"Pre-Wet"- Rinse after Development - Importance Of Plain Water

Doremus Scudder · Jul 16, 2016

There are some good reasons to pre-soak. Certainly when developing sheet film in batches and agitating by shuffling, it is necessary to pre-soak the sheets so they don't stick together in the developer. Pre-soaking also ensures that film, tank and reel are at the same temperature as the developer when it is introduced; this is the reasoning behind the recommendation to pre-soak from rotary development systems like Jobo. If there is no way to get film immersed quickly in the developer, e.g., pour-in time is too long and direct immersion is impossible, then a pre-soak will help with evenness (as will longer developing times). Finally, as some have noted, the anti-halation dye, which comes off in a pre-soak, may react with some developers and cause foaming; in this case, a pre-soak prevents this.

For most roll-film users and those who develop sheet film in large tanks with hangers or one-at-a-time in trays, a pre-soak is not necessary as long as temps are not extreme and the film can be immersed quickly into the developer. That is why it isn't recommended. That said, I have never seen a case where an adequate (i.e., not too short) pre-soak has caused adverse effects. I suspect the reason some caution that a pre-soak can cause uneven development is that unless you wait long enough for the emulsion to completely saturate with water (2-3 minutes minimum), there will be areas where the developer is taken up more quickly than others. Still I have never seen this.

Bottom line: pre-soak if you have a specific need to, otherwise forget it.

Best,

Doremus

mshchem · Jul 16, 2016

As mentioned above by Mr. Scudder. I have always pre-soaked when temperature is critical. Now that I have caved in to the Jobo miraculous developing machine I pre-soak most everything, Plus you get the joy of looking at the pink and purple water. I developed film for 25 years in Paterson tanks with never a pre-soak, Microdol-X, HC-110, XTOL 1+1.
I really like following the instructions given by the maker, Kodak came up with instructions for nearly every method, small, large, rotary etc. Kodak was like NASA to me back in the Day.
Read the instructions.
Best Regards, Mike

Jim Jones · Jul 16, 2016

A 1999 edition of the Ilford Product Data Guide, when discussing rotary processors, says, ". . . Standard development times . . . may need reducing by up to 15% for use in rotary processors without a pre-rinse because of the continuous agitation given in these processors. Alternately, if using a pre-rinse, use the development times for spiral tank development as a guide. Generally, however, a pre-rinse is not necessary and may lead to uneven processing." The guide does not mention pre-rinse in regard to spiral tank processing. I usually use pre-rinse, especially when developing up to 8 reels in a stainless steel tank at once. With a few drops of Photo-Flo it seemed to eliminate air bells. When developing sheet Kodak Tech Pan in Solarol for the Sabattier effect, it was absolutely necessary.

Photo Engineer · Jul 16, 2016

If you do not prewet for color, there is a temperature and pinhole problem that may crop up. If you do not prewet with B&W there is a potential for only a pinhole problem. I prewet for about 1 minute for both color and B&W and have for nearly 50 years! In addition, if you do not prewet any film properly, there is the potential for non-uniformity. You can demo that easily by running some water over a piece of film in a streak and then processing it. You will clearly see the streak. So, do it long enough and with good agitation at the right temperature (2 changes at least, with color) and you will have no problems.

A stop is useful for uniformity in sheet films and paper, but not so much with 35mm. Stopping will help consistency though from process to process, by halting development rapidly and uniformly. A rinse after an acid stop is often useful when using a neutral or alkaline fix. It extends the life by preventing any pH change.

I should add that all uniformity problems increase as format size of anything (film or paper) goes up!

As for rinsing after fix, this helps preserve any wash aid. But you still have to wash long enough to removed silver salts and hypo from your film and paper.

As far as a prewet is concerned, Kodak manuals showed this from the earliest examples. I posted one here on APUG from one manual that is over 50 years old! If you want it again, I'll look it up but you might want to try the other threads on this topic.

PE

MattKing · Jul 17, 2016

Ko.Fe. said:
How about RTFM? Did OP read datasheet from film, developer manufacturer?
If OP is not aware what it is, I'm happy to provide two examples:

http://imaging.kodakalaris.com/sites/prod/files/files/resources/j78.pdf
http://www.kodak.com/global/en/professional/support/techPubs/f4016/f4016.pdf

Both of which recommend that reels be dropped into a tank loaded with developer before the tank lid is added. How many people do that normally? I know I don't. And I'm sure that almost nobody who uses a changing bag does it that way.

And both of which say something like: "Prewetting sheet film may improve tray process uniformity." when discussing sheet film.
It may very well be that pre-wetting is the secret to obtaining even, repeatable development when one fills the tank with developer after putting the lid on.

