Canon EOS-1DS MARK III Instruction Manual page 28

Manual Sensor Cleaning
Dust wMch could not be removed by the automatic sensor cleaning can
be removed manually with a blower, etc.
The surface of the image sensor is e×tremeJy delicate, if the
sensor needs to be cleaned directJy, having it done by a Canon
Service Center is recommended.
Before cleaning the sensor, detach the lens from the camera=
2
SeJect [Sensor cJeaning].
® Under the [t?_] tab, select [Sensor
cJeaning], then press <J_>.
SeJeet [CJean manually].
® Turn the <O> dial to select [CJean
manually], then press <J_>.
,3
SeJeet [OK].
® Turn the <O> dial to select [OK],
then press <_>.
_y,, I n a moment, the mirror will Iockup
and the shutter will open=
® "CLn" will blink on the top LCD panel.
4 End the cJeaning.
Set the power switch to <OFF>.
® If you use a battery, make sure it is fully recharged=
135