I'd echo most of what has been written but I don't have a lift and have found no difficulties. The usual recommendation is to start the timer immediately on pouring in the developer and allow 10 seconds for emprtying at the end. The recommended timing of 3 mins 15 secs allows for this 10 seconds emptying.
Originally Posted by stanley
I know my timing has been a few seconds out on occasions and I haven't found it to affect the film development.
If you can use a hot/cold water mixture from the taps then it is possible to ensure that the water bath in the JOBO is within a degree or two of the right temperature by the time the bath is full. So it shouldn't take long to get the developer and blix up to the right temperature. To speed things up even more place the developer bottle into a container with water at say 45 degrees C and put the thermometer into the developer and monitor it constantly, removing it once it is at the right temp then transfer to the JOBO.
My JOBO temp dial is very accurate and setting it to 38 ensures that the two JOBO thermometers at either end of the bath will read 38. Usually I set to 38.5 to allow for a little decrease when pouring into the dev tank and the 3 mins 15 secs rotation.
Remember that the dev drum is rotating over the water bath and will lose very little temperature over 3 mins 15 secs. If you are concerned to ensure absolute accuracy then test by pouring water at 38 degrees into the tank, rotate for 3 mins 15 secs and then test temperature at end to check on the decrease. Use this test to determine water bath temperature compensation.
Don't worry about stop bath, if you use stop, or blix temp. They are not as critical temperature wise or time wise and anyway if developer temp is correct then as these are both in the same water bath they will be the same temp.