Acer P211 User Manual page 23

Chapter 3
Hor. Position adjusts the horizontal position of the display.
Hor. Size adjusts the width of the display.
Ver. Position adjusts the vertical position of the display.
Ver. Size adjusts the vertical height of the display.
Geometry
Advanced geometry adjustments
Pincushion controls the straightness of the vertical edges of the display.
Unbalance adjusts balance when the sides of display are bowed
towards left or right
Trapezoid makes the vertical edges of the display parallel.
Parallelogram corrects image leaning left or right.
Rotation corrects screen tilt.
Top Corner adjusts the edges on the top corners of the screen image.
Bottom Corner adjusts the edges on the bottom corners of the screen
image.
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