Zonemaster II calibration question

[Dave Krueger]

I've been using the Zonemaster II for a couple years and am pretty familiar with the full calibration process, but I now want to do a quick approximate calibration based only on the paper data sheet. The process is pretty straight forward and simple, but I'm confused by a table on the last page of the ZoneMaster II Calibration Manual.

You can see it here at the top left (Page 12, step 5):
Dead Link Removed

As you can see, no correction is required for ISO 200 paper, but +9 steps of correction are required for ISO 100. Since the exposure values in the Zonemaster are adjusted in 1/12 stop increments and the difference between ISO 200 and 100 is a full stop, shouldn't the correction factor be +12 instead of +9?

 

[ic-racer]

Perhaps if the calibration method was based on ISO speed. Is it?

 

[Dave Krueger]

Perhaps if the calibration method was based on ISO speed. Is it?

Exposure correction factors are entered in increments of 1/12 stop. See page 6, step 3. The difference between ISO 100 and 200 is 1 stop. That should be 12 steps.