View Full Version : How to develop B&W film (HP4 100) with No Thermometer

3-Dec-2017, 16:41
Yesterday I took some lovely 4x5 shots in B&W but when I went to develop them I couldn't and still cant find my thermometer for the chemicals...............I went and bought two yesterday in Phuket town but when I got home found that the digital and the analog one don't start recording until 35 degrees...........what can I do now as I want to develop them today.
Ambiant temperatures in Phuket range between 28 to 32 degrees............ Im guessing but I would say my fridge is at around 15 degrees


Jim Jones
3-Dec-2017, 17:14
For many years I tried to maintain the darkroom at a temperature compatible with B&W processing (18-29 degrees C) and stored the chemicals, water, and tanks in it. This was convenient and worked well. The short development times at elevated temperatures does require care. A pre-wash may become necessary for even development. If the darkroom temperature is fairly constant, any fairly reliable thermometer suffices. Consistency is more important than absolute accuracy.

Jerry Bodine
3-Dec-2017, 17:39
This is a long shot; I personally would not risk it unless I were desperate to develop right now. After some online work:

Current time in Phuket ~ 7:30 a.m.
At 12:00 noon OUTSIDE TODAY in Phuket the forecast says it’ll be 29*C (it’s now 26.7*C)

Don't know how outside temp compares to your processing area.

ILFORD’s Time-Temperature Chart for film development:

Did you mean FP4 125 film? If so, here's Ilford's recommendations for normal development:

3-Dec-2017, 18:27
Try some two-part developers. Google it and come back if you have no luck.

John Olsen
3-Dec-2017, 18:58
Don't. It's too risky.

Years ago I was working in a place that had a rental darkroom. The boss's wife came in to develop a roll but declined to take a thermometer when I set up her equipment tray. When the film was ruined I got blamed for not mixing the chemistry correctly. I still shudder when someone suggests doing it without a thermometer.

David Karp
3-Dec-2017, 19:09
You can use a two bath developer, but make sure it is the right kind. Two part Diafine is a two bath developer that is designed to work at any temperature. There is no development in the A bath whatsoever because there is no acceleration (activator) in that bath. The accelerator is in the second bath and development is nearly instantaneous. There are recipes for mix it yourself Diafine on the web. I have never tried one of these.

On the other hand, a two part developer like Divided D-23 has a fully-formed developer in Bath A. Development starts in the first bath. Temperature and time will make a difference with this type of developer.