How important is temperature in developing B&W film?

[Sparrow]

I work at the ambient temperature ... one of the few plus points of a temperate maritime climate and central heating

[Ezzie]

To put it this way. It is as important as the dilution of the developer. Change in either will require a change in timing. Warmer developement (than recommended by film and/or developer manufacturer) will often lead to fatter grain. Temperature can also be used to adjust contrast. So yes, I measure very carefully in order to get the results I want (every time).

[sevo]

Originally Posted by Ezzie

To put it this way. It is as important as the dilution of the developer. Change in either will require a change in timing.

Concentration (and agitation regime) changes can do a bit more than that - they will affect acutance (which is a effect of local in-emulsion depletion of the developer).

Temperature is merely proportional to timing, at least for times where the time lost over filling and emptying is negligibly small, and as long as you stay below the limits where the gelatin may peel - that is, don't develop at times below two minutes or temperatures above 40°C (not above 25°C for Efke and other unhardened film).

[Mablo]

Constant temperature is vital for consistent results. My negs became noticeably better when I started to place the tank in a 20C water bath between agitations. That helps to keep the developer temperature changing less than 1C during a typical ten minute developing session.

What comes to stop or fixer temperatures, I don't worry so much.

[whitecat]

Very important!

[zauhar]

In the summer my tap water is > 25 C, and I used to adjust time using the dev chart. This led to some blocky negatives with little detail. One RFFer cautioned that if you go much under 5 min dev time you can expect reduced quality, and I believe it.

A bag of ice from the corner store is the cheap and easy solution. I just put some ice in a plastic bag, it's easy to keep the temp within one degree of 20.

Randy

[Vincent.G]

I immerse my developing tank into a water bath maintained at 20 degrees celcius using ice cubes or cold water from the fridge. It is easier to maintain constant temperature with a bigger volume of water. The water in the water bath is then used for rinsing.

[Tim Gray]

I use mostly XTOL 1:1 and just use the times given for different temps in the XTOL pdf. I took the data in there and fit a line to them so I have times for 68-75 F or 80 F (depending on the film) in 1 degree increments. 90% of the time my tap water comes out somewhere in the range - if it doesn't I heat or cool it until it's in that range. The rest of my chems are kept indoors, so they are close enough to those temperatures as well.

So temperature is important, but I've not seen too much of a different if you adjust the times appropriately and you are inside the range of 68-80 F. I've kept pretty meticulous notes on all my film development, with times and temps for each roll, but have never really had a problem with any of them. I will say that even at the hotter temperatures, XTOL 1:1 never really gives you times below 5 mins (I think 7 is about the shortest for my films), so you don't have to worry too much about too short dev times.

[venchka]

Consistency and repeatability are more important than the actual temperature.
After beating my brains out trying to maintain the traditional, lower temperature in the Texas Inferno, I caved in and went with ambient temperature in my kitchen, ~75F. I printed out the linked PDF and keep it handy. I put pre-wash water, developer, stop water & fixer in a sink full of water a couple hours before developing begins. When it's time to develop, I look at the temperature, consult the chart and GO! Xtol 1:3 keeps my time above 7 minutes for comfort. Life is much better since I quit fighting tradition.
For the "average start to finish time" folks: My research found that over a ten minute span, the temperature of the developer rose to ambient room temperature in less than 3 minutes. The developer temperature was NOT the average of the start and end temperatures.

http://www.ilfordphoto.com/Webfiles/...0208211880.pdf

Wayne

[ferider]

I mostly use Rodinal. For the normal recipes (between 10 and 20 minutes), just a couple of added degrees will have really strong impact on film sensitivity and grain. So I keep it constant at 20 degrees, either by adding hot water or ice cubes to the water before I start. I agree with Wayne that consistency is even more important - here in California faucet temperate varies throughout the year.

I don't care about temperature when washing or fixing.

For stand development, development temperature matters less.

Roland.

[MIkhail]

Originally Posted by vinyljunky

Didn't find any threads on this topic, just curious to know how important temperature is in B&W developing? I always used water straight out of the faucet, but I recently measured the temperature and found it was 23 deg C/73.4 deg F (versus the recommended temperature of 20 deg C/68 deg F).

