Adjustment Of Flange Focal Length - FujiFilm UA13x4.5BERD-S9 Operation Manual

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The flange focal length is the distance from the flange (mounting surface) of a lens to the focal plane.

If the focal plane of the lens does not coincide with the image plane of the camera, the object will be out of focus

during a zoom operation. To prevent this from happening, the adjustment of the flange focal length is required.

Make sure to carry out the adjustment when installing the lens to a camera for the first time or installing it to

another camera.

■ CONDITIONS OF OBJECT AND DIAPHRAGM

1. Object: Cut off the Siemens Star (the

chart made up of radial black and

white lines) at the end of this

manual and use it as an object.

2. Distance of Object: About 3 meters

3. Diaphragm:

Open or as near to open as

possible.

Note： The depth of field decreases by

opening the aperture of the lens, and

it becomes possible to focus on an

object more precisely. To precisely

adjust the flange focal length, carefully

adjust the focus as much as possible.

■ ADJUSTMENT

After installing the lens to the camera and

turning it ON, perform adjustment by

watching the monitor of the camera.

At this time, connect the lens cable to the

lens connector on the camera.

For the operation of focusing and zooming,

refer to "Focus Operation" and "Zoom

Operation" (pages 6 and 7).

a. Loosen the F.f locking knob by

rotating it counterclockwise.

b. Operate the zoom to set it to the wide

end.

c. Rotate the F.f adjusting ring using the F.f locking knob to focus on the Siemens Star located approximately

3 meters away.

The position where the radial black and white lines become sharpest is the optimum focus position.

d. Operate the zoom to set it to the telephoto end.

e. Operate the focus to bring the object into focus.

f. Operate the zoom to set it to the wide end again, and check that the optimum focus position adjusted in

step 'c' is kept.

g. To adjust precisely, repeat the above steps 'b' through 'f' several times.

(If the most optimum focus position usually holds in all zoom areas, the flange focal length is adjusted

precisely. If it is not focused, the flange focal length is not adjusted sufficiently. In this case, start

adjusting again from step 'b.')

h. Finally tighten the F.f locking knob firmly.