The sony VCL-ECF1 Fisheye Converter is a conversion lens for the sony 16mm
f/2.8 and 20mm f/2.8 E-mount lenses. The 16mm f/2.8 Alpha E-mount lens has a
35mm equivalent length of 24mm which becomes 15mm when used with the VCL-ECF2,
and the 20mm f/2.8 lens goes from a 35mm equivalent of 30mm to 20mm.