It is recommended that lenses with a price below 2k do not need to consider UV mirrors. Just pay attention when using it. Tens of dollars of corn and Kengo ultraviolet rays are not effective, which also affects imaging, especially when the light is not good. High-end B+W UV lenses are too wasteful for these cheap lenses. As for the "bull's head" above 10 thousand yuan, it is recommended to use B+W UV mirror. The effect of single-layer coating or multi-layer coating is not so obvious, depending on whether your wallet is bulging or not.
Pentax SP coating is his patent, mainly for good light transmission, not for dust and oil pollution resistance. As long as you pay attention when using it, whether you are equipped with a UV lens depends on how expensive the lens is. Never use a UV mirror that costs tens of dollars. Can only block ash. It definitely affects the amount of light entering. Can't buy it.