Back Focus Adjustment - JVC GY-HD250U - 3-ccd Prohd Camcorder Instructions Manual

e_hd250.book Page 51 Tuesday, October 24, 2006 3:11 PM

Back Focus Adjustment

It is only necessary to perform this when the lens is attached
for the first time or when focusing is not correct in both the
telephoto and wide-angle positions.
• It is easier to adjust back focus when the subject is more
than 3 meters from the camera.
The optimal subject for this adjustment is a Siemens star
chart.
3 4, 6
Siemens star chart
5
1
2 7, 8, 10
1.
Set the IRIS mode switch to M (Manual).
2.
Set the zoom mode to M (Manual).
3.
Open the iris by turning the iris ring.
If the illumination is too strong, reduce it or move to a
darker place.
4.
Turn the zoom lever until the lens is at the maximum tele-
photo position.
5.
Bring the subject into focus.
6.
Set the lens to maximum wide-angle.
7.
Loosen the back focus ring retaining knob.
8.
View the same subject and adjust the back focus ring for
the best possible focus.
9.
Repeat steps 4. through 8. about three times for fine
adjustment until the subject remains in focus in both the
telephoto position and the wide-angle position.
10.
Tighten the back focus ring retaining knob to secure the
ring.
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