Focus-Shift (By Zooming) Check/Adjustment - Sony SAL24105 Service Manual

4-5.

FOCUS-SHIFT (BY ZOOMING) CHECK/ADJUSTMENT

In this section, the check and adjustment of change amount of focused point caused by the change of focal length are described.
Equipment
• 1000mmm Collimator
• Flange back Tester
• A-mount Attachment
• Flange back Gauge (43.50mm)
1. Check
Note:
Perform, referring to "4-4-1. Flange back Value (f'F) Check".
1) Check the flange back value (f'F) at each focal length (24, 35, 50, 70, 105).
2) The difference between maximum and minimum values of each flange back value (f'F) is the focus-shift.
Focus-shift = Maximum value of flange back value (f'F) - minimum value of flange back value (f'F)
Note:
If it does not meet the specification, adjust the focus-shift (by zooming).
Specification
f (mm)
24
35
50
70
105
Table 4-5-1
2. Adjustment
Perform, referring to the flange back (f'F) check/adjustment.
1) In case of completed lens, expose the body of lens by removing outer cover.
2) Set the focal length to 24 mm and the distance tube of lens to the infinite end. Then, measure the flange back value (f'F).
3) Leave the dial gauge as is, and set the focal length to 105 mm.
4) Loosen the screw fixing the focus stopper, and focus by rotating the manual control ring.
5) After adjusting, while holding the manual control ring not to rotate, set the focus stopper to the arrow direction and tighten the screw.
Apply the adhesive bond (B-10)
6) Repeat steps 2) to 5) until the value meets the specification.
7) After completing the adjustment, apply the adhesive bond (B-10) to the locations shown in the figure.
SAL24105 (3.5-4.5/24-105) (24-105mm F3.5-4.5)
f'F (mm)
44.55 to 44.77
44.55 to 44.80
44.55 to 44.90
Focus Stopper
Fixed Holding Tube Block
Fig.4-5-1
4-25