Distance Metering; With The Optical Range Finder - Leica M 240 Instructions Manual

EN RANGE MEASUREMENT
Various tools are available for setting the range, depending on
whether you are using the camera's internal optical viewfinder (27)
and/or live view mode (see p. 176).
Notes:
• The electronic displays are based on the image captured by the
sensor. To use it, the shutter must be open and it is closed and
re-cocked when the function is cancelled. Of course, this is
audible and may result in a slight delay in the shutter release,
and also results in increased power consumption if used
frequently.
• Due to the different sensitivities and function conditions, there
may be differences between the optimum settings and those
displayed.
178
With the optical range finder
Due to its large effective metering basis, the range finder on this
camera is very precise. The benefits of this are particularly
noticeable when using wide-angle lenses with their relatively high
depth of field.
Mechanical metering basis
(Distance between the optical
axes of the viewfinder window
and the range finder viewing
window)
69.25mm
The range finder metering field is visible as a bright, sharply defined
rectangle in the center of the viewfinder. The focus can be set
using either the superimposed image or split image method:
x viewfinder = Effective
zoom metering
basis
x 0.68 = approx.
47.1mm