Zone Exposure Calculator
Aperture Setting =
Shutter Speed =
Initial EV =
View Zone Tones
Zone Placement =
Zone Setting Adjustment
Exposure Priority = 1
Shutter Speed =
Adjusted EV =
-/+ Change =
"The Zone System is a photographic technique for determining optimal film exposure and development, formulated by Ansel Adams and Fred Archer."
- [https://en.wikipedia.org/wiki/Zone_System | Wikipedia]
This program is for people who are already familiar with the zone system. Explaining how the zone system works is beyond this description. A quick search online will educate anyone interested in learning about the zone system.
One can input a meter setting and obtain alternate settings, based on a zone preference. It is similar to the old paper wheels that did the same thing. The aperture and shutter settings are limited to the most popular ones found on cameras.
Contributed by Henry Chavez
Take a meter reading of a shadow area in a scene to photograph. Generally, you want the shadow detail to fall on zone III. Let us say your camera indicates f/8 @ 1/125 for the shadow area metered. Enter these two setting in the first two fields. In the next section, select aperture priority and zone III. Selecting aperture priority, locks the initial aperture setting in place and the program only adjusts the shutter speed. In this case it returns f/8 @ 1/500. You can select shutter priority to lock the shutter speed and the program will adjust the aperture setting.
Also, note that you can take a meter reading of a white or black area in your scene and set the zone appropriately. For example, a white rock with some detail could be set to zone VI or VII, depending on the amount of detail you want to record on your negative.
stptbl = [[0.000125; 1] ; [0.00025; 2] ; [0.0005; 3] ; [0.001; 4] ; [0.002; 5] ; [0.004; 6] ; [0.008; 7] ; [0.0166666667; 8]; [0.0333333333; 9] ; [0.0666666667; 10] ; [0.125; 11] ; [0.25; 12] ; [0.5; 13] ; [1; 14] ; [2; 15] ; [4; 16] ; [8; 17]; [15; 18] ; [30; 19]]
apttbl = [ ; [1.4] ; [2.0] ; [2.8] ; [4.0] ; [5.6];  ; ;  ; ; ]