Originally Posted by Tyto
1. Get a UV or skylight 1a or 1b filter for every lens you buy, and keep it on the lens always, unless you're using another filter.
2. If you're shooting water or other reflective surfaces regularly, invest in a good circular polarizing filter for each of your lens diameters--it reduces glare, gives better definition to clouds, sharpens colors, and allows you to "see through" glass and water to a limited extent. It's...