Raise your hand if you ever fog up your lens with your breath to clean it off… (I know I’m very guilty.)
Ok, so maybe it won’t kill your lens. According to Nikon though, there are acids in breath that can damage lens coatings. Instead, Nikon recommends via its support site to use a blower bulb, then brush, and wipe the lens with a lint free cloth.
How do I clean the camera lens?
The best way to clean a lens is to use a piece of lint free lens cleaning tissue and a small amount of Lens Cleaning solution. Do not use anything containing abrasives or solvents, only use Lens Cleaning Solution.
First we recommend taking a small blower brush to blow off or brush away loose dust or debris.
Next, place a drop or two of cleaner on the tissue (never directly onto the lens) and then wipe the lens in a circular motion, beginning in the center and working your way outward, removing any marks or smear.
If the above supplies are not available a clean, dry, soft, lint free cloth can be used to clean the lens. Do not breathe on the lens to fog it for cleaning. There are harmful acids in breath that can damage lens coatings. Just use the blower bulb, then brush, and wipe the lens in a circular spiral from the center outward.
The same method can be used to clean the viewfinder eyepiece of Nikon cameras
Now, if only we could get a straight answer on the D600 dust issue…