7.7. CLEANING AND STORING LENSES
It's easy to become obsessed with keeping a clean lens, doing everything you can to keep even the smallest speck of dust off of the glass. However, while it's of course advisable to keep lenses reasonably clean of dust and certainly devoid of oily smudges such as fingerprints, in reality a bit of dust isn't going to affect your image. Additionally, the wider angle the lens, the less likely you are to see any of the dust in the image because you're compressing a much larger surface area into the same imaging space on your image sensor.
NOTE
Spots and dust on your image sensor are a significantly bigger issue and are more involved to clean (see Chapter 10 for more on image sensor care).
You can remove most dust with a bulb blower and a specialized camera lens brush, or a dust-free microfiber cloth. Even an eyeglass cleaning cloth, such as that available from an optician, works very well. Lenses are coated with a delicate, protective optical film that you do not want to harm in any way, and fingerprints are one of the worst things for them.
The first thing to ascertain is whether you actually have something on your lens that you need to clean. Many photographers have mistaken dust or smudges on their viewfinders or mirrors for something on the lens; of course, anything on the viewfinder or mirror isn't going to appear in your image!
If you do get a smudge on the surface of the lens, follow these steps:
Blow and brush the lens to get rid of any larger ...