SAL18135 - Sony Digital Camera Service Manual (repair manual). Page 20

4-8

SAL18135 (3.5-5.6/18-135 SAM) (DT18-135mm F3.5-5.6 SAM)

1.  Adjusting Focus Shift (Focal Length)
 

* Disassemble the 1st group lens assy to the extent where it can be turned.

1)  Set the zoom to the WIDE end (18 mm) and the focus to the over infinity end.
2)  Adjust the focus by rotating the knob of flange back tester.
3)  Set the flange back tester below.
 

Read Value of 2) +  3.86 mm

4)  Set the zoom to the TELE end (135 mm) and the focus to the over infinity end.
5)  Turn the 1st group lens assy to focus the lens.
6)  Repeat steps 1) to 5) to match the flange back at the WIDE end (18 mm) and the TELE end (135 mm).

Tweezers

Hole

1st Lens Assy

1st Lens Assy

Hole

Apply the bond
(B-110)

7)  Bond the 1st group lens assy to secure it.

2. Flange Back (f F) Adjustment
1)  Set the zoom to the TELE end (135 mm) and the focus to the over infinity end.
2)  Adjust the focus by rotating the knob of flange back tester and read the flange back value.
3)  Calculate the increment or decrement of back washer by the formula below, using the result read in step 2).
 

BW = f w - 48.60

 

BW: Increment or decrement of back washer

4)  According to the value derived in step 3), increase or decrease the back washer.
 

In case that the value of BW is positive (+), increase the thickness of back washer.

 

In case that the value of BW is negative (-), decrease the thickness of back washer.

Rear Cover Barrel (8948)

Mount Assy

Back Washer

B/L Contact Box Assy

Part Number

t (mm)

4-294-776-01

0.05

4-294-776-11

0.07

4-294-776-21

0.1

4-294-776-31

0.2

4-294-776-41 0.5

5) Perform 4-5-1. Focus Shift (Focal Distance)/Flange Back (f F) Check .