Back Focus Adjustment; Iris Gain Adjustment - Canon CJ12ex4.3B Operation Manual

3 ADJUSTMENT
3 ADJUSTMENT

3-1. BACK FOCUS ADJUSTMENT

If the relationship between the image plane of the lens and the image plane of the television camera is
incorrect, the object goes out of focus when the lens is zoomed. Follow the procedure below to adjust the
back focus of the lens.
Extender Lever
Flange Back
Adjusting Ring

3-2. IRIS GAIN ADJUSTMENT

An iris gain adjusting trimmer is located on the front of the lens drive unit. The iris gain is set at middle
of range at the factory. However, if you wish to change the iris gain, adjust the trimmer using a small
screwdriver.
Iris Operation Mode
Change-over Switch
Clockwise
(to increase gain)
The adjustment and the setting can also be made on the information display. Refer to "Information Display
Manual" in the supplied CD-ROM.
Flange Back
Lock Screw
Loosening
Iris Gain Adjusting
Trimmer
Rubber Cap
1
Select an object at an appropriate distance ( CJ12ex/
CJ15ex/CJ14ex/HJ14ex : approx. 1 to 3m, CJ20ex/CJ25ex/
CJ18ex7.6B/CJ24ex/HJ17ex/HJ18ex7.6B/HJ21ex/HJ24ex/
KJ10ex/KJ17ex/KJ17ex II/KJ22ex/KJ22ex II : approx. 2 to 5m,
CJ18ex28B/HJ18ex28B : approx. 5 to 7m recommended).
Use any object with sharp contrast to facilitate the adjustment
work.
2
Set the extender lever to 1x. (Excluding KASE S type lens)
3
Set the iris fully open.
4
Set the lens to the telephoto angle by turning the zoom ring.
5
Bring the object into focus by turning the focus ring.
6
Set the lens to the widest angle by turning the zoom ring.
7
Loosen the flange back lock screw, and turn the flange back
adjusting ring to bring the object into focus.
8
Repeat steps 4 to 7 a few times until the object is brought into
focus both at the widest end and the telephoto end.
9
Tighten the flange back lock screw.
1
Set the iris operation mode change-over switch to the "A"
(Auto) position.
2
Pull up the rubber cap on the iris gain adjusting trimmer.
3
Turn the iris gain adjusting trimmer, using a small screwdriver.
As you look at the lens iris ring, set it to the position of
maximum gain at which no iris hunting occurs.
4
Close the rubber cap after adjustment completes.
E8