What is BTZS?
BTZS refers to “Beyond The Zone System,” the title of a book Phil Davis wrote
almost 25 years ago, and is now in its 4th edition. This was not an
attempt to discredit Ansel’s work; his Zone System concept was
innovative and ingenious, and his art and technique have inspired
generations of photographers. But times have changed and we now have
tools and materials that were unavailable when the Zone System was
As a result, BTZS is “beyond” the Zone System in several ways.
- First, we
test our materials using sensitometric methods to produce test data that
are more comprehensive and more reliable than conventional empirical
methods can achieve.
- Second, we use sophisticated computer programs to
analyze the test data in the lab, and generate working data in the
- Third, we replace “N-numbers” as indicators of development extent
with Average Gradient values which are more specific and more
- Finally, we recognize that both science and art are
essential elements in photography.
BTZS can equip you with the knowledge
and skill you’ll need to handle your materials effectively, but that’s
as far as it can go; it’s up to the artist in you to apply what you’ve
learned to produce images that are worth looking at.