Philips VCM1976 - Manual (Page 11)

Caution:
The CCD sensor in the camera is sensitive to dust, if you remove the
iens from the camera you shouid always point the camera downwards
to minimize possible deposit of dust. Never touch the sensor and/or use
any cleaning materials. Only use clean, dry air to blow any particle form
the surface of the sensor.
When using a manual-iris lens, you should, in principle, set it at its
largest aperture. You may however reduce the lens aperture a few stop
when the camera is used in a high light intensity environment or when
an increased depth of field is required. This smaller lens aperture
affects the sensitivity of the camera (see before mentioned table).
Most lens mounts of auto-iris lenses are rotabtable so you can adjust
the lens in a desired position without loss of sharpness.
Back-focus adjustment; Adjustment of the back-focus distance of the
camera is necessary when the backfocus locking ring has been
released of when a particular lens gives an unshap image.
• Set the manual focus adjustment ring of the lens (if present)
(fig. A-6) to the FAR position or at infinity.
• Set the manual- iris (if present) to its largest opening.
• Aim the camera at an object at least 15 metres / 45 ft away.
• Loosen the back focus locking ring (fig. A-9) by turing it
counter-clockwise.
• Rotate the lens, including the CS-mount ring (fig. A-8), untill the
video-image on the monitor is sharp.
• Keeping the lens in place, tighten the back-focus locking ring by
turning it clockwise.
Note:
In case of an auto-iris lens:
• The back-focus adjustment is most accurate with the iris set to its
largest aperture, so it is recommended to do this adjustment
indoors under normal (reading) light circumstances without bright