use developer dilution to tame high water temps?

[Mark Sampson]

I've started testing; will report back when I have the answer. Thanks to everyone who has commented so far!

[Duolab123]

The old Kodak formula books say you can use regular developers like D-76 up to 90F, by adding sodium sulfate. There's a bunch of info in the old Kodak data books for "Tropical Development " start with prehardener, modify the developer, longer stop bath times, hardening fixers and post hardening. I'm not sure how relevant all the hardening baths are, with modern films. Definitely would want to make sure you keep solutions close to the same temperature throughout the entire process. .

Cold water from the fridge sounds easy to me.
Best Regards Mike

[Doremus Scudder]

The problem is not the water temperature per se, rather the short developing time. Adjusting developer dilution should help here.

When working with extreme developer dilutions, it is important to ensure you have enough stock solution for the volume of film you are processing. This might mean a larger total volume that you are currently working with. I've not tried Pyrocat, but I would imagine that diluting, say, 1+1+150 might slow it down enough to get your times more manageable. Check out Sandy King's website and read what he has to say about dilutions. I found this very quickly from http://www.pyrocat-hd.com/html/mixing.html

"All of the Pyrocat formulas are acutance developers that give good pictorial rendition when used at dilutions of 1:1:100 to 2:2:100 with normal agitation. When used at higher dilutions with reduced agitation they become high acutance developers with very pronounced adjacency effects."

And, of course, you'll have to test for your development time. However, I've had good luck "guesstimating" starting points with the following: half-strength = a doubling of the developing time. With 1+1+150 I might try 150% of the normal developing time as a starting point.

Hope this helps,

Doremus

[docw]

I develop in a Jobo ATL-3 and use HC-110. Normally I develop at 20C because the ground water is usually much lower and with the Jobo, it is easier to raise the temperature rather than lower it. I take a few weeks hiatus from development in the hottest part of the summer. However, this year, I am really twitching to develop a recent batch and the groundwater has hit almost 24C. So I am going to have to recalibrate and I will be facing some of the issues mentioned here.

My shortest development times will likely be under 5' so I am going to have to increase the dilution. In order to maintain the minimum amount of developer per sheet, there will be greater volume in the tank and perhaps fewer sheets per session. I don't like to run the Jobo absolutely full simply because it is getting old and I don't want to wear out the motor.

All of this is not that big a problem. I am just impatient. I live in Canada and the water temperature will be well under 20C in the not too distant future!

[Stephen Thomason]

You may want to check your calculations again. From the MDC that recommends 18 minutes @20C for FP4+ exposed at ISO100, 27C would give 8 minutes 56 seconds. That is for Pyro at 1+1+100. That should be easily doable.

[LabRat]

My understanding of developer temps is that the emulsion thickness expands to many times it's thickness (esp in the developer), and allows greater diffusion of dev into the emulsion the more swollen it is... And swells more the warmer the solutions... So dev time is based on this rate of diffusion that allows greater activity/penetration the warmer the temp is... (And >80deg it can swell past the point where the swollen upper layer of the emulsion will not shrink back to register exactly with the exposed grain areas lower in the emulsion thickness, resulting in un-sharpness, and in worst case, (if it breaks up) classic reticulation, hence all of that hardening required with tropical/warm weather developers/developing...)

Some very dilute formulae will work under 80deg to cut your dev time, but by the time you wire it in, the leaves may be falling in your locale... You might save the important film processing for a few weeks from now...

Steve K

[IanG]

You may want to check your calculations again. From the MDC that recommends 18 minutes @20C for FP4+ exposed at ISO100, 27C would give 8 minutes 56 seconds. That is for Pyro at 1+1+100. That should be easily doable.

I'm not sure how you get to that time, temperature coefficients differ depending on the developer, and particularly the developing agents, my experience with Pyrocat HD is that 18 mins @ 20ºC is equivalent to 11 mins 8 seconds @ 27ºC. That's based on approx 10 years of using Pyrocat HD here in the UK and Turkey and a variety of films.

Ian

[Stephen Thomason]

Ian, the time was from the Massive Development Chart time/temp conversion calculator - I am relatively sure that it is pretty much just a straight line function.

I would greatly appreciate it if you would share your experience with PyroHD at various temps - it would be most helpful to me - Summers here in coastal South Carolina are a bit on the warm side also. My tap water yesterday was 28C.

Stephen

[j.e.simmons]

My water here in coastal Georgia is 78F. I've had good experiences with Pyrocat and conventional 400 speed films - Tri-X, Hp5, even old Forte 400 from the freezer at 15-minutes with 1-minute initial agitation and 10-second agitations at 5 and 10-minutes.
I should add that I have a huge SBR here and use this method for some compensation.

[Mark Sampson]

Thanks everyone!
I chose a simple solution; every water pitcher in the house filled and into the fridge. when 68F is reached, begin. Normal dev time in the Nikor tank is about 11 minutes; N-1 about 8.5. Washing is accomplished with the old Leica recommendation of five changes of water. Temp varies a few degrees from start to finish, but the negs look good. The project is 50% processed now, the duplicate negs will have to wait until next week. In a way, I enjoy using such low-tech methods; quite a change from my Kodak days. Of course the prints will tell the real story, but they are month off at least.