Presoaking film and development time

[DREW WILEY]

I was interrupted by dinner. But I was going to add that the postulate that a very long dilute development effectively preempts the need for a pre-rinse might seem to make sense, but we never really know unless all the pertinent variables have been objectively tested an compared. Incidental findings don't cut it for me; but I'm in no mood or need to make those kind of tests myself. I've certainly done more than my fair share of film testing and densitometer plotting already; and at my age now my mantra is, "If it ain't broke, don't fix it."

 

[Helge]

I was interrupted by dinner. But I was going to add that the postulate that a very long dilute development effectively preempts the need for a pre-rinse might seem to make sense, but we never really know unless all the pertinent variables have been objectively tested an compared. Incidental findings don't cut it for me; but I'm in no mood or need to make those kind of tests myself. I've certainly done more than my fair share of film testing and densitometer plotting already; and at my age now my mantra is, "If it ain't broke, don't fix it."

Makes you wonder why you consider one incidental finding better than the other?

Blind tradition and habit? Is that really good reason alone? At any age?
One has the air of a religious rite. The other as of now, has something to recommend it.

Not telling you personally to change. But this board in its twenty years of existence seems to be about helping “the many” get the best results from film.

 

[DREW WILEY]

Well, there was a time when certain people actually did a lot of testing and finally published the results. Now, not only have films themselves changed, but today, with the web as the primary mode of communicating opinions, everyone seems to be an instant expert, regardless of topic, homework or not. And nothing apart from politics and conspiracy theories seems to catch fire faster than alternative developers. I wasn't terribly long ago that WW III almost broke out over which exact tweak between twenty competing pyro formulas was the very best, and why. And that was mostly among older guys with a LOT of experience. Now it seems all it take is a pinch or Greek yogurt or cactus juice thrown into D76, and it starts all over again, either in fun sense, or more often, as nonsense.

 

[Helge]

Well, there was a time when certain people actually did a lot of testing and finally published the results. Now, not only have films themselves changed, but today, with the web as the primary mode of communicating opinions, everyone seems to be an instant expert, regardless of topic, homework or not. And nothing apart from politics and conspiracy theories seems to catch fire faster than alternative developers. I wasn't terribly long ago that WW III almost broke out over which exact tweak between twenty competing pyro formulas was the very best, and why. And that was mostly among older guys with a LOT of experience. Now it seems all it take is a pinch or Greek yogurt or cactus juice thrown into D76, and it starts all over again, either in fun sense, or more often, as nonsense.

These findings are a little more than random nonsense or idle musings, I’d say.

 

[DREW WILEY]

Where everything is mostly idle musings, one more doesn't hurt. But there are benefits to going back behind web days, when it wasn't so ridiculously easy to state just anything and have it taken into account. In some ways, I kinda admire how darkroom work welcomes a bit of alchemy and mystical wizardry; in other ways, I prefer how films, papers, and developers etc have real science and industrial quality control behind them, with predictable results. There are two sides to the coin.

 

[Vaughn]

Predictable results through science, alchemy and mystical wizardry, with enough chance tossed in to make it a worthwhile exploration.

 

[Helge]

Where everything is mostly idle musings, one more doesn't hurt. But there are benefits to going back behind web days, when it wasn't so ridiculously easy to state just anything and have it taken into account. In some ways, I kinda admire how darkroom work welcomes a bit of alchemy and mystical wizardry; in other ways, I prefer how films, papers, and developers etc have real science and industrial quality control behind them, with predictable results. There are two sides to the coin.

So what is it? You like mysticism or not?

Old books are gold. But even back then a lot of ingrown tropes was repeated verbatim.

Look up any textbook up to the eighties about airfoils and you see the same old crap about air moving faster on top resulting in lower pressure and suction.
That is one especially grating example from another realm. There are a multitude of less blatant, but still vexing and confusing ones in film books from various decades.

