Sony AF DT 55-200 mm f/ 4-5.6 SAM Lens Manual
4-26
SAL55200 (DT 4-5.6/55-200) (DT 55-200mm F4-5.6)
4-5.
FOCUS-SHIFT/FLANGE BACK (f’F) CHECK/ADJUSTMENT
4-5-1. Focus-shift/Flange Back (f’F) Check
Equipment
• 1000 mm Collimator
• Flange Back Tester
• A-mount Attachment
• Flange Back Gauge (43.50mm)
1. Preparations
Perform “1. Preparations” of “4-3-1. Optical Axis Check/Adjustment”.
2. Focus-shift/Flange Back (f'F) Check
1)
While looking through the eyepiece of microscope, focus by turning the knob of flange back tester.
2)
Read the flange back values (f'F) of each focal length and confirm that they meet the specification in Table 4-5-1.
Flange back (f’F) of the checking lens = (SR flange back gauge) + (Number of short-pointer revolution) + (Reading of long-pointer)
Specification
Focal-length f (mm)
200
135
100
85
70
55
Tolerance of f’F (mm)
Max.
+0.03
+0.15
+0.14
+0.14
+0.14
+0.14
Basis value: 44.56 mm
Min.
–0.03
–0.15
–0.14
–0.14
–0.14
–0.05
Table 4-5-1
3)
If the flange back values of lens checked do not meet the specification in Table 4-5-1, perform [4-5-2. Focus-shift/Flange Back (f'F)
Adjustment].