Aggitation Compenstation w/Change of Dev Time

[peter k.]

I'm intrigued to maybe try and change my development time, to compensate for the temperature, when I'm actually doing the development. Instead of mixing cool water from the refrigerator, to the standard 68*.. that I have been doing. But if one did this, how does one compensate for agitation?
That variable, from a true and tried development work pattern that has been successful, would seem to me, like playing Russian Roulette!

As and example lets say development time at 68* is 8.5 min, agitation for about 3sec every 30 sec.
Which after initial agitation.. there would be 15 times that the tank is agitated, and not doing an agitation at 8.5 as the developer drained out.
Using Ifords Compensation chart
http://www.ilfordphoto.com/Webfiles/2006210208211880.pdf
@ 75* it would be 6.0 min

One could work the time sequence,, so one could agitate it 15 times within the 6.0min, but wouldn't that blow it away... (become to contrasty and lose the highlights) so how do you compensate, consistently with a temperature change, that may be different later in the day, or on a cooler day or warmer day?

 

[MattKing]

You should leave the length and frequency of the agitation constant. If you agitate 5 seconds in every 30 seconds, just stay with that.

The role of agitation is to remove spent developer (or other chemical) from the surface of the film and replace it with relatively more fresh developer (or other chemical).

The agitation itself doesn't really affect the development, it is the arrival of fresher developer that does.

 

[Gerald C Koch]

Stick with the recommended agitation. The table that you cite is based on using a common agitation method. Excessive agitation can cause surge marks and foaming, neither of which is good. Reduced agitation has its own set of problems, for example bromide drag.

 

[RalphLambrecht]

I'm intrigued to maybe try and change my development time, to compensate for the temperature, when I'm actually doing the development. Instead of mixing cool water from the refrigerator, to the standard 68*.. that I have been doing. But if one did this, how does one compensate for agitation?
That variable, from a true and tried development work pattern that has been successful, would seem to me, like playing Russian Roulette!

As and example lets say development time at 68* is 8.5 min, agitation for about 3sec every 30 sec.
Which after initial agitation.. there would be 15 times that the tank is agitated, and not doing an agitation at 8.5 as the developer drained out.
Using Ifords Compensation chart
http://www.ilfordphoto.com/Webfiles/2006210208211880.pdf
@ 75* it would be 6.0 min

One could work the time sequence,, so one could agitate it 15 times within the 6.0min, but wouldn't that blow it away... (become to contrasty and lose the highlights) so how do you compensate, consistently with a temperature change, that may be different later in the day, or on a cooler day or warmer day?

a basic rule for testing is:never change more than one variable at a time unless you clearly understand the interactions.correcting for tempchanges with devtime works well.I use the Ilford table.I tested the influence of agitation and found it to be of marginal influence.Ialways use the top speed in the Jobo rotation.The slower speed causes uneven development in my caseand a prerinse or not didn't make any difference but had to be a min of 5 min to not cause uneven development,so I dropped that idea.

 

[peter k.]

Well gave it a try today.. first one at 78* and the next @ 82* with same agitation scheme, came out fine... fascinating.. some how I got the idea in developing for the highlights, it was more to the agitation, than to the time of the development.. got that cleared up now!
Doing the development to the temp sure helps when you got just one shot or two your trying out.. instead of getting the temp to 68*and doing all that... thanks...