Lens Planarity (Scheimpflug Adjustment); Zoom, Focus And Iris - Barco CTHD-61B User Manual

4.9 Lens planarity (Scheimpflug adjustment)

4.10 Zoom, focus and iris

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This adjustment is rarely needed, do not apply it unless it is required.
Certain applications require fine adjustment of the lens planarity in order to obtain an image
that is focused. The projector is fitted with three adjustment screws (Allen key 3mm/5mm)
around the bayonet mount that facilitate such adjustment, a so called Scheimpflug adjust-
ment. Do not attempt adjusting without the required technical competence and refer to the
service manual found on our web for further info.
Figure 4-8. Scheimpflug Adjustment Screws
These lens functions are manual (not motorized).
• First adjust zoom to achieve the desired image size (if the lens has a zoom-function).
• Then adjust focus to achieve a sharp image. If the image is not sharp all over the sur-
face, please check the surface flatness and whether the lens axis is perpendicular to the
projection surface.
• Use the iris to adjust the contrast and focus depth of the image. Adjusting the iris will
affect the brightness; stopping the iris down increases contrast and image depth, but
reduces brightness.
• The zoom, focus and, iris rings can be locked in position for typical motion based instal-
lations to secure that the picture settings are not changed. Tighten the pre-installed M3
screws on each ring to lock the movement, using a 1.5mm Allen key, until the rings can
not be turned.
Figure 4-9. Positioning of Zoom, Focus and Iris rings (may vary on some lenses)
Zoom
Iris
Focus