Sony SAL100M28 Service Manual page 56

4) Click the calculate button to measure the image.
5) After measuring, check the "G" values.
Average "G" value of the three images shoot with master lens:
Average "G" value of the three images shoot with checking lens: (b)
Calculate button
Fig.4-2-7
3. Checking Method
1) Calculate aperture error using the following formula, and check that the aperture error is within the specification.
Aperture error = Average "G" value of master lens (a) - Average "G" value of checking lens (b)
Specification
Aperture error = 0 ±12
2) When the aperture error is out of specification, replace the midway move frame block and perform the check again.
SAL100M28 (MACRO 2.8/100) (100mm F2.8 Macro)
(a)
Check the "G" value
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