If the internet has done anything qualitatively better, it’s giving fast access to many points of view.
That you need a strong bullshit detector and good sense of logic is the downside.

 

[Vaughn]

...

Look up any textbook up to the eighties about airfoils and you see the same old crap about air moving faster on top resulting in lower pressure and suction.
That is one especially grating example from another realm. ...

Lower pressure is created on top of the wing than below the wing due to the air flow over the airfoil -- the air moving faster over the top than the bottom. This creates lift. That is science. You must be referring to the refinement in the science behind the lift. That refinement is just that it is not the fact that air has a longer way to travel over the top of the wing that causes the lift...but the shape (curvature) of the airfoil.

How wings really work

A 1-minute video released by the University of Cambridge sets the record straight on a much misunderstood concept – how wings lift.

www.cam.ac.uk

 

[Helge]

Lower pressure is created on top of the wing than below the wing due to the air flow over the airfoil due to the airmoving faster over the top than the bottom. This creates lift. That is science. You must be referring to the refinement in the science behind the lift. That refinement is just that it is not the fact that air has a longer way to travel over the top of the wing that causes the lift...but the shape (curvature) of the airfoil.

How wings really work

A 1-minute video released by the University of Cambridge sets the record straight on a much misunderstood concept – how wings lift.

www.cam.ac.uk

I have a feeling he is either misquoted, or is slightly confusing himself.
Lift is almost pure action-reaction. There is a tiny amount of lift to be derived from pressure differences with a moving airfoil, but it's very small.
In fact pressure differences are to be avoided as far as possible, as they create turbulence and drag.
A huge mass of air changes direction back and down and creates lift and forward motion.
Flat airfoils work fine. Curving them is only a second order optimization.
You can even turn an airfoil around the wrong way and still create lift. Planes can fly upside down after all.

Quick, without looking it up, why does the seasons change, and how does the moons phases appear?

You might know the correct answers (tilt and rotation of the earth axis, and the Suns orientation towards the moon), but a shockingly large amount of people who should know better does not. Even some people educated in the sciences!
The most common idea is that it is Earths orbit and distance around the Sun that creates the seasons. And many people believe that it is Earth that is casting a shadow on the Sun.

Wrong internal models and vaguely and hastily transferred notions and ideas play a very much underestimated role in shaping society and our ideas of what is right and wrong.

 

[Sal Santamaura]

...Look up any textbook up to the eighties about airfoils and you see the same old crap about air moving faster on top resulting in lower pressure and suction...

Not crap, just not the entire picture:

No One Can Explain Why Planes Stay in the Air

Do recent explanations solve the mysteries of aerodynamic lift?

www.scientificamerican.com

I'm not Doug McClean, but The Boeing Company does send me a pension payment monthly.

Back on topic, as I wrote way back in this thread:

"Time to do a thorough search of the PHOTRIO archive. It's replete with threads on this subject. You'll find that presoaking/prerinsing/prewashing (take your pick of terminology) in rotary black and white processing neither has any deleterious effect on development nor can be said to definitively result in an increase or decrease in required development time. That varies with each individual film/developer combination; some need more, some less. Only testing of one's own materials will provide a useful answer."​

 

[Vaughn]

And some people say the sun sets. Language is pretty cool. George Carlin was fun. So was the Wizard of Christchurch.

Thanks, Sal, good reading! Always fun to find things are more complicated than one can imagine. Got to keep some mysteries around.

 

[Helge]

Not crap, just not the entire picture:

No One Can Explain Why Planes Stay in the Air

Do recent explanations solve the mysteries of aerodynamic lift?

www.scientificamerican.com

I'm not Doug McClean, but The Boeing Company does send me a pension payment monthly.

Back on topic, as I wrote way back in this thread:

"Time to do a thorough search of the PHOTRIO archive. It's replete with threads on this subject. You'll find that presoaking/prerinsing/prewashing (take your pick of terminology) in rotary black and white processing neither has any deleterious effect on development nor can be said to definitively result in an increase or decrease in required development time. That varies with each individual film/developer combination; some need more, some less. Only testing of one's own materials will provide a useful answer."​

It’s crap when the author passes off a snippet of something poorly understood by most and hard to explain by real experts as The explanation.

