– 31 –Adjusting the Lens FlangeWhen images are not clearly focused at both the telephoto and wide-angle positions during zoomoperations, adjust the flange back (the distance from the lens mounting surface to the imageformation surface).Once adjusted, the flange back does not need to be readjusted as long as the lens is not changed.Adjustment methodCheck the position of each part of the lens which must be operated in order to adjust the flangeback with the lens Handling Instructions.Adjusting the Flange Back1 Set the lens iris to manual.2 Open the iris. Position the flange back adjustment chart about 10ft (3 m) from the lens andilluminate it so that an appropriate image output level is obtained.Use the filter and/or shutter if the video level is too high.3 Loosen the Ff ring clamping screw.4 Set the zoom ring to the telephoto position manually or by electric drive.5 Shoot the flange back adjustment chart and turn the distance ring to bring the chart into focus.6 Set the zoom ring to the wide-angle position.7 Turn the Ff ring to bring the chart into focus.At this time, take care not to move the distance ring.8 Repeat this operation four to seven times until the lens is in focus at both the telephoto andwide-angle positions.9 Firmly tighten the Ff ring clamping screw.¡Refer to the Operating Instructions of the lens.Approx. 10ft (3 m)
