Sony SAL70200G (serv.man2) Service Manual ▷ View online
5-31
SAL70200G (2.8/70-200 G) (70-200mm F2.8 G)
5-5.
FOCUS-SHIFT CHECK/ADJUSTMENT (APERTURE (AMOUNT OF SPHERICAL
ABERRATION))
ABERRATION))
This section describes the check/adjustment of focus-shift amount resulting change of focal-length by aperture setting.
Equipment
• 1000 mm Collimator
• Flange Back Tester
• A-mount Attachment
• Flange Back Gauge (43.50mm)
• Aberration measuring cap 77mm (SAL70200G)
1. Preparations
1)
Perform “1. Preparations” of “5-4-1. Optical Axis Check/Adjustment and Flange Back (f’F) Check”.
2)
Set the checking lens focus to the infinity.
3)
Set the focal length 200mm.
2. Checking Method
1)
Set the lens aperture to the open aperture position, and measure the flange back (f’F).
2)
Set the aberration measuring cap 77mm on the tip of lens as shown in the Fig.5-5-1, then measure the flange back (f’F).
Fig.5-5-1
3)
Calculate amount of focus-shift using the following formula, and check that the specification is satisfied.
Note:
The focus-shift amount of the checking lens is difference between the flange back (f’F) of open aperture and flange back
(f’F) reading (using aberration measuring cap 77mm).
Focus-shift = Flange back (f’F) reading (using aberration measuring cap 77mm) - flange back (f’F) of open aperture reading
Specification
Focus-shift (mm) = – 0.1 to +0.14
4)
According to the result of the focus-shift, and replace the DM PC board unit.
DM PC Board Unit Distinction Method
Focus-shift
Part No.
Distinction method
0 to +0.1
1-480-056-21
Marking of microcomputer: It is not.
-0.06 to -0.01
1-480-056-31
Marking of microcomputer: 1
-0.1 to -0.07
1-480-056-41
Marking of microcomputer: 2
Table 5-5-1
Aberration measuring cap 77mm (SAL70200G)
5-32
SAL70200G (2.8/70-200 G) (70-200mm F2.8 G)
5-6.
ZOOM BRUSH POSITION ADJUSTMENT
Equipment
• Personal Computer (PC)
• Finished Inspection JIG (AC100 V only)
• Lens Adjustment Program (Actuator Checker)
1. Preparations
1)
Remove parts indicated in Fig.5-6-1 from the lens unit.
Fig.5-6-1
2)
Connected to equipment with checking lens. (Refer to Fig. 5-1-25 of Section 5-1-3.)
3)
Start up of “ActuatorChecker.exe”.
4)
Click
[Set up]
, and perform the initial setting. (Refer to Section 5-1-4.)
Zoom Rubber Ring
Polyester Tape (Black) 10mm
Polyester Tape (Black) 10mm
Brush cover
5-33
SAL70200G (2.8/70-200 G) (70-200mm F2.8 G)
2. Adjusting Method
1)
Set the zoom to “TELE end”.
2)
Adjust the position of brush so that the curved part of brush comes to the cut portion marked with
O on the zoom encoder flexible.
Fig.5-6-2
3)
Click the
[Search Zoom Adj. Point].
Fig.5-6-3
Note:
Adjust the brush in the right or left direction. At this moment, work with caution for the brush not to drop with its own
weight by shock when touching to the zoom.
R part of brush (zoom)
Zoom Encorder Flexible
5-34
SAL70200G (2.8/70-200 G) (70-200mm F2.8 G)
4)
The message “If Zoom-Adjustment-Point is found, Buzzer sounds.” is displayed in the pop-up window.
Search the position where the sound beeps at the TELE end.
Fig.5-6-4
5)
Fix firmly the brush with the polyester tape (black) 10mm not to shift as shown in Fig. 5-6-1.
6)
Shift the zoom by 10mm and confirm that the sound beeps at the TELE end again.
3.
In case of error display in the Search Zoom Adjustment Point
1)
When the error display and the NG display appear in the pop-up window, press the ENTER key to return to the initial menu and
perform “2. Adjusting Method” again.
Fig.5-6-5
Fig.5-6-6
2)
If the NG display appears again, check the items below as the defect of communication between finished inspection fixture and lens
is suspected.
• Checking the deformation of brush
• Dirt on the pattern
• Dirt on the signal board
• Poor connection of connector
• Defect of BL contact
• Broken wire at the mirror box fixture side
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