PDA

View Full Version : Gotchas or disadvantages of higher temperature processing



swmcl
10-May-2014, 14:22
Hi,

I'm thinking of standardising all my development at higher temps so that I have a greater portion of the year available. I live in a hotter climate than many Europeans and North Americans and I think it might be better for me to set my heater to 24C rather than try to keep things at 20C. It also means I could do things during the day more often rather than try to get things happening at some ungodly early hour!

Are there any particular disadvantages to doing this? Is it possible to use all developers (paper and film) at higher temps? Do some developers become difficult to use - perhaps they oxidise or do something else.

Are all the other chemicals stable at higher temps?

Would you not have a pre-wash at higher temps for example...

I am aware of the possibility of very short dev times too. I would try to adjust things to have a 'normal' film dev at 8 to 12 mins ideally.

This is a general question respecting the vast experience on this forum.

Cheers,

Steve

jbenedict
10-May-2014, 14:56
Here's a link to a Google Book's excerpt from Steve Anchell's "The Darkroom Cookbook"

http://books.google.com/books?id=laB5AgAAQBAJ&lpg=PA47&ots=iYY5tqPEQe&dq=tropical%20film%20developers&pg=PA45#v=onepage&q=tropical%20film%20developers&f=false

Scroll down the linked page to find the section of tropical development procedures.

There are some charts showing times for higher temperature developing and types of additives such as sodium sulfate to alter the developing characteristics.

ic-racer
10-May-2014, 17:25
For many years table-top processors, like the popular Jobo units, have been implementing a heater to maintain bath temp. This only works when developing temperatures are above the ambient temperature. One popular developer designed for 24C is T-max developer and I'm sure others will chime in with their favorites. One example of a developer not suited to 24c is HC110, due to the short development times.

jbenedict
10-May-2014, 17:40
For many years table-top processors, like the popular Jobo units, have been implementing a heater to maintain bath temp. This only works when developing temperatures are above the ambient temperature. One popular developer designed for 24C is T-max developer and I'm sure others will chime in with their favorites. One example of a developer not suited to 24c is HC110, due to the short development times.

What kinds of short HC-110 times are you talking about? It could be diluted to give a longer development time just as long as there is enough of the 'juice' in there to actually do the developing. I have used HC-110 highly diluted to do compensating development. I can't remember the amounts needed for all of film sizes but do remember that to develop 120, it needed to be done with one reel in a four reel tank and use the volume of developer one would use to process four rolls of 120 if it were at regular strength. I'll have to look up the exact dilution but it was something like 1 to 30 ( 1 oz HC-110 stock, 30 oz water- maybe weaker.) and development time was about 25-30 min. with a five second agitation every 5 or 6 minutes.

I bought my Jobo used and the previous owner told me that, if the summer environment got too hot (he was in AZ), he would turn the heater off and put ice cubes in the tempering water to get it down. If it got too far down, he would turn the heater back on. Kind of fiddley but the temp only needed held for the 20 or so minutes of a 68-70 deg. developing process so it wasn't like it needed to be spot on for an hour.

ic-racer
10-May-2014, 19:36
I was getting about 4 minutes with HC110 at 24c and t-max or tri-x when I tested it. T-max developer works out to around 6 minutes and gives better shadow detail to boot.

I'd recommend those contained 'ice packs' that one can use to keep drinks cool. I have also filled up some of the extra bottles with ice/water. The heater is on a thermostat, so no need to fiddle with it, just set it to the desired temp. I'd not put free ice in a Jobo water bath.

StoneNYC
10-May-2014, 23:58
You could always drop $3,000 on a new CPP3 that will cool itself down if it's too hot :)

swmcl
11-May-2014, 01:37
OK.

So the answer is ...

There are no chemicals in the photographic process that do anything other than work more energetically at higher temp. Perhaps pyro will be more oxidised but not by much... No toners, stabilisers, fixers, two bath concoctions nothin'.

Just gotta find a new 'normal'...

Jim Jones
11-May-2014, 05:49
Maintaining darkroom temperatures between 20C and 30C, and compensated with time adjustments for film and paper seems to work. Emulsions may be softer at higher temperatures, but with care that's no problem. Rapid filling and draining of film tanks becomes important. I always used a prewash for film.

