First let me say Im an extreme novice to photography. I have a canon T3i with 18-55mm, 55-250mm, and the 50mm lens. I just bought the 18-200mm today thinking I wouldnt have to switch lenses between my 18-55 and 55-250 on our upcoming trip. Is this a good excuse or am I missing something else that is different? 2. Should I try and sell my 18-55 and 55-250 now? 3. Im not sure what all the filters are about and dont know what I should buy. UV and polarized. I dont know what they are used for and if I should buy them for all my lenses. thanks for any help.