Exposure Meter Ring Range; Working Diagram Of Exposure Meter - Leica R 6.2 User Manual

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Range of exposure meter
In integral mode the exposure meter has a
range from 0.063 cd/m2 at f/stop 1.4 to
125000 cd/m2 (candela per square meter) at
f/stop 22.
For ISO 100/21° film this is equal to the
standard exposure values Ev -1 to +20, i.e.
1
from 4s at f/1.4 to /
2000
In selective mode, its range is from 0.25
2
cd/m at f/1.4 to 125000 cd/m
100/21° film, this is equal to the standard
exposure values Ev +1 to +20 at f/1.4, or 1s
to '/ s at f/22. The diagram on page 16
2000
gives all necessary data for the exposure-
metering system of the LEICA R6.2, such
as sensitivity and range.
Working diagram of the exposure meter
The diagram shows the relationship bet-
ween film speed Sv and brightness Bv on
the one hand, and between shutter-speed TV
and aperture Av on the other, together with
the resulting exposure value Ev. The
diagram is in two parts connected by dia-
gonal lines that represent the exposure value
Ev. On the right, you will find the
brightness value Bv determined by the
exposure meter. The adjacent grey wedges
s at f/22.
2
. For ISO
indicate the working range of the exposure
meter in selective ( ) and large-field inte-
gral ( ) modes. The film speeds Sv are
marked across the top.
The left side of the diagram shows the
camera's working range. In the column of
shutter speeds TV, the long-time exposure
range from 1 s to 60 s is overprinted on a
grey screen. The aperture range (Av) is
marked in the footnote along the base.
A typical example marked in red, shows
how these values correlate. Assuming a film
speed of ISO 400/27°, follow the vertical
line to the point where it intersects with the
horizontal line for brightness, in the case 0.5
2
cd/m , typical for night-time photography.
The diagonal which passes through this
point of intersection leads to the relevant
exposure value, in this case Ev 5. Various
combinations of aperture and shutter speed
can produce this value. For
exposure, the points of intersection of the
vertical Av and the horizontal TV lines
must always lie exactly on a diagonal Ev
line. In the example, three such combi-
nations are shown: A = stop 1,4 at 1/15 s;
B = stop 2,8 at 1/4 s; and C = stop 16 at 8s.
12
correct