Grass Valley 1200 Operation Manual - Manual (Page 171)

4-9
Luminance and Linear Keying
Luminance and Linear Keying
Luminance and linear keys enable you to insert one picture into
another to create a composite effect. For example, you may want
to add a caption to a scene (Figure 4-4). For more information
about keying, refer to Section 2: Concepts You’ll Need To Know.
To create a luminance or linear key, do the following:
1. Double press the Keyer [Key 1] , [Key 2] , or [DSK] button to
delegate a keyer and display the Keyer menu.
2. Select a Key bus [crosspoint] to provide the fill video. When
you select a crosspoint, Key Memory automatically recalls the
key type and adjustments last used with that crosspoint.
3. Select [Auto Select Key ] or [Video Key] , as desired.
Selecting [Auto Select Key] creates the key using both the
fill and the source assigned to the crosspoint. Selecting
[Video Key] produces a self key using only the fill video
assigned to the crosspoint.
4. Select [Luma Key] or [Linear Key] . Note that [Luma Key]
is usually used for video self keys, and [Linear Key] is
usually used when keying from anti-aliased graphics,
characters, or digital effects images.
5. If you want to split the key (select a source different from the
one assigned to the selected fill crosspoint), hold down the
[Video Key] or [Auto Select Key] button and select a Key
bus source [crosspoint] . The split source crosspoint lights
when you select it, and lights anytime you hold down [Video
Key] or [Auto Select Key] . To turn off a split key, hold
down the [Video Key] or [Auto Select Key] button, and
reselect the Key bus fill video [crosspoint] .
6. For keying from a black on white source, select Keyer
[Invert] . For keying from a white on black source, leave
[Invert] off.