SAL50F14Z - Sony Digital Camera Service Manual (repair manual). Page 24

4-10

SAL50F14Z (Planar 1,4/50 ZA) (Planar T*50mm F1.4 ZA SSM)

2. Shooting procedure
1)  Click the [Start] of Defocus Checker 2 or DSLR-A700 Defocus checker to start the measurements.
2)  Adjust defocus value to obtain  0 

μ

m  in the manual focus mode.

 

The tolerance is  0 

±

 10 

μ

m . (Fig. 4-6-3)

3)  Click the [Stop] of Defocus Checker 2 or DSLR-A700 Defocus checker.
4)  Shoot an image by self-timer.
5)  Perform the steps 1) to 4) by using the AE master lens and the lens to be tested.

Shoot images with the AE master lens and the lens to be tested using the same camera.

Perform entire work within 10 minutes because values become unstable as the camera temperature increases.

 

 

If the work continues for 10 minutes or longer, cool down the camera and then restart the work.

Since focusing error amount increases in shooting images at a middle or long distance, comprehensive focusing error amount cannot be 
determined correctly only by results with short-distance setting. If the shooting distance using a 60 times chart cannot be ensured indoors, 
take either of the following methods.

 

 

 

 

Use 35 mm full size type camera (SLT-A99) and 40 times chart. (When using the 40 times chart, shooting distance can shorten to 2/3 of 60 
times chart.)

 

 

 

 

Check the focusing error amount of short distance using 20 times chart temporarily. After that, shoot the something images outdoors in the 
middle distance for using 60 times chart, and then check the focusing amount of middle distance.

 

Defocus Checker 2
(For SLT-A37/A57/A58/A65/A77/A99)

DSLR-A700 Defocus checker
(For DSLR-A700)

In case Good (0 

± less than 10 μm), frame 

of waveform area displays in green.

In case Good (0 

± less than 10 μm), frame 

of waveform area and defocus value display 
in green.

3.  The focusing error amount check
1)  Open the images shot with the lens to be tested and the AE master lens by the image display software on the PC. (Display the images at 

the same pixel magnification.)

2)  Check the displacement between the focus position (peak of image-formation) of the lens to be tested and the focus position of the AE 

master lens. (Refer to Fig. 4-6-4 and Fig. 4-6-5.)

3)  Compare the error amount in step 2) with the reference value of Table 4-6-3 and check whether the error amount is within the accept-

able range. If the error amount is outside of the range, perform  4-10-4. Focusing Error Amount Adjustment (Write 

⊿

SB) .

Focal length/

50 mm

Distance

(mm)

1.0 m (20 times)

0 

±

 9

2.0 m (40 times)

0 

±

 37

3.0 m (60 times)

0 

±

 83

<For reference 1: shooting image by AE master lens> (Fig. 4-6-4)
•  Assume it standard image in the setting environment.
•  If the peak of image-formation is to equal distance with AF assist chart position, it is ideal. In actual fact, the image of before and 

behind the peak is displayed. (Because the environment, the individual difference of camera and lens conditions are combined.)

•  The image of before and behind the peak, assume it reference standard image.
•  When shooting the image with sharpness setting of the camera to  +  side, it is easy to distinguish the peak of imaging area remarkably.

Enlargement of same pixel magnification

Example of image shot with 
a certain AE master lens under 
a certain environment.

Identifying the peak position of 
image-formation:
• Center of sharpest area
• Center of area with less color fogged
    - Front defocus area: Magenta fogged
    - Rear defocus area: Green fogged

Example where peak position accidentally matches 
the AF Assist Chart position