Bruce Watson
11-May-2014, 06:24
Are there any particular disadvantages to doing this?

Depends on the developer, but yes, there are disadvantages. Developers that use more than one developing agent, for example, metol and hydroquinone (the so-called MQ developers, like Kodak D-76), are "balanced" for a specific temperature, typically 20C. As temperature varies, the activity level of the developing agents also vary, but they vary independently of each other. This in turn unbalances the mix, which results in a different development -- say, higher contrast with harsher tonality, or lower contrast with softer tonality.

IOW, more changes than just the development time.

If it were me, I'd start with a non-hydroquinone developer like XTOL, I'd dilute it to, say, 1:3, and reduce agitation to the low end of the range. Then do the Zone System tests to find my new EI and my "N" development time at my new temperature and workflow.

Oh, wait. I do have this problem. I use ice with my Jobo in the summer. :cool:

Martin Dake
11-May-2014, 07:00
You could always drop $3,000 on a new CPP3 that will cool itself down if it's too hot

I live in a warm climate and there are 2 things this brings...
1. High ambient temperatures
2. High tap water temperatures

I could turn the A/C down to get the house down to 20C but the tap water is still 25-26C.
I don't think a CPP3 can cool itself down to less than the tap water it is connected to.

Bob Salomon
11-May-2014, 07:10
I live in a warm climate and there are 2 things this brings...
1. High ambient temperatures
2. High tap water temperatures

I could turn the A/C down to get the house down to 20C but the tap water is still 25-26C.
I don't think a CPP3 can cool itself down to less than the tap water it is connected to.

But this will:

http://www.advantageengineering.com/smallWaterChillers/smallWaterChillers.php?ex=d1q81c-eep549-f5aspr&gclid=CJDs742GpL4CFSJqOgodn3QAZw

StoneNYC
11-May-2014, 08:18
I live in a warm climate and there are 2 things this brings...
1. High ambient temperatures
2. High tap water temperatures

I could turn the A/C down to get the house down to 20C but the tap water is still 25-26C.
I don't think a CPP3 can cool itself down to less than the tap water it is connected to.

What Bob said, or...

If you're really ingenious and you have one of those more modern refrigerators you can simply hook up to the tube that spits out the cold cooled water right from the refrigerator, that's some cold water ;)

Martin Dake
11-May-2014, 08:34
What Bob said, or...

If you're really ingenious and you have one of those more modern refrigerators you can simply hook up to the tube that spits out the cold cooled water right from the refrigerator, that's some cold water

Or dig a geothermal well and tap in to the 60F constant water temperature around here.

rcmartins
11-May-2014, 10:11
I have also been dwelling with this problem for the last 3 years. At my place from April till November ambient temperature water, and that is the temperature I have for the demineralized water used to make the working solutions, is above 20 C. There have been several threads around this topic and the conclusion I got has always been to create an isothermal bath in which I place my developer tank. To achieve lower temperatures I use ice. For those, like me, that try to do stand and semi-stand development lasting over half an hour, this can be a real nuisance as it is necessary to place small ice cubes when temperature decreases. At those times I feel like being an overly evolved PID controller using an under developed actuator (ice) :). So, even though I don't have much time, I decided this spring to replace myself and the ice and to buy 2 Peltier cells (replaces the ice cubes), a real PID controller, a power supply, a Pt100 temperature sensor and a metal tank. I have also bought a heating element to use both for film development and for carbon transfer print development. The Peltier cells further require heat paste/glue and heat-sinks with forced convection to cool down the hot junction. The cost of this set was around $130 but it could be cheaper than this (I have other requirements that make this a little bit costlier for me). Still, $130 is still much cheaper than most solutions that have been shown on this thread (besides the ice cubes, naturally) and they provide a much needed versatility in my darkroom.
raul

Mark Sawyer
11-May-2014, 11:33
OK.

So the answer is ...

There are no chemicals in the photographic process that do anything other than work more energetically at higher temp...

There are different reactions going on that are "balanced" for a given temperature, and the balance may shift. I'd expect the curves (shoulder and toe) to move a bit, the grain structure will be different, and the emulsion will be a bit softer and easier to scratch while handling. But 20C to 24C isn't too radical; I've dealt with worse in Arizona summers. As usual, your experiences will be your best guide!

