yes an adjustment of the starting temp equal to plus half the total delta T would be the way to go. But since I used constant agitaion and they recommended that would give higher contrast ( I read that as more development) I decided to go with 85 deg starting temp. and it worked so well I never risked messing with my process procedures. It could be the drift is minor, I don’t really know. I guess I will do some tests just to be sure nothing really crazy is going on....
the process instructions with the chemistry did not specify constant or intermittant agitation ( BAD OMMISSION !) so I just assumed with a 10 minute time intermittant agitaion would be fine since I remembered that intermittant was OK with BW fixing... JCO -----Original Message----- From: William Robb [mailto:[EMAIL PROTECTED] Sent: Monday, January 17, 2005 11:55 AM To: pentax-discuss@pdml.net Subject: Re: Decisions...Decisions... ----- Original Message ----- From: "J. C. O'Connell" Subject: RE: Decisions...Decisions... > One of the beauties of using 85 deg processing is that since it is > only about 12 degrees above room temperture, there is much less drift > in the process temp vs. time in an untempered process. With 100 deg > processing the drift would be much more of a problem. A good point to bring into the discussion is more on temperature drift. Back in the dark ages, if we wanted to hit a median temperature of (eg:)85ºF, we would measure how much the temperature of an untempered tank drifts down during the development cycle, halve that number and increase the starting temp by that amount. In practice, if the drift over 6.5 minutes is 8ºf, then the tank temperature to start would be raised to 89ºF. This completely obviates the need for any temperature control, providing the temperature drift is reasonable. > The only "trick" is I built the intermittant agitation > timer myself which is a timed relay to turn motor on only > 5 seconds out of every 30 seconds. But I think you could > do second step with constant agitation too with same results so > intermittant roller timer really isnt necessary... You can use constant agititation during blix and wash as well. William Robb
