Sony SAL135F28 Service Manual ▷ View online
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SAL135F28 (STF 2.8(T4.5)/135) (135mm F2.8 [T4.5] STF)
4-4.
FLANGE BACK (f’F) CHECK/ADJUSTMENT
4-4-1. Flange Back (f’F) Check
Equipment
• 1000 mm Collimator
• Flange Back Tester
• A-mount Attachment
• Flange Back Gauge (43.50mm)
1. Preparations
1)
Set the equipments as shown in the Fig.4-4-1.
Fig.4-4-1
2)
Looking through the eyepiece lens, turn the eyepiece ring of the flange back tester so that cross line or scale in the view is the sharpest.
3)
Attach the flange back gauge (43.50mm) securely to the A-mount attachment and hold them together.
4)
Turn the focusing knob of the flange back tester so that fine scratches on the flange back gauge (43.50mm) is the sharpest.
Note:
Turn the knob in the direction of the arrow of Fig.4-4-2 for correct reading.
Fig.4-4-2
5)
Turn the scale ring of the dial gauge until the long pointer indicates “0”.
Note:
This position is the flange back (f’F) = 43.5 mm.
Memorize the position of short-pointer.
flange back gauge (43.50mm)
A-mount attachment
Objective lens (10x)
Dial Gauge (Min. scale: 0.01 mm)
Scale ring
Eyepiece lens (7x)
Eyepiece ring
Focusing knob
Focus on fine lines on the surface.
Always turn the knob in the arrow
direction for correct reading.
direction for correct reading.
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SAL135F28 (STF 2.8(T4.5)/135) (135mm F2.8 [T4.5] STF)
2. Checking Method
1)
Attach the checking lens to the flange back tester, and set the 1000 mm collimator.
Fig.4-4-3
2)
Set the distance scale tube of the checking lens to infinity end position and also set the stepless aperture to “A” while looking through
the microscope, and align the optical axis to the center of the chart image accurately.
3)
Turn the focusing knob of the tester until the chart image is the sharpest (red and green color areas are equal on the chart *).
*: Position in which the color of collimator chart changes from green into red and come into focus.
Also check the optical axis aligns with the chart center. (Refer to Fig.4-4-4.)
Note:
Figure shows example. The cause depends on individual lens.
Fig.4-4-4
4)
Calculate the flange back (f’F) of the checking lens using the following formula, and check that the specification of the Table 4-4-1 is
satisfied.
Flange back (f’F) of the checking lens = (Flange back gauge) + (Number of short-pointer revolution) + (Reading of long-pointer)
Specification
Focal-length
f’F (mm)
f (mm)
(Infinity position)
135
44.56 to 44.66
Table 4-4-1
5)
When the flange back (f’F) of the checking lens is out of specification of the Table 4-4-1, perform “4-4-2. Flange Back (f’F)
Adjustment”.
1000 mm collimator
Checking lens
Optical Alignment
Best alignment
Best alignment
Incorrect aligned
e.g. As the focusing knob is turned, the chart may appear blurry as illustrated.
The cause depends on individual lens.
e.g. As the focusing knob is turned, the chart may appear blurry as illustrated.
The cause depends on individual lens.
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SAL135F28 (STF 2.8(T4.5)/135) (135mm F2.8 [T4.5] STF)
4-4-2. Flange Back (f’F) Adjustment
Equipment
• 1000 mm Collimator
• Flange Back Tester
• A-mount Attachment
• Flange Back Gauge (43.50mm)
• Adhesive bond (B-10)
Adjusting Method
1)
Perform “4-4-1. Flange Back (f’F) Check”, and check that the flange back (f’F) of the checking lens is out of specification of the
Table 4-4-1.
2)
Set the distance scale tube of the checking lens to infinity end position.
3)
Turn the focusing knob of the flange back tester until the chart image is the sharpest while looking through the microscope.
4)
Calculate the shift amount (x) using the following formula.
Shift amount (x) = Measured value (f’F) at infinity end position - 44.61 mm
x = Shift amount that should be adjusted by the back adjustment washer
5)
Select the thickness of the back washer according to the result of step 4). (Refer to Table-4-4-2.)
Note:
Be sure to measure the thickness of the back adjustment washer by micrometer or vernier caliper.
• When the shift-amount is a negative value: Decrease the back adjustment washer thickness by the amount of shift amount (x).
• When the shift-amount is a positive value: Increase the back adjustment washer thickness by the amount of shift amount (x).
Back washer
Part No.
Description
Thickness (mm)
2-688-527-01
Back adjustment washer A
0.05
2-688-528-01
Back adjustment washer B
0.07
2-688-529-01
Back adjustment washer C
0.1
2-688-530-01
Back adjustment washer D
0.2
2-688-531-01
Back adjustment washer E
0.5
Table 4-4-2
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SAL135F28 (STF 2.8(T4.5)/135) (135mm F2.8 [T4.5] STF)
6)
Assemble the back adjustment washer, and perform the “4-4-1. Flange Back (f’F) Check” again.
Fig.4-4-5
Back Adjustment Washer
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