Sorry I didnt make myself clear, I meant marking the strips up semi-permanently, for a set of lenses for the duration of a job. So interchanging between the same set of lenses. I am trying to figure out the best procedure for calibration, do you always set the lens to the same position when initially engaging the motor, do you calibrate only up to the infinity mark and the close focus mark, or do you go right to the end stops, and so on. I want to be confident enough in the procedure to swing a lens, calibrate with a pre-marked strip in place, quick check, and go, rather than re-mark a blank strip.
sorry for the confusion
Rory