User manual

4.0 MENU OPTIONS
R699761 - DreamScaler 4 User Manual 21
The Display Aspect Ratio is the full aspect ratio of the display, normally specified in the display manual. Common
display aspect ratios are 4:3 and 16:9. Less common ones are 5:4, 2.35:1 and others. The example below shows a
16:9 input with a 4:3 screen.
The region outside the Active Output area (called the mask) is inactive, and only important for creating video timing
signals for the display. Input video data is never mapped to this region.
When the Display Aspect Ratio is not the same as Active Output Aspect Ratio, the mask is set to blanking levels
and always centers the position of the active area over the display area.
Image shift
Image shift allows you to adjust the location of the image on your screen both horizontally and vertically when the
‘Screen’ aspect ratio is not equal to the ‘Display’ aspect ratio. The example below shows 16:9 projector (1.78:1) and
a 2.35:1 screen, you can shift the image to match the exact location of your screen. In this situation, the image is
shifted down putting all of the mask at the top of the projected image.
Underscan
Underscan represents the visible display area, a sub-set of the Active Output Area. Underscan is like a negative
zoom which preserves the aspect ratio of the active area. The default for this setting is 0. As you increase
underscan, the smaller portion of the active display area appears while preserving the aspect ratio of the active
display area.
Sync Type
The Sync Type option sets the synchronization signal type of the output format. Press the Up or Down button to
show the current sync type. Press the same button again to move to the next synctype.
Currently, the DreamScaler 4 supports seven sync types: Bi-level, Tri-level, Composite Sync (on the H BNC
connector), H+V+, H+V-, H-V+, H-V-.
Mask
Active Output Area
3
4
9
16
MaskScreen Aspect Ratio
(2.35:1)
Screen Aspect Ratio
(2.35:1)
Image
Active Output