CPE without lift - timing

[nickc1]

I'm starting to use a JOBO CPE2 (without a lift) for C41 processing. I am not

certain about timing the developer. As I see it after I have the system up to

temperature, with the film in the drum, I stop the machine, take the tank off

the magnet and pour in the 240ml of solution - but this will not cover the

entire film, so as quick as possible I put the tank back onto the magnet and

start the motor. About 15 secs before the end of the processing time I stop the

motor and pour out the chemical.

Is this accurate enough?, as as far as I can see it it could be up to 30

seconds before all parts of the film have contact with the developer at the

start of the process, and almost as much delay in pouring out at the end.

It doe not seem tight enough for time, or am I panicing unnecessarily?

[frank.schifano]

Well, how do the negatives look? Do they exhibit noticeable color shifts? Is the contrast too high? Do they appear to be overly dense? If you answer no to these questions, you're on the right track. If yes to any, then some adjustments are in order.

[richard f harris]

Nick,

Consistency is your answer. Find a regime that works and then stick to it. I heat my bath to 38.6C and the chemicals to 38.3C both to within +/- 0.1C. This is not easy with a CPE2 because the thermostat is not that sensitive and the water in the bath tends to have a very inconsistent temperature when measured in different places. I have a small fountain pump in my CPE to move the water around. This gives a consistent temperature accross the bath but; the thermostat has a massive temperature swing between switch on and off, as much as 1.5C which is no use for C41. I altered my CPE by inserting a 400w lighting dimmer in to the heating circuit. Now when the bath is up to 38.6C it switches to power through the dimmer switch. I find that when about half on, the water bath gains or loses heat so controlably that I can maintain the temperature to within the +/- 0.1C that I think is vital for consistent C41 and or E6 processing. I have to say that before I carried out the modifications to the Jobo CPE I think it was close to unuseable for film processing, others may disagree?

Incidently don,t switch off the motor hold and turn the drum in the oposite direction to the motor rotation and it will disengage cleanly without straining the motor or the shaft. I allow 15 seconds for draining and even 20 seconds if using a bigger drum, aim to be pouring in the next chemical at the end of the time allowed for the stage, ie 3:15 for the developer. Pour in as quick as possible and reconnect the drum to the running motor, hit the clock timer button. Prewash with tempered water at 38.3C for 2 minutes and develop for the chosen time. I use 3:05 not 3:15 but you will find the time that gives you the negative density and contrast you want to print with. The further stages stop, bleach, fix and wash are not very temperature critical and you can let the Jobo temperature wander within the control of the machines own thermostat. GOOD LUCK and don't expect to get it bang on first time. It really is easy once mastered.

[nickc1]

Thanks guys.

[golden]

I also have a cpe 2 without a lift, i have been processing e6 with it, i was kind of nervous at first, but i changed chemicals as fast as possible and my results were fine. here is an example<div></div>