⟩ Explain me what Is a UV Filter?
A UV filter is a brilliant piece of kit, which is again often overlooked by beginners. What is does it simply protect the end of your lens from dirt, water and scratches. For a small investment you can help protect your expensive lens.
Like all glass, it's worth buying the best one you can, a cheaper unbranded one from eBay may, in fact, reduce the quality of the images which your camera can shoot. I would recommend a Hoya, Cokin or LEE filter as they are currently the best on the market.