I've got a Rolleiflex E2. On the back of the camera is a chart that has a column showing F-stops. The column is on the left edge of the table and from the top to bottom shows 22, 16, 11, 8 etc. Across the top of the table are the numbers 1 through 8. In the body of the chart or table are time values given in seconds. The numbers 1-8 (light value numbers?) have a small graphic of a knob pointing to them, which looks to be a knob that should be on the camera. But I cannot find any knob that has the values 1-8. I would guess that the whole idea is to obtain a light value of 1 - 8 and then find the corresponding time for whatever f-stop you want to use. Is this correct? And where do you obtain these values? are they EV units and if so, why only 1-8? The only knob that has any such values has (to my understanding) EV values from 4-18 and turning this knob will change the "Sec" value and changing the F-stop on the camera will change the indicator on the EV wheel. I'm just wondering why one would need the chart on the back when one could measure the Exposure Value of the subject using a light meter, turn the f-stop wheel and the time wheel to the various combinations that will give you that EV on the little wheel.