I'm thinking about getting a filter for my Canon rebel. The one I'm in need of would be for shooting sunsets. I only own two lens, Sigma 70-300 and the 50 mm f 1.8. I know the 50mm is used more so in portrait photography, but could I use this for the sunsets with good results? If yes what filter would I need. If not what filter for my 70-300? I'm about to purchase a circular polarizer for my 70-300. I'm new to using filters, so this may be a dumb question, would I still use a lens hood?