Film Processing Temperature Control

[K_Wong]

Advertisement (gone after registration)

Hello everyone. This is my first thread here

 

In the process of film processing, I understand that the temperature control is very important, but I do not fully understand about the details about it.

 

First of all, do i have to make sure the chemicals is at the right temperature, or is it just the mixture's temperature that I have to worry about?

 

Secondly, if it is just the mixture that I have to worry about, how do i make sure the mixture stay at the same temperature throughout the processing in the developing tank? Especially when the summer (currently based in Australia) is getting near, it is harder to just use the room temperature and develop, hoping for the outcome to be acceptable.

 

If the temperature is crucial, is there any equipment that I can use to maintain the temperature or use the waterbath technique that I heard (dipping the developing tank in water and monitoring the water temperature ) ?

 

For what it's worth, I'm usually dealing with Kodak Tri-X 400, developing using the R09 One Shot developer.

 

Any information would be greatly appreciated.

[davidmknoble]

Temperature is important and is also one of the most difficult things to control. However, probably most important is taking accurate temperature readings and accurate development times with proper agitation per the developer instructions.

 

Like it or not, the chemicals are room temperature. The water is what it is and the two mixed together will produce a given temperature. Developer is the most important of the temperatures, so mix and take a reading. The rule of thumb I use is that I would like at least 7 minutes of development time. Less than that means the shadows are a little less fully developed. In addition, the closer to 68 degrees F everything is, typically the tighter the grain (may not be scientific, but my experience anyway).

 

So, what is in your control? Well, the mixture is. If the time is too short for the given temperature, then can you dilute the developer and get a longer time. So, if your developer is 1:4, can you determine the proper time for, say, 1:10? You have to really read the developer details from the web site.

 

I use the Illford liquid developers and rapid-fixes with Kodak stop bath and third party rinse aids. I shoot mostly Illford films although I have taken a real liking to Fuji Acros 100, which I shoot at ISO 70 in my MP. Then I scan it with a Nikon film scanner into Lightroom.....

 

Hope this helps!

[Advertisement]

The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[miha]

Hi, the temperature should be strictly controlled if quality and repeatable results are what you strive for. If your developing times are below 10 minutes, then it's not too difficult to maintain you processing temperature within one degree.

 

If you are using plastic tanks (Paterson, Jobo), then the tanks themselves will maintain the temperature well within the range as plastic is an insulator. If you are using SS tanks (Nikor, Kindermann,..) then it's wise to temper them in a water bath (in a plastic tray/bucket,..) as steel is conductive enough so that you can regulate the temperature of the developer in the tank with a water bath - use some ice / hot water.

 

BTW, you can easily develop at say 24C if 20C is too inconvenient.

 

Good luck!

Edited October 15, 2014 by miha

[Leicanerd]

Also, you can put developing tank and measuring cups in a water bath and cool it down with rigid ice packs.

[Doc Henry]

Wong, welcome to LUF !

Constant temperature (for 5 mins) is more important for the color (C41 development) but in black and white around 20 ° C is good .

Cold tap water is usually around 20 °, no need for a water bath for 7mns TX

Best

Henry

Some pictures for color devt home (Tetenal 5mns 30°C )

http://www.l-camera-forum.com/leica-forum/street-photography/346868-london.html

and for b&w , also devt home (example post 1755)

http://www.l-camera-forum.com/leica-forum/other/286747-i-like-film-open-thread-88.html

or here

http://www.l-camera-forum.com/leica-forum/people/349045-glances-complicity.html

Please post your pictures on "I like film" thread. Thanks

Edited October 15, 2014 by Doc Henry

[Paulus]

Our cold tap water is mostly around 17 degrees. I warm the developer fluid in the bottle "au bain marie" till 20 degrees. The stop and fix I do not warm. 6-7 minutes Tmax developer ( every 4 films a minute longer ) and the negative is fine to me. It;s only 7 minutes so I do not keep the temperature steady. All the agitating with my hands will ad as much heat as what it will cool down I suppose.

