Planning film test exposures

Each filmtests should have ten main exposures.
The ten exposures are divided into 5 exposures bracketed to test for film speed and 5 exposures bracketed to test for film development. Film speed must be confirmed for each test. Film speed will actually drift a bit when development is changed. Even concurrent tests for the same development must be tested and checked for film speed. A film test cannot be accepted until both the film speed target zone (Zone 1) and development target zone (usually Zone 8) have the correct density.

For the sets of five bracketed exposures, shoot in 1/3 increments with the target exposure being the middle exposure of the range. After much trial and error a rather unexpected series of exposure shifts has proven to be readily repeatable and quick to accomplish. Look at the example set of exposures, note that the middle exposure is the one that is anticipated as producing the correct density. The progression is labeled 'linear' only because it starts with the exposure that lets in the most light and progressively reduces the amount of light striking the film:

The following set uses the same f-stop and
shutter speed combinations but made in a different
order:

The second example has advantages over the first. The next page will look at
the advantages and also the question of whether or not
shutter speeds are dependably accurate.