I have been getting gray spots on my photos that I take with my Nikon D70. What is this from and how do I get rid of it? Thanks.
It sounds like you have dust on the sensor. Two options. Either send it in for service or learn how to clean it yourself. There are a few web pages out there with step by step illustrated instructions. Do a Google search.
Specks on the sensor filter certainly could be the problem, but you should make sure of it. The best way that I found for my D70 is to take a picture of say a lightbox or other uniformly lit area, overexpose by 2 or 3, use the smallest aperture to get a clear contour of the dirt specks and manually focus on infinite. If you have specks, they will very clearly show as dark areas. Be careful how you go about cleaning. I have used the method described on www.cleaningdigitalcameras.com with great success. Stay away from Hurricane blowers and SpeckGRABBERS! Good luck.