Scheimpflug: Tilted Lens Results In Tilted Focus Plane; Scheimpflug Adjustment Points - Barco Galaxy NH-12 Installation Manual

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Image 3-68
Scheimpflug: tilted lens results in tilted focus plane
In the example above, the top part of the image will be in focus behind the screen, the bottom part will be in focus in front of the
screen. This effect is applicable for left-right tilt of the projection lens as well.
If in practice some areas of the projected image are well focused on the screen, whereas other areas are still out of focus (i.e. the
focus is in front of or behind the screen), we can try to realign the projection lens to adjust the Scheimpflug.
Scheimpflug functionality of the lens holder
Small thin metal plates can be mounted on (or removed from) three different positions on the lens holder, changing the position and
tilt of the projection lens in relation to the optical engine (DMD). These metal plates are called shims. Because the distance between
the center of the DMD and the center of the projection lens is critical and may not be changed, it is important to add shims at one
end and remove shims (same thickness) at the other side at the same time:
• tilting down the lens = adding shims to 1 and to 2 and removing shims from 3
• tilting up the lens = removing shims from 1 and from 2 and adding shims to 3
• tilting the lens to the left = removing shims from 1 and adding shims to 2 and 3
• tilting the lens to the right = adding shims to 1 and removing shims from 2 and from 3
Image 3-69
Scheimpflug adjustment points
The best suited image to adjust the Scheimpflug is the specific focus pattern (green). It can be found in the internal patterns.
If the projector is in front projection, the following guidelines apply:
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R59770591 ENGINE KIT 26/08/2010
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