Alongside the new FE 28mm f/2, Sony released two conversion lenses that attach to the 28mm and turn the combination into a 21mm ultra-wide lens and a 16mm fisheye lens.  Today, I’m reviewing the 21mm ultra-wide conversion lens, otherwise known as the SEL075UWC.  The 21mm conversion lens attaches to the front of the FE 28mm and creates a 21mm f/2.8 lens combination with full autofocus and autoaperture.  EXIF data is passed along as well, so the in-body image stabilization of the A7 II and new A7R II will automatically work at the correct focal length. The 21mm conversion lensretails for $249, so it’s an inexpensive way to gain an autofocus ultra-wide for your full-frame E-Mount camera. Sometimes these add-on lenses are more hype than real imaging solution, so I was very interested to see which of these things is true of the 21mm lens.  One thing before we start: If you haven’t seen my review of the FE 28mm f/2, make sure you check that out as well.