Back Focus Adjustment - JVC VN-V25U Instructions Manual

Connection / Installation
Inner Tripod Base Mounting Screws
Make use of 1/4-20UNC screws. The length of
the mounting screw shall be between 6 mm to
7 mm from the mounting surface.
Caution:
● Using a screw with a length longer than
specified may damage the internal parts of
the camera, while using a length shorter than
specified may cause the camera to fall off.
Use a washer to adjust the length from the
mounting surface.
Mounting Plate
Washer

Back Focus Adjustment

The CS mount is adjusted to the widest point of
the applicable range by default. When using the
zoom lens or C mount lens, or when the lens
remains out of focus upon using the focus ring,
readjustment is required.
● Follow the method below when necessary to
adjust the back focus.
● In order to adjust the back focus accurately,
do so according to the steps below upon
opening the lens iris using the iris adjustment
and ND filter.
(ND filter is a filter that is used to evenly
reduce the amount of light entering the lens
at all wavelengths.)
● Connect a video monitor to the [MONITOR
OUT] terminal at the rear of the unit, followed
by adjusting as follows.
Back Focus Adjustment Ring
Loosen
Lens Focus Ring
20
Max. 7 mm
Min. 6 mm
Tighten
Back Focus Fastening
Screw (M2.6)
Fixed focus lens
Adjust when the lens cannot be brought into
focus using the focus ring.
1.
Loosen the back focus fastening screw by
using a Phillips screwdriver and turning it in
the anti-clockwise direction
2.
Shoot the object or a fine pattern that is
farther away than the object
3.
Set the focus ring of the lens to
4.
Turn the back focus adjustment ring to obtain
a sharp focus
5.
Tighten the back focus fastening screw by
turning it in the clockwise direction, and
ensure that it is securely fastened
Zoom lens
Perform the zooming operation (Tele - Wide)
and adjust accordingly if it is out of focus.
1.
Loosen the back focus fastening screw by
using a screwdriver and turning it in the anti-
clockwise direction
2.
Shoot the object or a fine pattern that is
farther away than the object
3.
Set the zoom lens to Tele and turn the lens
focus ring to adjust the focus
4.
Set the zoom lens to Wide and turn the back
focus adjustment ring to adjust the focus
5.
Repeat Steps 3. and 4. for two to three times
6.
Tighten the back focus fastening screw by
turning it in the clockwise direction, and
ensure that it is securely fastened
∞