Or maybe, it really doesn't matter much either way, as long as you are consistent with what you do.

Ricardo Miranda · Jul 17, 2016

Photo Engineer said:
If you do not prewet for color, there is a temperature and pinhole problem that may crop up. If you do not prewet with B&W there is a potential for only a pinhole problem. I prewet for about 1 minute for both color and B&W and have for nearly 50 years! In addition, if you do not prewet any film properly, there is the potential for non-uniformity. You can demo that easily by running some water over a piece of film in a streak and then processing it. You will clearly see the streak. So, do it long enough and with good agitation at the right temperature (2 changes at least, with color) and you will have no problems.

Of course it is going to show the streak. Had you not run water in a streak, you wouldn't have uneven development.
The film became soaked in water just on that point. When developer was added, the extra water already present in that part of the film acted as a dilution for the developer slowing down the effectiveness of the development in that area.
And that is the reason why the manufacturers of rotary systems recommend pre-soaking: to slow down development a bit given you have constant agitation.
Had that piece of film been uniformly pre-wet, than you wouldn't see any difference from a piece of film that hadn't been pre-wet.
And that's why no one can see any difference between a pre-soaking or not.
Pre-soaking as has been said by Ilford engineers and other good engineers isn't needed at all.
Unnecessary complication for 35mm in a normal small tank.

DF · Jul 17, 2016

OK then - assuming you're all developing film shortly after you've shot it, I learn here it needn't be. What if the film sits in a dry, brittle un-airconditiond apartment all summer long - 3 months before having a chance for development? Doesn't it get dry/brittle - 'little wet-job hurts or helps?

sepiareverb · Jul 17, 2016

I found a prewet helpful on the old ADOX Ortho film, got air bells on my first few rolls, added the prewet and they never returned. I use it on Efke 25, and on the Rollei Ortho also, but not sure I ever tested that. Without it as it became my replacement for the ADOX Ortho. I always give my sheet films a prewet as I find it easier to keep my timing correct with multiple sheets in the tray at once.

Never found long stored film to act any differently. I live in VT where we have super dry winters and super humid summers.

RalphLambrecht · Jul 17, 2016

DF said:
No, the supervisor of the new place said that the "pre-wet" before the developer is harmful, yet I've done it all along.

I stopped a pre-wet after having some water-spot issues and reading that Jobo advises against it;now, no more water spots but it seems to work for some folks;whatever works for you

Ian Grant · Jul 17, 2016

Brook Hill said:
Prescysol film deveoper instructions call for a 5min presoak before developing.

Tony

It (Pyrocat HD) works better without.

Ian

Lachlan Young · Jul 17, 2016

DF said:
OK then - assuming you're all developing film shortly after you've shot it, I learn here it needn't be. What if the film sits in a dry, brittle un-airconditiond apartment all summer long - 3 months before having a chance for development? Doesn't it get dry/brittle - 'little wet-job hurts or helps?

Triacetate base can get brittle after decades of improper storage - ie exposure to heat, moisture & acids. Three months is not going to make a difference.

Exposure to extreme heat for a prolonged period can fog film & no pre-wet is going to resolve that.

Photo Engineer · Jul 17, 2016

Ricardo Miranda said:
Of course it is going to show the streak. Had you not run water in a streak, you wouldn't have uneven development.
The film became soaked in water just on that point. When developer was added, the extra water already present in that part of the film acted as a dilution for the developer slowing down the effectiveness of the development in that area.
And that is the reason why the manufacturers of rotary systems recommend pre-soaking: to slow down development a bit given you have constant agitation.
Had that piece of film been uniformly pre-wet, than you wouldn't see any difference from a piece of film that hadn't been pre-wet.
And that's why no one can see any difference between a pre-soaking or not.
Pre-soaking as has been said by Ilford engineers and other good engineers isn't needed at all.
Unnecessary complication for 35mm in a normal small tank.

The point is that many who presoak get streaks because they do it improperly, not because it is a bad idea!!!

PE

Photo Engineer · Jul 17, 2016

DF said:
OK then - assuming you're all developing film shortly after you've shot it, I learn here it needn't be. What if the film sits in a dry, brittle un-airconditiond apartment all summer long - 3 months before having a chance for development? Doesn't it get dry/brittle - 'little wet-job hurts or helps?

Dry and brittle don't count. The film absorbs any moisture when soaked either in developer or water. The amount is limited by pH, hardness and temperature. Three months is a short time compared to many old kept films I have seen.

