This is the second iteration of the fisheye adapter VCL-ECF1. In this case, it is dedicated to both 16mm and 20mm f2.8 Sony pancake lenses, on APS’C Sony mirrorless cameras. As for all adapters, it is rumored to be a low-quality solution to have a fisheye image, and it’s not cheap at all. But is it true? both those small lenses are not top performers, but all the images I see online made with the VCL-ECF2 seem to be quite, well… surprisingly good for an adapter.
Officially is stated that with SEL16F28 the fov is reduced to be like 10mm and with SEL20F28 to be like a 13mm
Bayonet mount. So, officially compatible with: SEL16F28 and SEL20F28 giving respectively 180° and 150° on the diagonal