Yongnuo YN 14mm f/2.8N Super Wide-Angle Fixed Focus Lens Autofocus for Nikon F-mount Digital SLR Cameras

SKU: GW21.0005

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I think so, the Sony E mount should be compatible with the FE (=Full frame E) mount of the A7R series. 
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The front lens of the lens is strongly curved and has a permanently integrated lens hood, threads for screwing are not available on the optics. The cap is placed over the lens hood and held in place by latches. I don't see any options for attaching a filter, and I'm not aware of any factory solutions or products from other manufacturers. 
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In digital photography, UV filters are installed in front of the sensor. A screwed-on UV filter is therefore of no benefit!