Thus, protection is a big business for camera retailers and manufacturers, and part of the reason why UV filters sell so well. These are thin, circular pieces of glass that fit over the front of your lens, and according to numerous photographers and retailers, can protect from scratches, smudges or cracks.
With some lenses, when used at full aperture (or nearly so), light reflected from the sensor back through the lens may be reflected from the rear surface of the filter back into the camera producing a ghost image on the opposite side of the optical axis.With a UV filter on the lens.The Goya 52 mm alpha MC UV Filter is a general use, clear filter that helps to absorb ultraviolet light. No additional coloration or contrast is provided, allowing you to pair this filter with others. The UV filter is also useful as a general protective filter to leave on lenses at all times. Home Page - https://www.skillshare.com/classes/Difference-Between-UV-Filters-For-your-Dslr-Polarizing-Filter-Camera-Quality/788581998 
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