Sony SAL55200 Service Manual ▷ View online
4-11
SAL55200-2 (DT 4-5.6/55-200 SAM) (DT 55-200mm F4-5.6 SAM)
4-5.
FOCUS-SHIFT (FOCAL LENGTH) /FLANGE BACK (f'F) CHECK/ADJUSTMENT
In this section, the check/adjustment of focus-shift, which arises from the change of the focal length by zooming, is described.
Equipment
• 1000 mm Collimator
• Flange Back Tester
• A-mount Attachment
• Flange Back Gauge (43.50mm)
4-5-1. Focus-shift (Focal Length) /Flange Back (f'F) Check
1. Preparations
1)
Perform “LENS GENERAL ADJUSTMENT GUIDE 3. FLANGE BACK (f'F) CHECK/OPTICAL AXIS CHECK”
2. Focus-shift (Focal Length) Check
1)
Set the zoom to the TELE end.
2)
Set to “44.56mm” by rotating the knob of flange back tester.
3)
Focus by rotating the focus ring from the near end side.
4)
Rotate the zoom TELE
→ WIDE and WIDE → TELE and confirm that the value at each focal length satisfies the specification.
Note:
Do not rotate the focus ring
Specification
Focal Length f (mm)
Flange Back Value f'F (mm)
200
44.56 (
±
0.15) (44.41 to 44.71)
135
100
44.56 (
±
0.14) (44.42 to 44.70)
70
55
44.56 ( +0.14, -0.05) (44.51 to 44.70)
Table 4-5-1
5)
If the flange back value (f'F) of the checking lens does not satisfy the specification in Table 4-5-1, perform “4-5-2. Focus-shift (Focal
Length)/Flange Back (f'F) Adjustment”.
3. Flange Back (f'F) Check
1)
Set the zoom to the TELE end and the focus to the over infinity end and then check that the flange back satisfies the specification.
Specification: Over infinity end
Focal Length f (mm)
Flange Back Value f'F (mm)
200
46.12 (
±
0.2) (45.92 to 46.32)
Table 4-5-2
2)
If the flange back value (f'F) of the checking lens does not satisfy the specification in Table 4-5-2, perform “4-5-2. Focus-shift (Focal
Length)/Flange Back (f'F) adjustment”.
4-1-2. Adjustment Flow Chart
4-12
SAL55200-2 (DT 4-5.6/55-200 SAM) (DT 55-200mm F4-5.6 SAM)
4-5-2. Focus-shift (Focal Length) /Flange Back (f'F) Adjustment
1. Preparations
Perform “4-5-1. Focus-shift (Focal Length)/Flange back (f'F) Check” and confirm that the flange back value (f'F) of lens to be checked
does not meet the specification in Table 4-5-1.
2. Adjustment Procedure
1)
Set to “44.56mm” by rotating the knob of flange back tester.
2)
Set the zoom to the TELE end (200mm) and adjust the focus by rotating the focus ring from the near end side.
3)
Set the zoom to the WIDE end (55mm) and adjust the focus by rotating the knob of flange back tester.
4)
Adjust the focus by rotating the knob of flange back tester and read the flange back value (Read value: a)
5)
Using the value read in step 4), calculate the amount of increase (or decrease) of back adjustment washer by the formula below.
(Amount of increase (or decrease) of back adjustment washer: x)
x = a - 44.56
x: Amount of increase (or decrease) of back adjustment washer
a: WIDE end (55mm), flange back value under the above condition
• In case that the amount (x) of increase (or decrease) of back adjustment washer is negative (-): Decrease the thickness of back
adjustment washer.
• In case that the amount (x) of increase (or decrease) of back adjustment washer is positive (+): Increase the thickness of back
adjustment washer.
6)
According to the result in step 5), adjust the thickness of back adjustment washer.
Note:
Measure a thickness of back adjustment washer with a micro-meter.
Back Adjustment Washer
Part No.
Description
t (mm)
3-277-057-01
BACK ADJUSTMENT WASHER
0.50
3-277-057-11
BACK ADJUSTMENT WASHER
0.30
3-277-057-21
BACK ADJUSTMENT WASHER
0.10
3-277-057-31
BACK ADJUSTMENT WASHER
0.05
3-277-057-41
BACK ADJUSTMENT WASHER
0.04
3-277-057-51
BACK ADJUSTMENT WASHER
0.03
3-277-057-61
BACK ADJUSTMENT WASHER
0.20
Table 4-5-3
Fig.4-5-1
Back Adjustment Washer
Mount Assy
Rear Light Shield Barrel
4-13
SAL55200-2 (DT 4-5.6/55-200 SAM) (DT 55-200mm F4-5.6 SAM)
7)
Set the zoom to the TELE end and the focus to the over infinity end.
8)
Adjust the focus by rotating the knob of flange back tester and read the flange back value. (Read value: b)
9)
Using the value read in step 8), calculate the amount of increase (or decrease) of 1st lens adjustment washer by the formula below.
(Amount of increase (or decrease) of 1st lens back adjustment washer: y)
y = (b - 46.12)/3.47
y: Amount of increase (or decrease) of 1st lens adjustment washer
b: TELE end (200mm), flange back value at over infinity end
10) According to the result in step 9), adjust the thickness of 1st lens adjustment washers.
Note:
Measure a thickness of 1st lens adjustment washer with a micro-meter.
Install or remove the lens assy with the universal wrench (J-6082-609-A) and the chip A (J-6082-609-1).
• In case that the amount (y) of increase (or decrease) of 1st lens adjustment washer is negative (-): Decrease the thickness of 1st lens
adjustment washer.
• In case that the amount (y) of increase (or decrease) of 1st lens adjustment washer is positive (+): Increase the thickness of 1st lens
adjustment washer.
1st Lens Adjustment Washer
Part No.
Description
t (mm)
3-277-015-11
1ST LENS ADJUSTMENT WASHER
0.50
3-277-015-21
1ST LENS ADJUSTMENT WASHER
0.30
3-277-015-31
1ST LENS ADJUSTMENT WASHER
0.10
3-277-015-41
1ST LENS ADJUSTMENT WASHER
0.08
3-277-015-51
1ST LENS ADJUSTMENT WASHER
0.07
3-277-015-61
1ST LENS ADJUSTMENT WASHER
0.05
Table 4-5-4
Fig.4-5-2
11) Repeat the steps 1) to 10) until the specification is satisfied.
12) Perform “4-5-1. Focus-shift (Focal Length) /Flange Back (f'F) Check”.
1st Lens Adjustment Washer
First Lens Barrel Assy
4-1-2. Adjustment Flow Chart
4-14
SAL55200-2 (DT 4-5.6/55-200 SAM) (DT 55-200mm F4-5.6 SAM)
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 (Only the specific equipment is listed)
• Aberration measuring cap 55mm (SAL55200)
4-6-1. Focus-shift (Aperture (Amount of spherical aberration)) Check
1. Preparations
1)
Perform “LENS GENERAL ADJUSTMENT GUIDE 5. FOCUS-SHIFT CHECK (APERTURE (AMOUNT OF SPHERICAL
ABERRATION))”.
2. Confirmation/Adjustment Procedure
1)
Set the zoom to the TELE end (200mm) and the focus to infinity and over.
2)
Check the focus-shift (amount of spherieal aberration) and confirm that the focus-shift satisfies the specification below.
Specification (TELE end 200mm): -0.02 to +0.18
3)
According to the result in 2), perform “4-9-3.
SB Check/ Write
SB” in the lens adjustment program.
4-1-2. Adjustment Flow Chart
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