Christie M Series User Manual page 87

Section 3: Operation
What is a Blend?
In simple terms, a blend appears as a gradient strip along an edge of a
projected image. It is darkest along the extreme edge of the image, and
lightens nearer to the rest of the image (see right).
How Are Blends Used?
In multiple-projector walls, complementary blends between neighboring
images can compensate for the extra "brightness" or intensity where these
edges overlap. By controlling blend width and other properties, you can
achieve uniformity across the group of images. Visible overlaps will
disappear, Figure 3-37 Edge Blending
For best results, use the same projector model
and type throughout your display wall. In
addition, avoid high-gain screens whenever
possible—the optical performance of such
screens demands minimal image offset, thus
projectors must be located very close to one
another.
Edge blending software controls are located in
the two-page Edge Blending submenu—
access via Configuration menu, then go to the
Geometry and Color menu and select Edge
Blending. The Advanced Edge Blending
option opens the second page of the Edge
Blending submenu.
ADVANCED EDGE BLENDING
Use Edge Blending controls to set the precise width, shape and midpoint you need to blend overlapping edges
together smoothly.
• Blend Width determines how much area is used for blending along an overlapping edge. Slide bar values
represent the number of eight-pixel steps used for the blend. For example, a setting of "eight" creates a
blended edge 24 pixels wide.
• A setting of "0" signifies no blending. For best results in most applications, use a blend width of 16-48
steps (128-384 pixels).
• Blend Shape determines the rate of roll-off across the blend width, i.e. how quickly the white levels across
the blend change from light and dark. Increasing the Blend Shape setting accelerates the rate of change at
both extremes so that less of the region appears mid-gray (see Figure 3.20). Decreasing the Blend Shape
setting slows the rate of change so that more of the region appears mid-gray. For most applications, this
subtle control is best left close to 50.
• Blend Midpoint determines the white level at the blend midpoint (the point equidistant between the
beginning and end of the blend). Increasing the Blend Midpoint setting creates a blend that appears brighter
than the rest of the image. Decreasing the Blend Midpoint setting creates a blend that is darker than the rest
of the image. A setting of 50 means the midpoint is approximately 50% black—for best results in most
applications, keep fairly close to this default.
• Show Blending Overlap turns your defined blend width area to solid gray so that, if needed, simply
overlapping the gray bars can seamlessly align two adjacent images. Toggle the Show Blending Overlap off
3-44
Concept:
Ranges: 0-80 horizontal, 0-60 vertical.
NOTE:
F
IGURE
F 3-37 E B
IGURE DGE LENDING
3-36 E B
DGE LENDING
C
ONCEPT
M Series User Manual
020-100009-04 Rev. 1 (10-2009)