Samyang's fast ultra-wide for Sony — the 20mm f/1.8 manual prime for astrophotography.
The Samyang 20mm f/1.8 ED AS UMC is a fast ultra-wide manual-focus prime from Samyang for Sony E-mount APS-C mirrorless cameras, providing a 30mm full-frame equivalent field of view. ED (extra-low dispersion), AS (aspherical), and UMC (Ultra Multi-Coating) all indicate optical quality features.
The lens delivers 20mm (30mm equivalent on APS-C) at f/1.8 maximum aperture with ED and aspherical optical elements, UMC coating, Sony E-mount coupling without electronic contacts, and an APS-C image circle.
The 20mm f/1.8 at 30mm equivalent on Sony E APS-C is well-suited for street, interior, and low-light documentary photography where the combination of fast aperture and wide field of view is needed. The UMC coating improves flare resistance for night-time shooting near artificial lights.
Check focus ring smoothness. Inspect UMC coating on front element. Test aperture ring detents. No electronic contacts — no EXIF recorded. Verify APS-C image circle on Sony E-mount bodies.