Sony 20mm F2.8 A-mount lens (SAL20F28)
The Sony 20mm F2.8 A-mount lens is a super wide-angle lens with 94° angle of view. It has a high level of distortion correction, correcting aberrations from a 25cm focusing distance to infinity. The SAL20F28 has ten elements in 9 groups, coated to reduce internal reflections, and it features a circular aperture for defocusing effects.
AF uses a rear focusing system, so if you want to use it with the Sony A7, you’ll need the LA-EA4 and not the LA-EA3 for it to work. The build is light and plastic, but doesn’t feel cheap at all.
Sony 20mm F2.8 Studio Test results
Vignetting with the Sony 20mm F2.8 A-mount lens is quite obvious at f/2.8 but is easily corrected in Lightroom. At f/5.6 and onwards, the vignetting is gone. Flare can be a minor issue when light sources are at an angle. The petal shaped hood does help here.
As it is based on the old Minolta 20mm, the colours and contrast are excellent and great for exposing rich skies.
If you’re planning on using the Sony 20mm F2.8 A-mount lens for landscape photography, the overall sharpness of this is excellent starting from f5.6. The other use would be an alternative portrait lens at f/2.8, and it’s possible to get a decent bokeh here while the centre remains sharp.