I've seen a couple of posts here, and elsewhere, wondering if certain aspects of an image are due to a camera/lens malfunction, the influence of a filter, post-processing abnormalities, etc. As a handy reference for any photographer, I think that the site referenced, below, is worth a look. It describes a wide variety of interesting optical effects in our atmosphere. Not only could this be used to figure out what is in a photo, but some of these phenomena are worth seeking out in their own right!


(For you astrophotographers out there, I found that site by way ofhttp://www.spaceweather.com, another fun reference.)