Exposure Metering Diagram - Leica R9 Instructions Manual

Exposure meter diagram
The following diagram shows the relationships
between film speed (SV = speed value) and light
intensity/brightness (BV = brightness value) on
the one hand and between exposure time (TV =
time value) and aperture (AV = aperture value)
on the other, each with the resulting exposure
value (EV = exposure value). The two parts of the
diagram used are brought together by the diago-
nal lines corresponding to the EV values.
An example (dotted line) shows the relations of
the individual values to one another. From the set
film speed (here: ISO 100/21°), you can follow
the vertical line to its intersection with the hori-
zontal line for the given light intensity (here:
2
2 000 cd/m ). The diagonal line running through
this intersection leads to the corresponding
exposure value (EV 14). This EV value can be
translated into different aperture and shutter
speed combinations, i.e. it can be transposed
into the camera's working range.
The intersections of the vertical AV and horizon-
tal TV lines must be on the diagonal EV lines in
order for the exposure to be correct, e.g. f/16
and 1/60 s (case A) or f/8 and 1/250 s (case B)
or f/4 with 1/1 000 s (case C). Each of these
combinations would result in correct exposure.
In aperture and shutter speed priority modes,
one of these values is selected and the second is
set automatically. In automatic program mode,
both values are set automatically.
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