Canon DC-4381 - Manual (Page 19)

EN-19
In the following cases:
Important:
When the keystone adjustment is carried out, the adjustment value is indicated. Note
that this value doesn’t mean a projection angle.
The allowable range of the adjustment value in the keystone adjustment varies
depending on the installation conditions.
When the keystone adjustment takes effect, the resolution decreases. In addition,
stripes may appear or straight lines may bend in images with complicated patterns.
They are not due to product malfunctions.
Noise may appear on the screen during the keystone adjustment because of the
type of the video signal being projected and the setting values of the keystone
adjustment. In such cases, set the keystone adjustment values in the range where
the image is displayed without noise.
When the keystone adjustment is carried out, the image may not be displayed
correctly because of the type of input signal.
Press the Keystone S. Press the Keystone T .