[adan]

Advertisement (gone after registration)

For B&W film, a specific developing temperature is not required, so long as it is not outrageously far from the norm (20 degrees C). The reaction speeds up at warmer termperatures, (and is slower in cooler temperatures) so one simply needs a time/temperature table or scale to choose a different (shorter) time for warmer chemicals.

 

Something like this: http://www.digitaltruth.com/gfx/time.gif

 

Simply find the correct time at 20 C for your film and developer, and then follow the reference line (diagonals) from that point on the chart to your actual available temperature.

 

E.G. on that chart - if the box-recommended development is 12 minutes at 20 C, and your actual developer is at 24 C, simply follow the diagonal line from 20 C/12 minutes up and to the left until it crosses the 24 C line, and read off your time to develop at 24 C (on that chart, 8 minutes, 10 seconds).

 

Steps following development (stop, fix, wash aids, water wash) are not as temperature-critical as development, since they are done "to completion". E.G. you want to fix away ALL the remaining unexposed/undeveloped silver, so a few extra minutes in the fixer (or slightly warmer fixer) is just not an issue.

 

- with the following cautions:

 

Widely different chemical temperatures across the processing steps can increase film graininess.

 

Going from warm chemicals into cold chemicals/water can cause reticulation (wrinkling of the gelatin) - so if there must be variation, make sure the temps increase as you go through the processing steps (i.e. avoid warm developer and cold stop bath).

 

Avoid development times under 4 minutes - you risk uneven development.

 

The usual range for B&W film processing can be 18C to 25 C. Colder than that, the fixer starts to become very slow and ineffective, and warmer than that and you get either ridiculously short times, or risk softening the gelatin, making it far more subject to scratches, etc.

____________

 

Color processing is more stringent for development (+/- 0.25 degrees, 100 degrees F, 3:15 minutes Kodak Flexicolor) because the developer has to penetrate different gelatin layers for the different colors, and any variation will lead to one layer or another getting too much or too little development and color cross-overs. That specific time/temperature accounts exactly for the absorption rate of the gelatin.

 

But even with color, the downstream processing steps have some leeway in temperature (bleach and fix can be from 4:20 to 6 minutes, and +/- 5 degrees F, according to my Kodak C-41 instructions - longer times if below 100F, shorter times if above 100F).

Edited October 15, 2014 by adan

[tobey bilek]

Soak loaded tanks, chemicals, in a water bath. Leave a thermometer in the bath

and use hot water or ice to adjust as it changes to ambient temp. Check developer temp with a dial thermometer and when ready add to tank.

 

If the tank is not stabilized , the tank will cool or warm the incoming liquid.

 

You can force rapid change if a dial thermometer is placed in the chem and either very hot or very cold is used to adjust only to close to required temp. Then use the water bath to finish.

 

Glass containers are best or stainless as heat transfer is easy, Plastic is an insulator.

[K_Wong]

Thanks to all who have responded so far. The insights shared are very interesting and helpful.

 

I guess I would just need more experience in processing films!

[Herr Barnack]

I have always used a warm water bath to keep the temperatures of my chemistry constant - I have never had any problems using this method, even in developing E-6 film which is the most temperature sensitive.

 

The early stages of developing are the most critical - the chemistry instructions will indicate this. As you progress in the developing sequence, you have more latitude temperature wise.

 

If overeating your chems is a concern where you are located, a cool water bath using a blue ice cooler pack like you put in a cooler to keep beer cold should work.

[CalArts 99]

In addition to Andy's sound advice, you might want to consider using Diafine if you feel that temperature control will be difficult for you to maintain. I use it exclusively with certain films (e.g., with a stash of Plus-X I have which I expose at 400 ISO in Diafine.) Not only is it tolerant of temperature, but also time (it's a two bath compensating developer that's very simple to use.) It also has a very long shelf life once mixed for a working solution. And it produces negatives that are perfect for scanning.

 

It's great with Tri-X, the film you mentioned you use often. Here's some info and some images by a Leica user who uses Tri-X in Diafine: Film Testing Kodak 400TX and Diafine Developer | The Figital Revolution

 

And here's an overview of Diafine: Diafine – A Black and White Film Developer | Analog Film Photography