5. Installation
5.9 Scheimpflug (Boresight) adjustment
What is Scheimpflug?
The lens holder has to be adjus ted so that the “sharp focus plane” of the projected image falls together with the plane of the screen
(Fp1→Fp2). This is achieved by changing the dis tance between the DMD plane and the lens plane (Lp1→Lp2). T he closer the lens
plane com es to the DMD plane the further the sharp focus plane will be. It can occur that you won’t be able to get a complete focused
image on the s creen due to a tilt (or swing) of the lens plane with respect to the DMD plane. This is also known as Scheimpflug’s
law. To solve this the lens plane must be placed parallel with the D MD plane. This can b e achieved by turning the lens holder to
remove the tilt (or swing) between lens plane and DMD plane (Lp3→Lp4).
SCREEN
DMD
Lp1
Lp2
Fp1
Fp2
SCREEN
DMD
Lp3
Lp4
Fp3
Fp4
(Scheimpf lug)
Image 5-10
Scheimpflug principle
Scheimpflug principle
The "plane of sharp focus" can be changed so that any plane ca n be brought into sharp focus. When the DMD plane
and lens plane are parallel, the plane of sharp focus will als o be parallel to these two planes. If, h owever, the lens
plane is tilted with respect to the DM D plane, the plane of sharp focus will also be tilted ac cording to geometrical and
optical properties. The DMD plane, the principal lens plane and the sharp focus plane will intersect in a line be low the
projector for downward lens tilt.
Scheimpflug adjustment points
There ar e three (3) Scheimpflug set and adjustment screws on the F50. The adjustment screw (a) is adjusted us ing an Allen Key
screw, hex size 3. The set screw (b) is locked and unlocked using an A llen Key screw, hex s ize 5. T he set screw is NOT used during
Scheimp flug adjustment.
a
b
1
2
a
3
Image 5-11
When to apply Scheimpflug?
Only apply a Scheimpflug correction in case the ove rall focus of the projected image is not equally sharp (can be caused if the
projector is NOT in parallel with the screen or a previous misaligned Sche impflug) . Take into account that the consequence of
applying Scheimpflug c
orrection upon a screen not in parallel w ith the projector is that the projected image differs from the rectangle
shaped image. In other words “distortion” of the projected image occurs. Masking will be required to solve the distortion.
The disadvantage of Masking is loss of content. Therefore it is strongly recomm ended to place the projector in parallel with the
projection screen and use the SHIFT functionality of the L ens Holder to m atch the projected image with the projection screen. In
case the S HIFT range is not sufficient then the projector can be tilted and Scheim pflug can be applied.
42
601–0307–00 F50 25/02/2016
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