Canon T2000 - Manual (Page 25)

crease film consumption
by one third and also calls
for sufficient light due to
the slightly wider aperture
required to make up for
the faster running speed
and shorter effective ex­
posure per frame.
1 2
Please note that you eannot,
of course, alternate be­
tween sound filming
speeds of 18 and 24 fps
because you can use only
one of these speeds for
projection (per reel) to
avoid sound distortion.
The decision which of the
two speeds to use should
therefore be made before
you start filming.