JVC LT-19DK8WJ Instructions Manual page 18

Basic operations (Remote control)
• The Full Square mode cannot be
selected with the ZOOM button. It can
only be selected by changing the
Aspect Ratio setting in the Feature
menu.
• The ZOOM mode may be
automatically changed by the control
signal from an external device. When
you want to return to the previous
ZOOM mode, choose the ZOOM
mode again.
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