Canon 312 XL-S - Manual (Page 29)

from a change in focal length caused by rotating the
zooming lever. Zooming is most effectively used for
creating special effects. This camera offers both
power and manual zooming.
Power Zooming
When either power zooming switch is pressed while
pressing the shutter release lever, zooming will
automatically start. When "T” is pressed, the focal
length changes to telephoto making the image
larger. Pressing "W" will change to a shorter focal
length giving a wide-angle view. The former opera­
tion is known as “zoom-up" and the latter as “zoom
back". Zooming time is about 6 seconds. Power
zooming makes zooming quite smooth.
*Be careful not to cover the light metering window
with your hand while power zooming.
Manual Zooming
Manual zooming can be performed with the manual
zooming lever which can easily be rotated with
fingertip. It is generally used to control picture
composition and to control zooming time when you
want slower or faster zooming than that offered by
power zooming. Since the manual zooming lever
doubles as the macro setting lever, don't lift it up or
you will switch to macrocinematography by mis­
take.