Amazon.com : 52mm Pro Series Multi-Coated High Resolution Digital Ultraviolet Filter for Pentax smc DA 50mm f/1.8 Lens, Pentax DA 18-55mm f/3.5-5.6 AL WR Zoom Lens : Electronics
49mm UV Filter for Canon EF 50mm f/1.8 STM Lens - Yahoo Shopping
Nikon NIKKOR Z 50mm f/2.8 MC Lens with UV Filter Kit B&H Photo