Does everyone measure the temperature for B&W developing? Has anyone noticed any issues with hotter/colder temperatures? Do any film/developer combinations need precise measurement?

It is really important. For example, if I had the described above situation, and the time of normal development of my film was 10 minutes (for 68deg F) I would keep it in development for 8 minutes insted. That important.
It is easy to control, why cheat on something so simple?

[funkydog]

Has anyone experienced reticulation in their negs from all that temperature yo-yoing (adding ice when the tempering bath warms up) , stop/fixer/wash at different temperatures - and everything way different from ambient air/water temperature)?

[whitecat]

Once I took control of my temp, I noticed a big difference. Stay consistent! I really think 2 degrees makes a difference.

[zauhar]

Originally Posted by funkydog

Has anyone experienced reticulation in their negs from all that temperature yo-yoing (adding ice when the tempering bath warms up) , stop/fixer/wash at different temperatures - and everything way different from ambient air/water temperature)?

Actually, I keep all the solutions in the same bath, and mix the developer with water at the target temperature (I figure the stop and fixer will be "close" by the time I am ready for them). I try to adjust the wash water to be close to that same temp, but in the Summer that is not possible. Have not had issues with reticulation.

Randy

[Dylan Hope]

Temperature is important in controlling grain and times to me. I used to be very particular about getting it to 21.5 degrees because I almost always push my films an additional 7% regardless of what speed it is shot at and that brings tri-x @ 800 in XTOL 1:1 to a cool 9:30, but lately I've mostly been satisfied with 21-22 degrees. I'll still aim for 21.5 though, especially if I know there's a good shot in the roll.
On the flip side, my friend channels Daido when he's in the darkroom, develops until he feels its about right, agitates erratically and sporadically and otherwise doesn't process in a repeatable way. His work comes out fine though. His only limit is 30 degrees celcius because of reticulation, but when I'm in the darkroom with him he goes by the massive dev chart app on my iPod.

It's a process that would make most film shooters cry.

[ferider]

After digging some in my archive ... this guy did some quantitative measurements for Rodinal:

http://home.arcor.de/piu58/fotoweb/a...ze/Rodinal.pdf

In case you don't read German:

"Je Grad Temperaturerniedrigung erhöht sich die Entwicklungszeit um einen Faktor von 1,13. Bei 2 Grad ist der Faktor 1,3 und bei 4 Grad 1,6."

Meaning

(starting at 20 degrees Celsius) "Every degree of temperature reduction increases the development time by factor 1.13. At 2 degrees the factor is 1.3, and at 4 degrees the factor is 1.6."

For example, 10 minutes in Rodinal 1:50 at 20 degrees is equivalent to 13 minutes at 18 degrees. He also comments on the different behavior of the developer when colder, including dark tones, grain, etc.

Roland.

[Jaans]

I am very particular about temperature control. I live in a sub-tropical climate, so sometimes you have to pay close attention to maintaining a constant 20C.

I have found the best way to do this, is have a small 500ml plastic bottle of water kept frozen in the freezer. When you want to develop, then if your developer is say 24 C, then simply drop the bottle in the jug for 45 seconds or so. The temperature will quickly drop down to the desired temperature.

After taking out the plastic bottle, wash the outside of it thoroughly, before using again or putting it back in the freezer. It is a simple and effective way for temperature control.

Some others use baths, which are also good. However, I find the above method faster, as the ambient temperature doesn't increase the developer temperature during development.

[alfredian]

Ilford does, or used to, have graph/gnomon in their technical specs sheets for every developer. You can view it on their website and find just about any film.

It allows you to see the proper time for any temperature within the acceptable range - a straightedge or transparent plastic ruler helps keep your eye on an even keel. Some films have a steeper slope then others, so a small temperature change can matter. I can't remember if their film spec sheets had a similar graph for different developers.

The developer time/temp graphs are small enough to print out, clip and put up on the wall, cabinet door, whatever, where you do your developing.

