Sony DSLR-A300X / DSLR-A350X / SAL55200 Service Manual ▷ View online
4-29
SAL55200 (DT 4-5.6/55-200) (DT 55-200mm F4-5.6)
Fig.4-5-2
10) Set the 1000 mm Collimator to 44.56 mm.
11) Set the zoom to TELE end and turn the focus ring to focus.
12) Check the flange back value (f’F) at each focal length by zooming, confirm that the flange back (f’F) values meet the specification.
Specification
Focal-length f (mm)
200
135
100
85
70
55
f’F tolerance (mm)
Max.
+0.03
+0.15
+0.14
+0.14
+0.14
+0.14
Basis value: 44.56mm
Min.
–0.03
–0.15
–0.14
–0.14
–0.14
–0.05
Table 4-5-4
13) Repeat steps 1) to 11) until the value meets the specification.
First Lens Barrel Assy
1st Lens Adjustment Washer
4-30
SAL55200 (DT 4-5.6/55-200) (DT 55-200mm F4-5.6)
4-6.
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 55mm (SAL55200)
1. Preparations
1)
Perform “1. Preparations” of “4-3-1. Optical Axis Check/Adjustment”.
2)
Set the checking lens focus to the infinite.
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 55mm (F8 equivalent) on the tip of lens as shown in the Fig.4-6-1, then measure the flange back
(f’F).
Fig.4-6-1
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 55mm).
Focus-shift = Flange back (f’F) reading (using aberration measuring cap 55mm) - flange back (f’F) of open aperture reading
Specification
Focus-shift (mm) = 0 to +0.18mm
4)
When the focus-shift is out of specification, perform “3.Adjusting Method”.
Aberration measuring cap 55mm (SAL55200)
4-31
SAL55200 (DT 4-5.6/55-200) (DT 55-200mm F4-5.6)
3. Adjusting Method
1)
Adjust the G10-11 adjustment washer thickness according to the result of step 3) in “2. Checking Method”. (Refer to Table 4-6-1 and
Fig.4-6-2.)
When the focus-shift is a positive value: Increase G10-11 adjustment washer thickness by the amount of focus-shift.
When the focus-shift is a negative value: Decrease G10-11 adjustment washer thickness by the amount of focus-shift.
Note:
And “Curvature of field” is amendable by the variation of the G10-11 adjustment washer.
Part No.
Description
t (mm)
3-279-372-01
G10-11 ADJUSTMENT WASHER
0.05
3-279-372-11
G10-11 ADJUSTMENT WASHER
0.03
3-279-372-21
G10-11 ADJUSTMENT WASHER
0.02
3-279-372-31
G10-11 ADJUSTMENT WASHER
0.10
3-279-372-41
G10-11 ADJUSTMENT WASHER
0.15
Table 4-6-1
Fig.4-6-2
2)
Repeat the check and adjustment until the focus-shift tolerance meets the specification.
Note:
When perform this adjusument, perform “Projective Resolving Power (Curvature of filed) Adjustment” (Refer to page 4-25).
Rear Light
Shield Barrel
Shield Barrel
G11-13 Barrel Assy
G10-11 Adjustment Washer
A
A
4-32
SAL55200 (DT 4-5.6/55-200) (DT 55-200mm F4-5.6)
4-7.
ZOOM BRUSH POSITION CHECK/ADJUSTMENT
Equipment
• Adhesive bond (B-10)
1. Preparations
1)
Set the lens to be checked to the condition as shown in Fig. 4-7-1 by disassembling or assembling.
2)
Set the zoom to the TELE end.
Fig.4-7-1
2. Adjusting method
1)
Loosen the screw securing the brush.
2)
Adjust the zoom brush as shown in the figure and secure with the screw.
Note:
Adjust to match the conducting points on zoom brush to the cutting luck of pattern on Z.ECD board.
3)
Check the conduction between second pattern and third pattern from top with a digital multimeter as shown in figure.
• In case of the brush comes to the area circled where no pattern exists, no conduction occurs. (Adjusted)
• In case of the brush comes to the area circled where the pattern exists, the conduction occurs. (Not adjusted)
Fig.4-7-2
4)
Confirm the brush position by turning the zoom WIDE to TELE again.
5)
After adjustment, apply the adhesive bond (B-10).
Apply the adhesive bond (B-10)
Zoom Brush
Screw
Please match
A
and
B
Check the
conduction
conduction
A
B
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