.

 

[foc]

I wonder if ANY commercial lab pre-wets film. It's certainly not done any any sort of minilab, nor dip and dunk machines.

I have never seen a commercial film processing machine that pre-wets the film. In a commercial lab, time is money, so why pre-wet when it is not necessary.
Maybe where a lab uses a non-automated process, rotary tank, small tank etc, they may see the need for a pre-wet, but in all my years processing commercially and talking and visiting other labs, big and small, professional and amateur, I never saw a pre-wet/pre-wash used.

As an analogy, it remind me of the argument about cooking pasta. One says to use a big pot with plenty of water. The other says that a drop of oil into the water in the pot will stop the pasta from sticking.

Discuss.................

 

[Don_ih]

Has anybody bothered to test if there is any difference? That is, shoot a strip of film with every exposure the same, cut the strip in half, develop one with prewetting and the other without? It would really only take half an hour to do.