Canon EOS 50 E - Page 148

Part 3: Repair Information
Select F3 Basis Sensor Data Output on the AF menu screen to display the image
data.
Check whether the output waveform is linear. If not, dust may be on the AF sensor.
AFBASIS
IBASIS sensorl
Dust
CV(Ll) CH(L2)
Left (L3) Right (L4)
Stand by, Communication with Camera in progress.
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