PE

RattyMouse · Jul 18, 2016

DF said:
I'm surprised that at the new darkroom I go to they do not pre-wet film before the "first" step which is developer (D-76), that is in fact harmful to the film. This I've done all along, in fact a good pre-wet with plainwater agitating sometimes for as long as 3 minutes.
They then go directly to stop bath without a rinse - filling your tank W/water than pour out 3-4 times.
After the fixer, again, no rinsing, directly to hypo clear.
I don't know If I need to consult my former mentor, give these new folks a lecture, or become more enlightened by hopefully someone here at APUG.

I have developed nearly 1000 rolls of film in that past 5 years. Never once have I used a pre-wet stage. I cannot imagine why one would do this. It seems entirely unnecessary and a complete waste of time and water.

Ricardo Miranda · Jul 18, 2016

Photo Engineer said:
The point is that many who presoak get streaks because they do it improperly, not because it is a bad idea!!!

PE

Thanks for clarifying it.

JW PHOTO · Jul 18, 2016

I like using a presoak and it's recommended for Wimberley's pyro that I use often. I use distilled water with one or two drops of LFN and pretty vigorous agitation. I keep hearing how Ilford says it's not needed, but did they ever say it wasn't recommended or harmful in anyway?

ericdan · Jul 19, 2016

I post soak for 30 mins no agitation to get rid of the purple.

removed account4 · Jul 19, 2016

since your instructor is running the show
i would do as your instructor says ( and not worry about it ).
some like to pre wet, some after, some in between, some never
none of these things really matter in the grand scheme of things.

M Carter · Jul 19, 2016

Man, hasn't there been hundreds of posts on pre-wetting here? That tend to resolve with "do what works for you, just do it consistently"?

I had a discussion about Rodinal and stop some time ago - it was suggested to me to stop with 20°c distilled water, no agitation, let it sit for one minute - more shadow detail. Then on to the fix. It seemed to open my shadows a bit, but never really did an empirical A/B test. I still do it today with no harm. But since I always do it as part of a consistent process that gives me printable negs, what's the harm - it may be a little secret sauce, I may have imaged it or I just got lucky with one particular roll, but at the end of the day, I'm getting the shadow and highlight detail I want. I'm not worried about an extra cup of water and an extra minute, I'm not a production shop, I don't feel like cutting up a roll of film and A/B testing it. (And I've found a water rinse before fixing keeps my fix from smelling...)

The one thing we seem to continually find about pre-washing is "it doesn't hurt anything" and some people feel "it helps solve some particular issue". There will never be an agreed consensus here short of specific cases (Pyro? Foam? Machine processing?) - which is one of the nice things about film and chemicals vs. moving a slider in Photoshop.

Xmas · Jul 21, 2016

DF said:
OK then - assuming you're all developing film shortly after you've shot it, I learn here it needn't be. What if the film sits in a dry, brittle un-airconditiond apartment all summer long - 3 months before having a chance for development? Doesn't it get dry/brittle - 'little wet-job hurts or helps?

No detectable effect...
My cine HP5 expired 2002 or so non sealed cardboard box is exposed and sits in my back log for more than a year before processing.
Single water stop between dev and fix, single water between fix and HCA.
The fix and HCA do go off quickly rules here allow discard in soil drain.

AgX · Jul 21, 2016

DF said:
I'm surprised that at the new darkroom I go to they do not pre-wet film before the "first" step which is developer (D-76)

I only learned about a pre-wet at Apug.

Photo Engineer · Jul 21, 2016

Look at #11 in the attached "demo".

Kodak has recommended this from day 1 when processing film. I learned to use a prewet and still do.

PE

removed account4 · Jul 21, 2016

interesting they dont' suggest using stop bath in that demonstration ...
they just say water, developer, the same water and fixer

Vaughn · Jul 21, 2016

Photo Engineer said:
Look at #11 in the attached "demo". Kodak has recommended this from day 1 when processing film. I learned to use a prewet and still do.PE

At college I learned that see-saw method, though we only used it to run the processed & washed film through a container of photo-flo before hanging in the drying cabinet. I still do it with my 120 film.

MattKing · Jul 21, 2016

jnanian said:
interesting they dont' suggest using stop bath in that demonstration ...
they just say water, developer, the same water and fixer

That only applies if you develop film while wearing a dress shirt and a tie .

"Pre-Wet"- Rinse after Development - Importance Of Plain Water

Doremus Scudder

mshchem

Jim Jones

Photo Engineer

MattKing

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Ricardo Miranda

DF

sepiareverb

RalphLambrecht

Ian Grant

Lachlan Young

Photo Engineer

Photo Engineer

RattyMouse

Ricardo Miranda

JW PHOTO

ericdan

removed account4

M Carter

Xmas

AgX

Photo Engineer

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Vaughn

MattKing

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