Calculate Lens Offset - Christie DHD675-E User Manual

3.6

Calculate Lens Offset

The vertical image offset (shift) ranges for the projector are +120%/-40%
y
(WUXGA) and +134%/-40% (HD). Offset is +720 pixels for both WUXGA
and HD. The horizontal image offset is +/-20% (+/- 192 pixels).
NOTE:
The 0.8:1 lens is the only exception and must be used on axis.
™
The method for calculating lens offset complies with Industry standards.
y
Example for Vertical lens offset:
-
At 0% offset (or on axis), the center of the image is on the lens center,
so that half of the image appears above and half appears below the
lens center.
-
At +100% offset, all (or 100%) of the image will appear above the lens
center.
-
The % offset is calculated as the ratio of the number of pixels shifted
up/down to half the image size. Examples for WUXGA:
`
`
`
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WUXGA Projectors:
Vertical Image Offset: 0% Offset (WUXGA)
600 pixels
above lens
center.
600 pixels
below lens
center.
E Series User Manual
020-000515-01 Rev. 2 (03-2013)
Shifting up 600 pixels gives offset of 600/600 * 100% = 100%
Shifting down 600 pixels gives offset of -600/600 * 100% = -100%
Shifting up 720 pixels gives offset of 720/600 * 100% = 120%
Shifting up 240 pixels gives offset of 240/600 * 100% = 40%
No offset is applied - 0% offset.
Half of the image appears above lens center
and half of the image appears below lens
center.
Lens center
Section 3: Installation
3-5