Quote Originally Posted by Nicholas Lindan View Post
Have you tried a timer dial? I used one for a day just to see what it was like, and thought it a better solution than a chart.

Progressive stop-interval test strips were a PITA, and I went back to using seconds.

For burns and dodges I either used the difference in seconds between stops tick marks or for very simple cases did the burn live, to burn 1.5 stops over 3.0 stops: set the timer to 4.5 stops; place the burning card; start the timer; remove the card when the timer had wound down to 3.0 stops.

http://www.darkroomautomation.com/support/grastops.pdf
When I see a print that needs some corrections, I think f stops. I guess it's a carryover from camera practice. Sometimes I even make adjustments that way, but more often I change the time. It's pretty easy to convert in your head and at least get in the ball park. (A third of a stop is 25 percent more or 20 percent less; two-thirds is 60 percent more or 36 percent less.)