Barco F70 - 4K6, User Manual

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601 – 426-03 F70 Series 56
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
Scheimpflug adjustment points are located on the lens mount. The F70 has three (3) set screws and three (3)
adjustment screws.
When to apply Scheimpflug?
Scheimpflug correction procedures may only be carried out by suitably trained and experienced
technicians.
A Scheimpflug correction should only be applied when the overall focus of the projected image is not equally
sharp (for example, if the projector is
NOT in parallel with the screen or as a result of a previously misaligned
Scheimpflug). Be aware that the consequence of applying Scheimpflug correction upon a screen not in
parallel with 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 recommended to place the projector
in parallel with the projection screen and use the SHIFT functionality of the Lens Holder to match the
projected image with the projection screen. If the SHIFT range is not sufficient then the projector can be tilted
and Scheimpflug can be applied.
4.9 Scheimpflug adjustment procedure
CAUTION: A Scheimpflug adjustment should only be carried out by properly qualified and
experienced projection specialists. A poor Scheimpflug adjustment may result in an extremely
degraded image and will require factory
— servicing to the projector.
Required tools
• Allen key, hex size 4
• Allen key, hex size 6
Preparation
1. Prepare the test area. Barco recommends a projector-screen distance of 2 metres be used for all Scheimpflug
adjustments.
Verify that the throw ratio of the installed lens matches the requirements of the installation area (projection
distance and screen size).
2. Check that the lens is correctly installed, and lens shift is in centre position.
3. If the installed lens has Iris control, open the Iris all the way up.
4. Open the focus ring all the way up.
5. Go to Main Menu / Test Patterns / Full Screen and select to display the Focus test pattern.
6. Zoom the lens to its widest opening (maximum image size on the screen).
Apply a Scheimpflug correction
1. Loosen the three set screws (reference 1b, 2b, 3b). Use a size 6 hex key to do this.
Physical Installation