Samyang's MF ultra-wide — 24mm f/1.4 with aspherical elements for astrophotography on full-frame.
The Samyang 24mm f/1.4 ED AS UMC is a manual-focus fast wide prime for full-frame, providing 24mm at f/1.4 with ED glass and UMC coating. Popular for astrophotography where the fast aperture maximises star light gathering.
Optically good — sharp from f/2.8 with decent centre performance at f/1.4. ED glass controls chromatic aberration. UMC coating reduces flare. The f/1.4 at 24mm is useful for astrophotography and low-light wide-angle work.
Available for Canon EF, Nikon F, Sony FE, and other mounts. 77mm filter thread. Approximately 680g — heavy. No electronic contacts on most versions. Full-frame coverage. Manual focus. Also sold as Rokinon 24mm f/1.4.
Available used very cheaply. The Sigma 24mm f/1.4 DG HSM Art is dramatically sharper with AF. For budget astrophotography and manual wide-angle work. Focus peaking on mirrorless helps. Check for smooth focus ring.