Nikon D300S viewfinder dust removal
Sounds like dust on the focus screen... If the shots come out okay - I'd leave it alone. If you have to clean off the focus screen you have to be careful as they scratch pretty easily...
I think this about sums up the procedure for removing/replacing the screen:
If you do remove it - beware the screen scratches very easily...
|Valley by the light of a blue moon by cjf2|
from Down in the Valley
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from Dock or Pier
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