A fuzzy or blurry viewfinder can affect the quality of photos.
The image that shows through a single lens reflex (SLR) camera's viewfinder is a direct representation of the resulting photograph. A subject or scene is reflected by a retractable mirror, which moves during shutter fire, into a smaller stationary mirror that is then shown in the viewfinder.
Diopter Adjustment
Some Nikon SLR cameras are equipped with a diopter adjustment lever or knob near the viewfinder window. According to a Nikon support page, this lever or knob adjusts the focus of the viewfinder image to better suit the vision of an individual photographer. If your camera has diopter adjustment, moving the lever up or down or moving the knob from side to side until the viewfinder image is in proper focus is recommended.
Dirty Mirror or Focus Screen
Since the retractable mirror relays the subject image into the viewfinder, collected dirt, dust or other smudging may cause a fuzzy image. The mirror should be cleaned gently by using a cottom swab dampened with glass cleaner and then wrapped in lens cleaning paper. A dirty focus screen, located directly above the mirror, can also affect the viewfinder image. This screen is covered with a highly sensitive coating and should be cleaned professionally.
Lens Issues
A lens that is dirty, mounted improperly or internally damaged will result in a fuzzy or blurred viewfinder image. Troubleshoot the lens by attaching it to another SLR camera and looking through the viewfinder. If the image is similarly blurred, the issue likely is a result of damage to the focusing mechanism or inner optics.
Tags: viewfinder image, lever knob, retractable mirror, should cleaned
