Back focus adjustment

Back focus adjustment

Be sure to make back-focus adjustments when changing the lens mounting method or using a different lens. If required, adjust it as follows:

Back focus adjusting ring

Tighten

Loosen

 

C

BF

LO

 

 

Back focus fixing screw (M2.6)

Lens focus ring

With a fixed-focus lens

If the focus can not be adjusted correctly by rotating the lens focus ring, adjust the back focus as follows.

1. Loosen the back focus locking screw by turning it counterclocckwise ( ) with a screwdriver.

2. Shoot a pattern closely.

3. Turn the lens focus ring to ￿.

4. Turn the back focus adjustment ring to focus at the best point.

5. Tighten the back focus locking screw by turning it clockwise ( ).

MEMO

LENS FOCUS ADJUSTMENT MODE

At the time of focus adjustment, press the button at the side of the unit for at least one second to open the lens iris and to fa- cilitate focusing. At this time, “LENS FOCUS ADJUSTMENT MODE” will be displayed on the monitor screen.

When the adjustment has been completed,

press one of the buttons to can- cel focus adjustment mode.

Focus setting can differ on the color and on the black and white screen. Make adjust- ments so that the focus will come to the op- timum on both screens.

MEMO

When the subject is bright, the use of an ND filter permits more accurate back-focus ad- justment. (The ND filter reduces the amount of incident light upon the lens equally over the entire range of wavelength.)

With a zoom lens

If the image is out of focus when zooming (telephoto wide-angle), adjust the camera as follows:

1. Loosen the back focus locking screw by turning it counterclocckwise ( ) with a screwdriver.

2. Shoot a comparatively dark scene with thin lines.

3. Set the lens to the maximum telephoto position, and adjust the lens focus.

4. Set the lens to the maximum wide-angle position, and turn the back focus ring to adjust the focus.

(Repeat steps 3. and 4. two or three times.)

5. Tighten the back focus locking screw by turning it clockwise ( ).

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JVC TK-C1481 manual  Back focus adjustment, With a fixed-focus lens, Lens Focus Adjustment Mode, With a zoom lens