The Minolta (later rebranded Sony) 20mm F/2.8 is another excellent and very affordable ultra wide angle lens that dates from the late 1980s; but don’t let the three decade old design fool you into thinking it’s just another cruddy old film lens. Minolta built this lens out of metal, and added auto focusing capabilities, which was rare in the mid 1980s. Optically, it’s very sharp, and uses a 10 element, 9 group optical design. No wonder it’s still available today brand new, or used for around $250. There are currently no auto focusing equivalent lenses in the Sony ‘E’ mount line-up; however, if you prefer a manual focusing modern equivalent, be prepared to pay $1500 for the Zeiss 21mm F/2.8—B&H Photo, Amazon, eBay, $800 for a Tokina Furin 20mm F/2—B&H Photo, Amazon, eBay), or $600 for a Rokinon 20mm F/1.8—B&H Photo, Amazon. If you have the Sony 28/2, you can get the converter for an ultra wide angle 21mm.
The Minolta/Sony versions of this lens would be an affordable way to get an ultra wide angle lens for your Sony ‘FE’ camera using an adapter. For the smaller Sony APS-C camera bodies, Sony makes a pretty good 20mm F/2.8 pancake type lens that I would recommend.
Mount your ‘a’ lenses to ‘e’ camera bodies.
Sony 20mm F/2.8 ‘a‘ mount lens. B&H Photo, Amazon, eBay.
Sony LA-EA3 ‘a’ mount to ‘e’ mount adapter $200 No review yet. B&H Photo, Amazon, eBay.
Sony LA-EA4 ‘a’ mount to ‘e’ mount adapter with auto focus $350 No review yet. B&H Photo, Amazon, eBay.
Check out the full size samples below, or go to the review and scroll to the bottom where I’ve added these samples, and made minor changes to the review; mostly page formatting etc. Note: these images were not intended to be viewed in their entirety, I was showing crops at the time, and this set was for the ‘center’ crops in the review.
Click the yellow buttons for full size versions from the full frame Sony A900.
The corners are a bit soft at F/2.8 and F/4, but sharpen up nicely at F/8. The centers are very sharp, even with the aperture wide open. Note: the foreground is not within the depth of field at wide apertures.