5-4 Adjusting the Flange Focal Length
If the lens does not stay in focus properly as you zoom from telephoto to wide angle, adjust the flange focal length (the distance from the plane of the lens mounting flange to the imaging plane). Make this adjustment after mounting or changing the lens.
Adjusting the flange focal length
The position of the controls for adjusting the flange focal length vary somewhat from lens to lens. Check the identification of the various controls in the lens manual.
5
About 3 m (10 ft)
Adjusting the flange focal length
1
2 Open the iris. Place the flange focal length adjustment chart about 3 m (10 ft) away from the camera, lit well enough to provide a satisfactory video output level.
3 Loosen the fixing screws on the Ff ring (flange focal length adjustment ring).
4 Use manual or power zoom to set the lens to telephoto.