Technical data

96
Exposure metering
On the LEICA M7 exposure metering uses the
available ambient light selectively through the
lens at the working aperture. The reading uses
light reflected from a bright metering field onto a
photo diode (arrow). This diode is located behind
a collecting lens to the left of and above the shut-
ter. The metering field (diameter:12mm, i.e. ap-
prox.13% of the negative’s size) is situated in the
center of the first shutter curtain. The unevenness
of the white is not a result of poor manufacturing
tolerances, but is due to the fact that a thick, com-
plete coating cannot be applied to the rubberised
cloth shutter curtain without the shutter perform-
ance being impaired.
The irregular structure of the metering field in no
ways affects the meter reading.
The viewfinder displays show or help to determine
the appropriate speed/aperture combination for
correct exposure: When using the aperture priori-
ty mode, the aperture is selected manually, while
the camera automatically calculates the ap-
propriate shutter speed. In this mode, a digital
LED display provides information on the resulting
shutter speed (e.g.
11000000
).
For manual setting of both values, a light balance
consisting of three red LEDs () is used to
balance the exposure. When the setting is correct,
only the central, circular LED is lit.
Switching on the exposure meter
The exposure meter is turned on by lightly press-
ing the shutter release button (9) to its first pres-
sure point, assuming that the camera is turned on
with the main switch (8), the shutter is fully
cocked and the shutter speed dial (12) is not set
to "B”.
Constant illumination of one of the displays in the
viewfinder indicates that the exposure meter is
ready for use:
- the digital shutter speed LED display for aper-
ture priority mode
- one of the two triangular LEDs, possibly com-
bined with the central circular LED, for manual
setting.