Sony SAL50M28 Service Manual page 57

4-4-2. Flange Back (f'F) Adjustment
Equipment
• 1000 mm Collimator
• Flange Back Tester
• A-mount Attachment
• Flange Back Gauge (43.50mm)
Adjusting Method
1) Perform "4-4-1. Flange Back (f'F) Check", and check that the checking lens is out of specification.
2) Turn the focus ring of the checking lens and align the infinity index of the focus scale plate to the distance index of the focus scale
window as shown in the Fig. 4-4-6.
1.75 6
0.6 2
32 16 16 32
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 flange back (f'F).
Flange back (f'F) of the checking lens = (Flange back gauge) + (Number of short-pointer revolution) + (Reading of long-pointer)
5) Calculate focus error amount using the following formula.
Focus error amount = Flange back (f'F) reading - 44.60 mm
Focus error amount: Amount that should be adjusted by the back adjustment washer thickness.
f'F: Flange back value (Reading value)
SAL50M28 (MACRO 2.8/50) (50mm F2.8 Macro)
ft
m
Align the center
2
16 16
Fig. 4-4-6
4-14