26
Adjusting the lens flange
If the subject is not focused properly in the telephoto
and wide-angle modes during zoom operations, adjust
the flange back (distance from the lens mounting
surface to the image-forming surface).
Once this adjustment is done, it need not be redone
unless the lens is replaced.
Adjustment method
1Attach the lens to the camera.
At this stage, do not forget to connect the lens
cable.
2Set the lens aperture to manual and open the
aperture.
3Set the lighting in such a way that the appropriate
video output level is achieved at a distance of
about 3 meters away from the chart used for the
flange back adjustment.
If the video level is too high, use the filters and
shutter.
4Loosen the screw securing the F.f (flange focus)
ring.
<Note>
On some lenses, this may be marked as F.b
(flange back) ring.
5Set the zoom ring to the telephoto position either
manually or electrically.
6Shoot the chart used for the flange back
adjustment, and turn the distance ring to adjust the
focus.
7Set the zoom ring to the wide-angle position, and
turn the F.f ring to adjust the focus.
Take care not to move the distance ring during this
process.
9Tighten the screw securing the F.f ring.
8Repeat steps 5to 7until the focus is adjusted at
both the telephoto and wide-angle positions.
<Note>
For details on the adjustment method and lens
positions, refer also to the operating instructions that
accompany the lens.
Approx. 3
meters