I am going out to AZ next week and I just purchased a D50 and a Nikor 50mm 1.8D lens to take pics of my daughter. This is the only lens I have at the moment. So I went out and purchased a 2 pack of filters. UV, and a polarizer. The package says I can use the UV as a lens "protector" all the time. Is this true? I shoot a lot indoors. 2. Do I need to take the UV filter off if I shoot Outside in Phoenix and put on the Polarizer, or can I just stack the two? 3. Any negative effects of stacking? Would I get the black corners with just two filters?