I fail to see how quoting yourself is helpful?
Give us some actual links. Don’t assume we haven’t done a search.

Emulsions are different, but they share some fundamental basics that are only bent between films, not totally altered.

Relativism doesn’t work, and is like kissing your sister, not the real thing.
You are talking optimization.
Too early optimization, is a cardinal sin.
Getting the best result requires you to optimize down the right path.

 

[Sal Santamaura]

...I fail to see how quoting yourself is helpful?...

Only helpful to those who read and consider what's posted.

...Give us some actual links...

I've been on forums long enough to have reached the point of not doing others' work for them.

...Emulsions are different, but they share some fundamental basics that are only bent between films, not totally altered...

There's no useful way I can respond to that other than by once again quoting myself:

"...presoaking/prerinsing/prewashing (take your pick of terminology) in rotary black and white processing neither has any deleterious effect on development nor can be said to definitively result in an increase or decrease in required development time. That varies with each individual film/developer combination; some need more, some less. Only testing of one's own materials will provide a useful answer."​

 

[Sirius Glass]

Only helpful to those who read and consider what's posted.



I've been on forums long enough to have reached the point of not doing others' work for them.



There's no useful way I can respond to that other than by once again quoting myself:

"...presoaking/prerinsing/prewashing (take your pick of terminology) in rotary black and white processing neither has any deleterious effect on development nor can be said to definitively result in an increase or decrease in required development time. That varies with each individual film/developer combination; some need more, some less. Only testing of one's own materials will provide a useful answer."​

I agree. Presoaking et al does not change the development time as posted by any film manufacturer or Jobo. YMMV but I really doubt that it has any scientific basis but it may change based on what you ate today for breakfast.

 

[Sal Santamaura]

..."...presoaking/prerinsing/prewashing (take your pick of terminology) in rotary black and white processing neither has any deleterious effect on development nor can be said to definitively result in an increase or decrease in required development time. That varies with each individual film/developer combination; some need more, some less. Only testing of one's own materials will provide a useful answer."

I agree. Presoaking et al does not change the development time as posted by any film manufacturer or Jobo. YMMV but I really doubt that it has any scientific basis but it may change based on what you ate today for breakfast.

Actually, you don't agree. Unless your post adds the word "necessarily" between "not" and "change." Also, the required development time for a given person's darkroom equipment and agitation regime frequently differs from the times posted by film manufacturers or Jobo, which are appropriately referred to as starting points for individual tests.

In rare cases, presoaking doesn't change the required development time at all. For all other cases, it either increases or decreases the required development time. Once again, only testing of each film/developer combination will reveal reality.

 

[Helge]

Only helpful to those who read and consider what's posted.



I've been on forums long enough to have reached the point of not doing others' work for them.



There's no useful way I can respond to that other than by once again quoting myself:

"...presoaking/prerinsing/prewashing (take your pick of terminology) in rotary black and white processing neither has any deleterious effect on development nor can be said to definitively result in an increase or decrease in required development time. That varies with each individual film/developer combination; some need more, some less. Only testing of one's own materials will provide a useful answer."​

Just to recap.
You’re quoting yourself, quite a banal post with circular reasoning and postulates, telling us to do a search. Supposing we haven’t come up with that idea on our own.

 

[Helge]

In rare cases, presoaking doesn't change the required development time at all. For all other cases, it either increases or decreases the required development time. Once again, only testing of each film/developer combination will reveal reality.

Not saying you are wrong or are pulling things out of thin air, but I’d love to see some references to books, papers or links to data.
Including your own concrete experiences, that we could do our own peer review of.

 

[Vaughn]

... Once again, only testing of each film/developer combination will reveal reality.

