Adjusting the lens flange back

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

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 9.9 ft. (3 m)

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

3 Set the lighting in such a way that the appropriate video output level is obtained at a distance of about 9.9 ft.

(3 m) 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.