I've always used UV filters as one of the best protection filters for lenses, as it's much cheaper to replace a scuffed, scratched, or dented filter than a premium bit of glass. Accidents happen, and I rely on a UV filter to give my optics a layer of protection. Unlike just using a clear filter, I also like that they block ultraviolet light waves and reduce haziness in images.
UV filters vary in price, depending on their optical quality and coatings. But most share a similar circular design which either screws onto the lens ring or attaches via a magnetic system. Kenko's Pro1D+ UV filter does the latter and is part of the company's Pro1D+ Instant action filter range (which includes a circular polarizer, variable neutral density filter plus polarizer combo, and even close-up filters). The magnet-attaching system means you can swap the filters almost instantly, which might be particularly important to landscape photographers working in changing light.