[Argenticien]

I use the Ilford compensation document mentioned above, so if something would take 8:00 minutes at 20 C, but 5:30 at 24 C, then, sure, I would do 5:30 if I'm at 24C. However, if I've added ice to tap water to get to 20, but hit 19.7 or 20.2, I will call it good and not futz around adding further alternating bits of hot water and ice to exactly nail 20 C. Further, I measure just the mixing water. When I add in the liquid concentrate developer, it is at ambient temperature (I don't bother pre-cooling it), so the overall working solution probably ends up not at the temperature I measured. There is so much other noise in the system anyway -- age/strength of concentrate; imprecision in measuring small quantities of same; extra or lost seconds of development when pouring chemistry in/out; making the exposure at f/5.6 or f/8 when the light meter called for f/6.7 but the camera has no half-stops; age and storage conditions of the film; imperfect shutter timings on 75-year-old cameras; etc.). There is a saying somewhere about "measure with a micrometer, mark with chalk, cut with an axe"; trying for perfection in my development temperature given the variability in all those other factors would be a similarly silly opposite, like "measure by pacing; mark with chalk; cut with a laser." Life is too short...

Full disclosure: I'm a hobbyist only. Might try slightly harder if my livelihood depended on the negs.

--Dave

[mike rosenlof]

I too work at ambient temperature. In my basement darkroom that varies from 18C to 22C over the course of the year. Generally very stable. I standardize on 20 deg C as a developing temperature and use the Ilford correction tables (in any of their film data sheets, I think) to adjust to the current temperature.

So, absolute temperature is not super important within a range, but developer termp relative to your standard temperature is critical.

[Sylvester]

Well... I develop room temperature and never get in trouble.
When it is about important shots I let my bottle in about 20°C water in my sink for about 20mins.
Never seen real changes, but my darkroom is always at 21-23°C...

[mackigator]

I've been developing at room temp but temp swings, winter to summer, are over a wider range. Perhaps 17-24 C. Reading this thread has me considering whether I shouldn't take the extra time to level off at a standard temp, instead of my usual adjusting on time.

Usually DDX or TMax dev and either Tri-X or TMax400.

[venchka]

Originally Posted by Jaans

...
Some others use baths, which are also good. However, I find the above method faster, as the ambient temperature doesn't increase the developer temperature during development.

My testing proved otherwise with Jobo drums spinning on a motor base. If I were using small tanks and let them sit in the sink with the rest of my liquids, I might be able to maintain something close to 68F. However, my tap water for 6 months of the year exceeds 80F. As a result, I turn the A/C down to maintain 75F-76F and use the Ilford chart linked earlier.

Wayne

[JohnTF]

Originally Posted by Chris101

102. We don't get into temperature dependent rate law until second semester cause you really need to have differential calculus as a prereq.

Come on, why not wait for partial differential calc?

It's a straight line, so m is constant, (the first derivative) -- never used calc in Chemistry-- it's more a physics thing for most ;-)

You did not think you were going to slip that one past did you? ;-)

Now, when processing digital images, the graphing function built in to the newest electronic brains of the newest GPS equipped cameras gives you a print out for all the film/developer combinations emulated and selected in the menu section of the camera, IOW you can select this to be done automatically and presented in the viewfinder.

John

[JohnTF]

Originally Posted by funkydog

Has anyone experienced reticulation in their negs from all that temperature yo-yoing (adding ice when the tempering bath warms up) , stop/fixer/wash at different temperatures - and everything way different from ambient air/water temperature)?

Had it happen a long time ago with Royal Pan 4x5, probably souped in DK60a and fixed in whatever was in the school darkroom, probably standard powder Kodak mixed in gallons.

I had somehow turned the hot water on to wash the negs, it probably soaked at least ten minutes before I paid attention, it was hot enough that the emulsion slid off the base in the corner I grabbed to pick up the film.

The emulsion firmed back up when it cooled/dried.


I don't know where the negative or any prints are, but the pattern was interesting, the cracks seemed to often follow the edges of the dark/light areas of the image.

I tried to duplicate it, but gave up after a while.

I think you need an old fashioned thick emulsion, no hardener in the fix, the hot wash -- in some combination.

I think modern thin emulsions would be difficult to reticulate as I imagine the manufacturers would consider it an advance to avoid reticulation, I even tried heating up some sheet film and putting it in the freezer, you can get some frost patterns. The areas of reticulation were probably close to a millimeter or more in size, was kind of a jigsaw appearance.

Other reticulation reactions may affect the image, but I am not well versed enough to intelligently comment,though that has not stopped me in the past. ;-)

John