Pre-rinse or no pre-rinse

Rick A · Jun 25, 2015

I think on shorter development times, presoak would make a difference, say times down around 5 minutes you might need to add some time. I don't see any difference with longer times, I don't add any time on for presoak. I don't think it takes very long for the developer to displace the water in the emulsion, but I'm no scientist. Also, my procedure and times are for my use, I don't care what others do, it works for me.

canuhead · Jun 25, 2015

never did it pre-internet and while growing up and while working as a lab tech in newspaper darkrooms. tried it with rotary and didn't see any difference from non pre-rinsed film so no longer pre-rinse.

Nick Kanellos · Jun 25, 2015

I figure with a Jobo and its short development times, I'd presoak. The time it takes for the developer to displace the water in the emulsion, IMHO should help ensure evenness of development.

RalphLambrecht · Jun 26, 2015

Nick Kanellos said:
I figure with a Jobo and its short development times, I'd presoak. The time it takes for the developer to displace the water in the emulsion, IMHO should help ensure evenness of development.

or not if the water didn't get everywhere uniformly

RobC · Jun 26, 2015

so how many people developing colour film use pre-soak and for those developing colour film without pre-soak do you get uneven film development?

If the answer is no we don't use pre-soak and we don't get uneven development, then that should tell all those using pre-soak that they are fixing a problem which doesn't exist.

If your dev tank fills fast enough you won't get uneven development and if you do then then its probably due to something else such as bad agitation routine or flow patterns caused by your tank rotator.

Photo Engineer · Jun 26, 2015

With color, tempering the equipment is also an issue and is why a prewet is so important.

PE

RobC · Jun 26, 2015

Photo Engineer said:
With color, tempering the equipment is also an issue and is why a prewet is so important.

PE

A jobo processor has the tank sitting in a tempering bath which also keeps the tank and chemical at correct temperture during processing. So why does that require a pre-soak? Or are you saying the jobo tempering bath which the tank is sitting in does not keep the tank and chemicals at the correct temperature?

And, with all your vast experience, can you tell us what temperature a 38deg colour chemical poured into a developing tank at room temp, say 20deg would end up being? Maybe 37deg? well if thats the case just set your chemicals to 39deg before pouring into tank.

And then we come to B+W. If dev is at 20deg and room temp is 20deg and tank will therefore be at extremely close to 20deg, then why would a pre-soak be necessary?

All seems like a lot of foklore to me.

Photo Engineer · Jun 26, 2015

Rob, those tests were done in a previous thread to show how low the temperature inside of the tank drops in spite of the external tempering. The reels in air take a long while to warm up and the tests show it. Many have done this to verify the claim that the inside of a Jobo tank does not get to 100F very quickly or easily. That is one reason Jobo suggests use of a prewet.

The temperature drop is significant enough that the images are affected, and no, it is not 1 degree, nor is it easily corrected as it is a variable depending on amount of film, tank, reel and etc. The prewet damps all of that out as well.

The Jobo tempering system does an excellent job of keeping the temp at the desired value once it is achieved by a prewet.

As for B&W, temps can be high or low in summer and winter.

PE

DREW WILEY · Jun 26, 2015

The trick with any drum system is getting the air inside closer to ideal process temp, and not just the outside of the drum via a water bath. The better the drum is mfg, the better it will insulate to keep temps inside the drum consistent longer. For instance, my best drums are made of expensive noryl plastic - an excellent insulator - followed by thick ABS, then thin ABS as the least insulating. But that very virtue becomes a liabilty if you're relying only on external temp control. If you are relying on outside temp, thin stainless steel is preferable for exactly the opposite reason: fast temp transfer. Nobody is going to pay for grade 316 large stainless drums necessary for typical paper sizes, or want to deal with the extra weight. Therefore the simplest solution is just to pre-temper the inside of the drum with a wetting step. I also find this absolutely necessary to get rapid even spread of the developer on large color prints to avoid streak or drip marks.
In fact, during the fill phase - the first 10 seconds of the development cycle, I speed up the drum rotation, then slow it back down for the
duration of the cycle. And with film, whether trays, hand-inversion drums, or automated drums, I have standardized on a prewet with
every film & developer combination I can think of; and given my consistent results, see no reason to change that habit. With tray development of sheet film it's vital in my opinion. When sheets first enter a fluid they tend to stick together, and that's the last thing you want when development starts.

Doc W · Jun 28, 2015

A follow-up question: if I were going to use a pre-soak/rinse, what would be a good starting point? Some of you have said too little presoak is not a good thing, nor is too much presoak. So, in my situation (FP4, HC-110, Jobo ATL-3), what would be the optimum pre-rinse time? One minute, three, five...?

RalphLambrecht · Jun 29, 2015

Doc W said:
A follow-up question: if I were going to use a pre-soak/rinse, what would be a good starting point? Some of you have said too little presoak is not a good thing, nor is too much presoak. So, in my situation (FP4, HC-110, Jobo ATL-3), what would be the optimum pre-rinse time? One minute, three, five...?

5 minutes is neither too short nor too ong; good starting point

Doc W · Jun 29, 2015

RalphLambrecht said:
5 minutes is neither too short nor too ong; good starting point

Thanks, Ralph. Would a pre-soak increase or decrease development time?

Rick A · Jun 29, 2015

My Jobo manual recommended a minimum of three minutes for pre-soak, I still use that for my process.
I don't think it adds much, if any when using longer development times, it may have an effect at shorter times. I'm no scientist, but it may take only a few seconds to maybe half a minute to displace the water in the emulsion with chems, I always choose longish developing times to avoid streaking and uneven development issues that short times could produce, for me 30 seconds either way doesn't really show.

Photo Engineer · Jun 29, 2015

I use 2' at 100F for color and 3' at 68F for B&W. This is in a rotating Jobo with the tank at the same temp.

PE

Sirius Glass · Jun 29, 2015

Photo Engineer said:
I use 2' at 100F for color and 3' at 68F for B&W. This is in a rotating Jobo with the tank at the same temp.

PE

I only do 2 minutes for color at the 100°F range.

grahamp · Jun 29, 2015

David Allen said:
[...]
I read this all the time but, just think, how much is actually being carried over 1ml?, 2ml?. I have exclusively used a reusable two-bath developer for the past 15 years. I have never experienced any problems with dilution of the first bath BUT, by using a pre-soak, it does keep the first bath looking much clearer as the anti-halation dye is removed during the pre-soak
[...]

www.dsallen.de

I go by how much volume drop I get when I drain my Jobo compared to the volume put in. The first bath always drops more than the second or subsequent one, and I can see the difference by eye. It is in the order of 25-50ml. On a tank using maybe 270ml, that is significant. It is testable, and may vary with tanks and spirals.

Dwayne Martin · Nov 28, 2015

If you don't pre soak doesn't that mean your developer will be mixed with the anti halation dye? Does it matter?

Photo Engineer · Nov 28, 2015

No, it does not matter.

Ronald Moravec · Nov 30, 2015

I did C41 in Jobo. The instructions called for a degree or so warmer water bath, run loaded film drum for 5 minutes to achieve 100 deg for reels, tank & film. The developer probably lose s some temp going down the lift.

Never had a problem. The only key is keep the rotation speed up for 60 sec or you can get marks.

Pre-rinse or no pre-rinse

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