Meter Coupling Range - Canon AT-1 Instructions Manual

Meter Coupling Range
If the circular aperture needle does not
align with the meter needle by turning the
aperture ring, it means that the shutter speed
is not properly set. If this is the case, reset
shutter speed dial so that two needles can be
aligned with each other. And when these two
needles cannot be aligned with each other by
turning the shutter speed dial, change the
aperture. When the shutter speed is set a t a
slow speed outside the meter coupling range,
metering cannot be performed even if the
aperture is changed.
The built-in exposure meter couples to
the range of the aperture and shutter speed
with respect to the film speed. For example,
when using the FD 50mm f11.4 S.S.C. lens
and ASA 100 film, the exposure meter
couples within the range of from EV 3 (f11.4
at 114 sec.) to EV 17 (f116 at 1 1500 sec.).
Shutter Speed