Originally posted by SpecialK Its the viewfinder, not dust or light streaks. The typical dust problem is not a "bazillion" specks in a "pattern".
No mention of spots on the image itself, which if the camera was so dusty on the finder, at least some specks would be on the sensor.
No, not necessarily.
The sensor is protected by the shutter, which is in front of the sensor and separates it from the mirror box.
Also in front of the sensor there is an AA filter that is cleaned by ultrasonic movement of the filter at startup, combined with a non static, anti dust coating.
If not the glas of the VF is dirty, it is dirt on the mirror or the focus screen.
See the diagram and look for (blow for) dirt at:
- The viewfinder
- Translucent screen
- Mirror
Good luck, Bert