Zone System calculator
Your meter always reads Zone V, a mid grey. Pick the zone you actually want that reading to fall on, and get the corrected exposure. Each zone is one stop.
Rule of thumb: place your darkest important shadow detail on Zone III, then develop for the highlights.
About this tool
The Zone System places a metered tone onto a chosen brightness zone, from deep black at Zone I to bright white at Zone IX, with the meter reading Zone V mid-grey. This tool takes your metered shutter and aperture plus the zone you want a subject to fall on, then returns the corrected exposure. Each zone equals one stop, giving you precise tonal control.
How to use it
- Meter directly off the tone you care about and enter that shutter and aperture.
- Choose the zone you want that tone to render on, from I to IX.
- Read the corrected exposure the tool calculates.
- Set the adjusted shutter or aperture, opening up above Zone V and closing down below it.
FAQ
Why does the meter read Zone V?
A reflective meter renders whatever it reads as mid-grey, which is Zone V. To place a tone higher or lower you add or subtract stops from that reading.
How many stops per zone?
Exactly one stop. Placing a subject on Zone VII instead of Zone V means opening up two stops so it renders as light grey rather than mid-grey.