Nikon has issued a service advisory for its D600 DSLR
after several complaints of visible dust gathering on the camera's sensor.
Nikon issued the following advice to customers: "As a first step, please follow the guidance from the User’s Manual (pages 301-305) related to the “Clean Image Sensor” function and manual cleaning using a blower. If these measures do not remove all dust particles and you are still experiencing problems, then please consult your nearest Nikon service centre. They will keep your camera, examine it thoroughly, and service it as needed."
Nikon admits that the dust spots can be difficult to remove by the time that they are very visible on images.
Nikon did not specify the cause of the problem, despite the belief by some users that the dust is actually oil from the shutter itself.
Visit the Nikon services and support page
for more information and to read the full service advisory.