Temperature Maintenence

[focus_on_infinity]

I notice that in almost all videos on developing I've seen, and all tutorials, there doesn't seem to be any temperature maintenence once the developer is in the tank. i.e. other than agitation, the tank just sits there. I haven't yet seen someone set the tank into a water bath to hold temperature.

And while one may adjust one's processess accordingly for B&W, it seems like it just might be good practice if one also does or intends to do C41 or E6.

What say you? A good idea or not?

 

[koraks]

B&w is usually done at somewhere around 20C which is not too far off from the temperature of indoor spaces. Hence, temperature drift is usually minimal. As you say it's not such a good idea for color, but most people I know who do color use a rotary processor with tempering bath or at least just a tempering bath or water jacket. There are some threads arbour monitoring chemistry temperature in the developing tank when doing color processing, so you're not the only one thinking about this

 

[Luis-F-S]

I use a Zove VI compensating developing timer. Also, since my darkroom is at 68F, the temperature in the developing tray doesn't change much. Also, a lot of us don't post videos.

 

[kevs]

Hi focus_on_infinity, welcome to Photrio.

With B&W film, my technique is to presoak the film at 20c, bringing the film and tank to the correct temperature. I warm the dev to about 22c, which allows it to cool slightly during development and still maintain an average of 20c through the entire development time. That's a technique I learnt when developing colour films, where a three-minute first development is normal and using a waterbath is a faff.

 

[AgX]

Even Kodak had a manual for processing C-41 without water bath.

 

[Bill Burk]

Welcome to Photrio.

I use a compensating timer like the one Luis-F-S mentioned. My film tank is a 4-reel steel tank and I run water into a gallon pot when developing film. I put the probe under the running faucet. So I put the film tank in the pot of water to keep the tank at the same temperature as the water.

 

[Huub]

In winter it is pretty easy as the room temperture in my darkroom is set to around 20 C, so there is only minimal temperature drift. In summer that is different and my darkroom can get pretty warm with no AC available. In those case i try to cool down the developer to around 24 C and i do compensate for about 30 sec for the temperature rise during development. So instead of 10 min, it becomes 9.30 minutes. The results are good enough for the B&W i do.

 

[Bikerider]

I use a Jobo rotary processor for film development. Contrary to a lot of others I do not do a pre rinse to heat the tank when processing C41. My method it possibly a bit simpler and does not waste water. The developer, bleach and fixer are measured out and poured into the relevant measures followed by the bottles containing the rinse water. These are put into the processor and the tank filled with water up to the correct level. The developing tank containing the film is then left to float in the top half of the water bath which is still at the temp it was when filled. The power is switched on and left to raise the temperature up to the correct temp of 38C. As the temp rises this will slowly heat the tank to the same level as the chemistry. Once the chemicals, especially the developer, has reached the correct temp start the process by filling the tank with the developer and set the rotation at the SLOWEST speed. This is to reduce any frothing of the developer inside the tank. For bleach and fix stages the faster speed can be used, this ensures they are thorough.
The rest of the process is as normal. You will find that the negatives that are produced are consistently good with little variation of colour balance. This method has served me will for very nearly 30 years.

 

[Martin Rickards]

When I was doing C41 processing, I used an old expanded polystyrene box that was large enough for the tank to sit in with a couple of holes in the lid for the thermometer and the agitation rod for the Paterson tank. The chemicals were sat in the box while the film was loaded and excess water from the box was used as a prebath. That way the + 39ºC was easy to maintain.

 

[pwitkop]

In most cases, the developer temp doesn't drift enough through processing to be concerned with, particularly with black and white. If your using a higher processing temp (bigger temperature delta) or using a process that requires more precise temp control , i.e. color work, keep the tank in a tempered water bath during processing. If you're interested in checking how much drift you're seeing, pour the exausted developer into a beaker and check temp, you can check the temp during the processing with a Patterson tank. Stainless tanks will drift more, but they respond quicker to the water bath, plastic tanks are the opposite.

 

[takilmaboxer]

I've measured the temperature of the developer at the start and finish of the development and there is no significant drift over a 7-8 minutes span of time, even in summer when the tank is at 68 F and the room is 75 F. Important to me because I like TMAX 100 and I try to keep the temp within 0.5 F for consistency.

 

[Bill Burk]

In most cases, the developer temp doesn't drift enough through processing to be concerned with, particularly with black and white.

Exactly!

Not enough to worry about. Temperature drifts enough to be "significant" but I like to say you can be off 30% from what would be perfect negative development time and still get excellent prints from most of your negatives. So before you get too deep into temperature control... just see what it takes to get a "stable" temperature and go develop film.

 

[David A. Goldfarb]

Where I live, cold tap water is pretty consistently 72F and ambient temperature in the darkroom is 75-85F depending on the season. I just work with that, but then I haven’t done color for years.

 

[focus_on_infinity]

OK. Cool. Good to see what the, uh, temperature is on this subject.

Yeah, it'll definitely depend on room temperature. Humidity also plays a part, due to evaporative cooling. For instance, if I leave a water bath out, it'll get at least a few degrees lower than room temperature fairly rapidly due to the large surface area and humidity. Maybe not such a factor in a closed development tank. I'll take a few before and after measurements to see how much it's really drifting.

For those of you who are compensating for temperature, would you say that you're altering your development times similarly to the below chart, as provided by Ilford?

