Sony alpha HVL-MT24AM Mode D'emploi page 29

Selecting the aperture when using other than ISO 100, or
when using the wide panel or diffuser
1 Check the calculated acceptable aperture range under the same
condition with ISO 100 by using the table on page 27.
2 Check the additional adjustment when using other than ISO 100 or
when using the wide panel or diffuser by using the table on page 28.
3 Check the calculated acceptable aperture range by using the f/stop scale
using the results of step1 and step2.
4 Apply the result of step3 to the actual aperture range for this particular
lens and select the usable range for satisfactorily results.
Example: Using a 50mm F2.8 Macro lens, two twin flash units, no arm,
magnification ratio of 1:2, and ISO 200
1 Check the calculated acceptable aperture range when using a 50mm F2.8 Macro
lens, two twin flash units, no arm, magnification ratio of 1:2, and ISO 100.
f/8 - f/180 (refer to the table on page 27)
2 Check the additional adjustment when using ISO 200 and diffuser by using the
table on page 28.
Increase the aperture by +1.5 stops (refer to the table on page 28).
3 The aperture increased by +1.5 stops from f/8 is equal to f/4.5, and the aperture
increased by +1.5 stops from f/180 is equal to f/108.
4 The actual aperture range for a 50mm F2.8 Macro lens is f/2.8 - f/32, so the
upper limit of the adjusted f/4.5 - f/108 range, i.e. f/108, is beyond the range that
can be set. The usable range for satisfactorily results is therefore f/4.5 - f/32.