Sony SAL35F14G Service Manual page 61

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 µm" in the manual focus mode.
The tolerance is "0 ± 10 µm". (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.
Note 1:
Shoot images with the AE master lens and the lens to be tested using the same camera.
Note 2:
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.
Note 3:
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.
Method 1
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.)
Method 2
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)
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
acceptable range. If the error amount is out of the range, perform "4-7-4. Check/Write
Reference value
Focal length/
35 mm
SAL35F14G (1.4/35G) (35mm F1.4G)
Fig. 4-6-3
Distance (mm)
0.7 m (20 times)
1.4 m (40 times) 0 ± 37
2.1 m (60 times) 0 ± 83
Table 4-6-3
DSLR-A700 Defocus checker
(For DSLR-A700)
In case Good (0 ± less than 10 µm), frame
of waveform area displays in green.
0 ± 9
4-22
SB".