The Zone System

Adams Zone System was based on F/Stops at the time there was only Whole F/Stops, so he found there to be 11 Zones

O

I

II

III

IV

V

VI

VII

VIII

IX

X

the idea was if you take a picture at the same shutter speed but different F/Stop where would it put the zone or shade of black. I've found that you can use the zone system also as a way if you keep the same f/stop but change the whole shutter speed different. now a days we have 1/3 stops and 1/2 stops theory based on new photography hardware is there are more zones than the 11 Adams described, there are 44 zones. show I would give the zones like this

0	1	2	3	4	5	6	7	8	9	10
0.3	1.3	2.3	3.3	4.3	5.3	6.3	7.3	8.3	9.3	10.3
0.5	1.5	2.5	3.5	4.5	5.5	6.5	7.5	8.5	9.5	10.5
0.6	1.6	2.6	3.6	4.6	5.6	6.6	7.6	8.6	9.6	10.6

Now manually chart out the zones based on Adams Zone system we start with the middle being Zone V.
lets start with basic Adams System with a formula with the start of Zone V
Zone V = (whatever the light meter says)

Zone VI = V * (sqrt(2))

Zone VII = V * 2
Zone VIII = V * (sqrt(2))³
Zone IX = V * 4
Zone X = V * (sqrt(2))⁴

Zone IV = V / (sqrt(2))
Zone III = V / 2
Zone II = V / (sqrt(2))³
Zone I = V / 4
Zone O = V / (sqrt(2))⁴


We'll Say Zone V is f/16 so then we can calculate the rest of the f/stops

Zone VI = 22.6
Zone VII = 32
Zone VIII = 45.3
Zone IX = 64
Zone X = 90.5

Zone IV = 11.3
Zone III = 8
Zone II = 5.6
Zone I = 4
Zone O = 2.8


Based on the formula to calculate the different between F/Stops can find what zone different between F/Stops.

F/Stop different = (Log(f1) - Log(f2)) / (Log (sqrt(2)))

Here I've charted out starting at Zone V, then the difference between each zone from Zone V.