SAL70200G2 - Sony Digital Camera Service Manual (repair manual). Page 43

5-9

SAL70200G2 (2.8/70-200 G SSM Ⅱ) (70-200mm F2.8 G SSM II)

In this section, the procedure to adjust the focus change occurred when changing the focal length is described.

1. Preparation
Perform  1. Preparations  in the  5-3. OPTICAL AXIS CHECK/ADJUSTMENT .

2. Checking procedure
1)  Set the focal length to the TELE end (200 mm).
2)  Set the focus to the over infinity end.
3)  Confirm the flange back (f F) value at the TELE end.
4)  Shift the focal length from the TELE end to the WIDE end and from the WIDE end to the TELE end, and then confirm the flange back 

(f F) value of each focal length.

5)  Confirm that the focus-shift meets the specification with the flange back (f F) value obtained in step 3). If the focus-shift does not meet 

the specification, adjust it.

70 to less than 135

-0.1 to +0.1

135 to 200

-0.15 to +0.1

3. Adjustment procedure
1)  Set the focal length to the TELE end (200 mm).
2)  Set the focus to the over infinity end.
3)  Confirm the flange back (f F) value at the TELE end.
4)  Set the focal length to the WIDE end (70 mm) and confirm the flange back (f F) value.
5)  Calculate the results obtained in steps 3) and 4) using the formula below and determine the amount of focus point movement adjustment 

washer.

Amount of focus point movement adjustment washer = {(46.59 - TELE end f F) - (44.87 - WIDE end f F)}/ - 0.86

6)  Increment or decrement the washer according to the amount of Focus Point Movement Adjustment Washer.
 

When the amount of focus point movement adjustment washer is positive value (+):

 

 

Make the focus point movement adjustment washer thicker.

 

When the amount of focus point movement adjustment washer is negative value (-):

 

 

Make the focus point movement adjustment washer thinner.

2-691-553-01

Focus point movement adjustment washer A

0.05

2-691-554-01

Focus point movement adjustment washer B

0.07

2-691-555-01

Focus point movement adjustment washer C

0.1

2-691-556-01

Focus point movement adjustment washer D

0.2

2-691-557-01

Focus point movement adjustment washer E

0.5

7)  Set the lens unit as shown in the Fig. 5-5-2 and assemble the focus point movement adjustment washer.

 

Focus Point Movement Adjustment Washer

  Perform the flange back (f F) adjustment after competing the  5-5-2. Focus-Shift (Focal Length) Check/Adjustment .

1. Preparation
Perform  1. Preparations  in the  5-3. OPTICAL AXIS CHECK/ADJUSTMENT .

2. Adjustment procedure
1)  Set the focal length to the WIDE end (70 mm).
2)  Set the focus to the over infinity end.
3)  Confirm the flange back value (f F) at the WIDE end.
4)  Calculate the results obtained in step 3) using the formula below and seek the flange back correction value.

Flange back correction value (mm) = Flange back value (f F) at the WIDE end and over infinity end - 44.87 mm

5)  Increment or decrement the washer according to the flange back correction value.
 

When the flange back correction value is positive (+): Make the back adjustment washer thicker.

 

When the flange back correction value is negative (-): Make the back adjustment washer thinner.

2-691-806-01

Back adjustment washer A

0.05

2-691-807-01

Back adjustment washer B

0.07

2-691-808-01

Back adjustment washer C

0.10

2-691-809-01

Back adjustment washer D

0.20

2-691-810-01

Back adjustment washer E

0.50

6)  Assemble the back adjustment washer and perform the  5-5-1. Flange Back (f F) Check  again and confirm that it meets the specifica-

tion.

 

Lean the outer tube block and 
insert the back adjustment washer 
as shown in figure.

Back Adjustment Washer

Loosen the four screws

Outer Tube Block

Connect Barrel Unit