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

<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)

1Mount the lens on the camera. Do not forget to connect the lens cable at this time.

2Set the lens iris to manual, and open the iris.

3Set 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.

4Loosen 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.

5Set the zoom ring to the telephoto position either by manual or electrical means.

6Shoot the flange back adjustment chart, 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.

8Repeat steps 5 to 7 until the chart is focused properly at both the telephoto and wide-angle positions.

9Tighten up the screw that secures the F.f ring.