Basic Af Adjustment - Canon EOS 7 Service Manual

1.11 B AF A
ASIC DJUSTMENT
This adjustment must be carried out if the AF unit has been replaced. It must also be
carried out if the Main Flex Unit has been replaced, and the existing data cannot be
stored or transferred. It is not required if the existing data can be stored and
transferred. However, the AF sensor dust check and the AF focus data check must be
carried out.
P :
URPOSE
To adjust the data output from the BASIS sensor.
AGC: Adjust the AGC (Auto Gain Control) so that the BASIS sensor output
waveform is intact.
Dark: Store and correct the output waveform in the absence of light.
Shading: Store and correct bit-by-bit variations in the BASIS sensor output.
CAUTION
• AF basic adjustment must always be preceded by AF sensor positioning
adjustment and AF temperature compensation. The main mirror, sub-
mirror and light-receiving section of the AF sensor must be free of dirt and
dust when making this adjustment.
T :
OOLS
EF 50 mm f/1.8 tool lens
Video light
Tripod
Dark bag
Charts (For details of AGC charts, refer to "Locally Fabricated Tools" provided at the
end of this manual.)
P :
REPARATIONS
1) Mount the EF 50 mm f/1.8 production lens at about 1 m from the AGC adjustment
chart as shown in Fig. 4-10. Illuminate the surface of the AGC adjustment chart
with the video light so that the light amount is about EV9 (about TV=1/15, AV=F5.6
in the program mode).
2) Start the adjustment software, and select [F3] AF Adjustment menu in the MAIN
MENU.
Fig. 4-10 AGC Adjustment
4-19
Part 4: Electrical Adjustment
Make sure that the chart is
evenly illuminated with about
EV9 light.
Mount the lens
1.0m