As will the resulting expressive prints -- if that is one's goal.

 

[Helge]

As will the resulting expressive prints -- if that is one's goal.

Regardless, for every one in ten thousand who has the time and equipment to do step wedges and densitometry for a dozen combinations. There will be thousands of others who would just like to follow a recipe exactly and get the best result.

Doing tests in a real meaningful manner, is very hard and difficult work. Not to speak of expensive.

It’s very easy to fudge yourself into a corner, and call it “experience” and “my own special blend” and really have confirmation bias and familiarity bias make you think you have something better.

I’m not advocating following directions like a robot. Knowing something about the process will help you de-bug it if you get off results.

But A. It can be difficult to spot off results especially with negatives, with little or nothing to compare against.
B. Fudging around and tinkering in a process with so many variables is pointless, because you never really know cause and effect with much certainty.

 

[Vaughn]

I spent two years testing and discovering the possibilities of a new-to-me process from a recipe in a magazine. Having never seen a carbon print, I did not even know what a print was suppose to look like. Try this and that, keep notes, think about what may be happening chemically and physically in the process (no internet forums on the process in 1992). Look at the results and guess where to go next, make notes, and try this and that -- and repeat. See something unusual happening, figure how to take it further by understanding the process better. I made it more difficult for myself by changing the exposure/development of the film while also changing the receipe of the 'glop'. But loved juggling two variables!

But all my testing was done making prints -- no step wedges, test strips, densitometers. Just prints with the goal taking what I experienced in the light of the redwoods and putting it on paper...with no one part of the process being more important than another.

After thirty years still learning. But who needs certainty? Some folks do -- I certainly don't. Sensitizing some carbon tissue tonight for printing in the morning...time for tea!

 

[Randy Stewart]

I use a Unicolor film drum with up to 8 rolls of 35mm, I follow the old Unicolor directions and reduce development time by 20%, no mention of a pre soak. If I was using C 41 or E 6 at a 100 degrees F, I would likely do a presoak to temper the drum and reels and bring up to 100 degrees F before developer.

I have used a Unicolor Film Drum on a Unicolor roller base since early 1980s to process all of my C-41 and E-6 films. I use the standards times and temperatures for the processes. As does Paul, I use a sequence of fills and dumps to warm the film, reels and insulated drum to operating temperature.

 

[lecarp]

Now I'm confused, If you pre-soak a wing at sunset in the fall, does it have more or less lift?
Oh, and does it matter if there is film onboard?

 

[Helge]

Now I'm confused, If you pre-soak a wing at sunset in the fall, does it have more or less lift?

Less. Presoak is out. Pre-exposure soak is in.
And laminar flow is always best on top.

Oh, and does it matter if there is film onboard?

Now you are just being downright silly.

 

[pentaxuser]

Now I'm confused, If you pre-soak a wing at sunset in the fall, does it have more or less lift?
Oh, and does it matter if there is film onboard?

It about sums up where we have got to in this thread

pentaxuser

 

[Randy Stewart]

Interesting comments in #3 and 4. Does that mean that IlfordPhoto is giving the wrong advice when it recommends that that dev times be reduced by 10-15%?

Rick A, can you tells us why it reduces airbells? If this is backed by science then this may be important to the OP of another thread where no matter how much he raps the tank he cannot get rid of what he is conviced are airbells

1. The Ilford recommendation is to those who have established development time based on intermittent agitation when moving to rotary processing with continuous agitation. For its B&W films, Ilford recommends no pre-soak.

2. The idea that a pre-soak will reduce airbells when loading the following developer is based, I suppose, on the assumption that an airbell is more likely to be left between film edge and spiral reel flange if the reel is dry, and less so if the reel and film are wet. I doubt that there is any objective study of that as fact. Moreover, it's practical nonsense, in that an airbell can be dislodged with a simple rap of tank on table, so where is there any logic in using a pre-wash for that? It's a solution looking for a problem.