11
Adjusting the lens flange back
Adjust the flange back (distance from the surface where the
lens is mounted to the surface where the images are
formed) if the subject fails to be precisely focused at both
the telephoto and wide-angle settings when zoom
operations are to be performed.
Once adjusted, the flange back does not need to be
adjusted again unless the lens is replaced.
Adjustment method
1
Mount the lens on the camera. Do not forget to connect
the lens cable at this time.
2
Set the lens iris to manual, and open the iris.
3
Set the lighting in such a way that the appropriate video
output level is obtained at a distance of about 10 ft (3
meters) from the flange back adjustment chart.
If the video level is too high, use a filter or shutter.
4
Loosen the screw that secures the F.f (flange focus)
ring.
<Note>
Depending on the lens concerned, this ring may be
marked as the “F.b” (flange back) ring.
5
Set the zoom ring to the telephoto position either by
manual or electrical means.
6
Shoot the flange back adjustment chart, and turn the
distance ring to adjust the focus.
7
Set 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.
8
Repeat steps 5 to 7 until the chart is focused properly at
both the telephoto and wide-angle positions.
9
Tighten up the screw that secures the F.f ring.
<Note>
For details on the adjustment method and positions of the
lens parts, refer also to the instructions that accompany the
lens.
About 10 ft (3 m)