Maris Rusis
11-May-2014, 14:28
Developer temperature control is a non-event for me in terms of anxiety about methods or results.

About 6 years ago I started the replenished Xtol batch that still works perfectly today after many square metres of film have gone through it. All films go into rep-Xtol, just at different developing times that have been calibrated for each by experiment. Replenished Xtol delivers a predictable activity versus temperature performance. For example Fomapan 400 comes out the same at 13 Celcius @ 23 minutes as it does at 34 Celcius @ 2minutes 45 seconds! In-between temperatures have known in-between times all determined by some one-off conscientious experimenting.

Now I just measure the temperature and instantly know the right developing time...except when I'm in a hurry or have a big batch of film to do. Then the pre-soak/dev/stop/fix/wash trays get floated in bigger trays of hot water, the temperature is measured, and processing proceeds apace. My last big session was 32 Celcius @ 3minutes 20 seconds and several dozen nice 4x5 negs (via 4 place slosher) came out as expected. If I'd processed at 20 Celcius my dev time would have been 11 minutes 20 seconds per batch and the job would have taken two days of darkroom "black" time instead of one.

Drew Wiley
12-May-2014, 09:31
Some emulsions (esp the bargain ones) don't like higher temps and are susceptible to edge frilling or emulsion running. But process times for film are rarely so long
that you can't control things with a simple water jacket modified with one or two of those little blue picnic box ice packs.

ridax
20-May-2014, 04:24
Beside the difference in individual chemicals' activity at different temperatures (mentioned above), the main problem is that chemical activity is much more dependent on temperature then diffusion is. And the balance between the speeds of diffusion and of the reaction itself is actually the thing that makes up the developer's "working style". The faster the chemical reaction is in relation to the diffusion, the more compensating the development is (meaning less overall contrast and degraded tonal separation), and the more edge effects are present (meaning increased apparent sharpness and sacrificed "3-dimentional" pictorial quality with the image looking more "cartoonish" in its sharp-focused parts).

So the common practice to dilute more and agitate less at higher temperatures (to keep development times long enough) is actually increasing the difference in resulting "development styles" badly. To make the developer work reasonably the same at high temperature, one should actually use it more concentrated (to make the development less dependent on diffusion) and increase agitation (to speed the diffusion up). But the development times should of course be much less, and here comes the risk of uneven development.

Also, maintaining low temperatures for long stand development seems to be not worth the effort (except to avoid calibrating for different temperatures - which really is a reason in itself IMO), as simply adding a little bit of agitation and shortening the development time at higher temperatures should give the same "stand-developed" results. And no agitation at higher temperatures would just enhance all the effects that stand development is known for.

That said, the difference between 20C and 24C is not enough to get all that "style differences" clearly visible with most of the developers and most of the emulsions - which all react differently to the temperature and agitation changes...

IanG
20-May-2014, 05:44
I process my films in Turkey at the water temperature, that's usually 27-28 C in the Summer, if the ambient temperature is too high I turn the air conditioning on.

Apart from the difference in processing times there's no differences between negatives processed in the Winter or when I'm in the UK.

Ian

Tim Meisburger
20-May-2014, 06:56
I'm with Ian and Maris. I use D23 and process at the ambient temperature, which usually yields here development times of 5.5 minutes. In the US and other cold places I've been I adjust times using the Ilford chart and have never noticed any difference.

tgtaylor
20-May-2014, 21:55
A Jobo processor holds a good 20 or so liters of water and thanks to its specific heat it is a fairly easy matter to raise or lower the processing temperature and keep it there using plastic bottles of frozen water stored in the freezer for just that purpose. I always process B&W film at 68F,color film at 100F, and print RA-4 at 95F.

Thomas

Kirk Gittings
20-May-2014, 22:27
How about an aquarium chiller for $139.00?

http://www.ebay.com/itm/Brand-New-Mini-Thermoelectric-Aquarium-Chiller-For-20L-5-Gallon-Fish-Tank-/261101699847?pt=Heaters_and_Chillers&hash=item3ccadfc307