Yes, if yo can see it in the viewfinder, it is either on the mirror or on the focusing screen. The sensor dust dirt will be in pictures. The hair on mine was bad enough that it appears in every picture in the same spot at f/8 or higher, it got really irritating so I sent it out. Initially it cost me $40, which was ok. Then when I got it back, albeit they did a sensor cleaning they didn't listen to me that the problem was behind the low pass filter. So I sent it again, this time as soem suggested with pictures, etc. So I shot a picture of the sensor with the hair. I also included a picture taken at f/22. Then I got to speak with the tech. Everything seemed like to was finally going to get fixed, until this morning when it arrived. And my nightmare started!