Barco Athena, Installation Manual

Page: 102 / 184

R5906790 /04 Athena 102
11.1 Scheimpflug introduction
What is Scheimpflug?
The lens holder has to be adjusted 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 distance between the DMD plane and
the lens plane (Lp1 → Lp2). The closer the lens plane comes 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 screen 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 DMD plane. This can be achieved by turning the lens holder to
remove the tilt (or swing) between lens plane and DMD plane (Lp3
→ Lp4).
Image 11-1: Scheimpflug principle
Scheimpflug principle
The "plane of sharp focus" can be changed so that any plane can be brought into sharp focus.
When the DMD plane and lens plane are parallel, the plane of sharp focus will also be parallel to
these two planes. If, however, the lens plane is tilted with respect to the DMD plane, the plane of
sharp focus will also be tilted according to geometrical and optical properties. The DMD plane, the
principal lens plane and the sharp focus plane will intersect in a line below the projector for
downward lens tilt.
Scheimpflug adjustment points
The front plate of the Lens holder is equipped with four bronze (Scheimpflug) nuts and four set screws with
lock nut. These screws and nuts are used for Scheimpflug adjustment.
Scheimpflug