[kpon]

天空多了很多黑點 http://1drv.ms/1iTqute

[lucassean]

dust on cmos

[Ref54]

dust on cmos, protective lens or lens

[Clarence Tsang]

Try different apertures to see the difference. If no difference, the dust is on sensor, if there is less and more on different apertures, then it's on the lens (protective lens or the lens itself). Clean the protective lens, front and rear lens. If the condition remains the same, the lens has to be cleaned by technicians.