dust on when shoot with high aperture

[devil77]

Hi all,i just wana get some advice while i shoot with high aperture ard f/20 above,i could see small dot when reviewing the picture,but do not encounter this problem while shooting with low aperture..:
wat could be the problem??is it lens or sensor dirty??
your advice is appreciated....

 

[luna_sea83]

Sensor cleaning time

 

[chalib]

Hi all,i just wana get some advice while i shoot with high aperture ard f/20 above,i could see small dot when reviewing the picture,but do not encounter this problem while shooting with low aperture..:
wat could be the problem??is it lens or sensor dirty??
your advice is appreciated....

Dust on sensor....

 

[jtchoy]

Sensor dirty... Send for cleaning...