Sony 12-24mm f/4G Aperture Series @ 12mm: Melting Out Dana Lake #3 (A7R II)
See my Sony mirrorless wish list.
This series at 12mm, from f/4 through f/13 shows near to far field performance across the frame including how well close range sharpness delivers near the edges at close range. It shows a very common type of landscape scene with a near foreground and far background.
Sony 12-24mm f/4G Aperture Series: Raindrops Fall On Dana Lake
Includes images up to full resolution from f/4 through f/13.
The about $1698 Sony 12-24mm f/4G is a nicely versatile lens covering the ultrawide range. At this point I can recommend it from 12mm to 18mm, with some reservations, but given its light weight and versatility and 12mm wide end, a definite recommendation.
This lake was free and clear at this time in 2016. In 2017, a layer of snow up to 40 feet thick covers the far end. The record 50 feet of snowfall was probably double that in this low spot, blown in from wind.