Sony SAL35F14G Service Manual page 48

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
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 checking lens (b) - Average "G" value of master lens (a)
Specification
Aperture error = 0 ±12
2) When the aperture error is out of specification, perform "4-2-2. Aperture Diameter Adjustment".
SAL35F14G (1.4/35G) (35mm F1.4G)
Fig. 4-2-7
(a)
Check the "G" value
4-9