A number of years ago I developed my own C41 films using a Unicolor film drum. My daughter now wants to try it. I seem to remember that there was a "drift by nomograph" available which took into account the temperature to which the chemicals should be heated versus room temperature and time of development.

Am I having a senior moment? If not, can someone please direct me to this nomograph.

TIA,

George

I don't have the film drum (wish I did), but have said nomographs for old paper tubes.

What about a 'dry' run to fugure the required parameters?. The thermal load of the film itself is insignificant. Load the drum with the reels or film holders as you will use it, and run a few water batches. Measure the temperatures in and out, and then work out the average for the ambient room temperature that you are operating in.

There will be a slightly faster heat loss if you need to go to a hotter start temp to get the correct drift by average to work out the right temperature for the 3:15 or so that the developer stays in the drum, if your first water only run gives too low an average temperuture.

Somewhere in the UK I have a similar Paterson calculator that does the same for colour prints. However I've never found a need to use anything like that for film processing. The C41 process is short and the dev stage temperature is easy to keep stable with a simple water bath.

Ian

Mike & Ian,

Thank you for your input.

George