 

[MattKing]

For those of you who are compensating for temperature, would you say that you're altering your development times similarly to the below chart, as provided by Ilford?

I use the "calculator dial" in the Kodak Darkroom Dataguides.
Which essentially does the same thing as the Ilford chart, but is more fun .

 

[Bill Burk]

Yes! That’s a great chart. The compensating timers sort of have that built in

 

[mklw1954]

I develop b&w the same way I develop C41, just 68F/20C for b&w. I bring the empty tank containing the reels and film up or down to the developer temperature in a small cooler, using a digital thermometer with a probe to measure the cooler water temperature. When the cooler water temperature is constant at the developer temperature (adding small amounts of hotter or cooler water to the cooler to get there), I start the process, after bringing the chemicals to temperature separately. Bringing the empty tank to temperature takes about 20 minutes but I'm filtering and bringing the chemicals to temperature during that time. Between agitations I put the tank back in the cooler. It's most important for the developer but I do it through the whole process. This is simple but results in improved consistency. There's no concern about the room temperature being different from 68F in winter and summer. Producing consistent negatives makes wet printing much easier.

 

[Arklatexian]

I notice that in almost all videos on developing I've seen, and all tutorials, there doesn't seem to be any temperature maintenence once the developer is in the tank. i.e. other than agitation, the tank just sits there. I haven't yet seen someone set the tank into a water bath to hold temperature.

And while one may adjust one's processess accordingly for B&W, it seems like it just might be good practice if one also does or intends to do C41 or E6.

What say you? A good idea or not?

I say do as I try to do. Keep where you develop film as close to 68F/20C or whatever you develop at as possible, if you shoot and develop BW film. Keep chemicals, and water to dilute them with, in that room. A darkroom is the easiest with that. Then, use as much of the "tempered" chemical/water as the tank will hold. If you can't do all this, use the tempered water bath as you mentioned. They are expensive but a Jobo makes life easier with temperature control................Regards!

 

[pentaxuser]

The developing tank containing the film is then left to float in the top half of the water bath which is still at the temp it was when filled. The power is switched on and left to raise the temperature up to the correct temp of 38C. As the temp rises this will slowly heat the tank to the same level as the chemistry. .

Sounds like a good and straightforward way. My only concern is the floating tank with film in it. Is there no danger that if it is truly floating it remains stable and unlikely to tip up. How deep into the water does the tank sink? In so ways the deeper the better as that adds to stability but on the other hand it brings the water level closer to the top of the tank

I may be concerned here for a death I will never die as the saying but I take it you have never has a problem with the tank tipping?

Thanks

pentaxuser

 

[koraks]

My only concern is the floating tank with film in it.

Put something heavy on top. A jug of water for example.

 

[Agulliver]

I do most of my film developing in the bathroom, which isn't always heated....my photo chemicals generally live in a bucket in the porch (also unheated) but in winter I bring them indoors so they're rarely under 17C. I'll ensure the entire bucket is up at around 20C before beginning my development. I don't feel any need to monitor the temperature even when pushing and using longer times up to 20 minutes. I doubt my developer loses more than 1C during the processing and in the grand scheme of things a minute in 15-20 minutes isn't significant. On shorter processing times such as Fomapan 100 at box speed, the developer really doesn't change temperature much.

It's also generally true that B&W temperatures and times aren't as critical as colour. a 1C temperature change or 30 second slip in E6 or C41 will show....B&W it probably won't unless you have the most critical eye or your negs weren't exposed properly to begin with.

 

[Sirius Glass]

I notice that in almost all videos on developing I've seen, and all tutorials, there doesn't seem to be any temperature maintenence once the developer is in the tank. i.e. other than agitation, the tank just sits there. I haven't yet seen someone set the tank into a water bath to hold temperature.

And while one may adjust one's processess accordingly for B&W, it seems like it just might be good practice if one also does or intends to do C41 or E6.

What say you? A good idea or not?

For black & white I have not used a water bath when processing even in the Jobo processor. For color I always use a water bath.

 

[focus_on_infinity]

OK, so, for a 75F bath (the correct temperature for my developer), I find that after 5 1/2 minutes, it has cooled by 1F. So, unlikely to be an issue for similar temperatures and chemistry. I'm sure it'll be a different situation for color, but I'll let the science speak for itself on that one, also.

 

[Juan Valdenebro]

I notice that in almost all videos on developing I've seen, and all tutorials, there doesn't seem to be any temperature maintenence once the developer is in the tank. i.e. other than agitation, the tank just sits there. I haven't yet seen someone set the tank into a water bath to hold temperature.

And while one may adjust one's processess accordingly for B&W, it seems like it just might be good practice if one also does or intends to do C41 or E6.

What say you? A good idea or not?

A good idea in both cases... And a must IMO for both color and B&W pushing for wet printing, or tone can go crazy very easily... Worse in summer... Big plastic bowls (instead of metal ones) with water surrounding the tank, help to keep temperature close to perfect... A few ice cubes or a jar with hot water make it very easy...

 

[Juan Valdenebro]

OK, so, for a 75F bath (the correct temperature for my developer), I find that after 5 1/2 minutes, it has cooled by 1F. So, unlikely to be an issue for similar temperatures and chemistry. I'm sure it'll be a different situation for color, but I'll let the science speak for itself on that one, also.

Yes, that's close to nothing for well exposed black and white film.