VIEWSONIC A90F+ - Manual (Page 9)

Main Menu Controls
Adjust the menu items shown below by using the up I and down J buttons.
Control Explanation
Contrast adjusts the difference between the image
background (black level) and the foreground (white level).
Brightness adjusts the background black level of the screen
image.
H. Size (Horizontal Size) adjusts width of the screen image.
H. Position (Horizontal Position) moves the screen image
left or right.
V. Size (Vertical Size) adjusts the height of the screen
image.
V. Position (Vertical Position) moves the screen image up
or down.
Zoom expands and contracts the entire screen image.
Pincushion curves the vertical edges of the screen image.
Pin Balance curves the vertical edges of the screen image
to the left or right.