Sony VCL-ECF2 Fisheye Converter for SEL16F28 and SEL20F28

The VCL-ECF2 mounts on the front of Sony's SEL16F28 or SEL20F28 APS-C pancake lenses and turns either one into a fisheye. On the 16mm it produces a 10 mm focal length (15 mm equivalent) with a 180-degree angle of view; on the 20mm it gives 13 mm (20 mm equivalent) and 133 degrees. It is a quick way to add the exaggerated curved perspective without carrying a dedicated fisheye lens.

The converter has 4 elements in 4 groups, keeps the host lens's f/2.8 maximum and f/22 minimum apertures, and includes a fixed petal-shaped hood. It measures about 66 x 44 mm and weighs 150 g.