Get a blower and dismount your lens. Perform a mirror lock up (can be done in menu settings) to lift the mirror and then face the body downwards, blow the wind upwards into the body. blow repeatedly for several times and then disable mirror lock-up.
try capturing and see the dust still there or not. if still there, repeat it...
Added on May 9, 2010, 4:55 pmQUOTE(fcuk90 @ May 9 2010, 04:52 PM)
dust on the uv filter will not affect on the quality of the picture?
I mean if you put on uv filter all the time, u dont really need to clean your lens cuz it's protected by UV filter, no fingerprint will be produced at the lens.
So he said he removed uv filter to prevent flare, so got fingerprint. then use lenspen to clean, dont use cloth...
dust on uv filter also can be seen in photo lah

It's not the dust that "affect image quality", just the dust can be seen.
This post has been edited by zellleonhart: May 9 2010, 04:55 PM