Samyang's manual-focus APS-C fisheye — 180-degree diagonal coverage at f/3.5 for creative and fun photography.
The Samyang 8mm f/3.5 UMC CS II is a manual-focus APS-C fisheye lens providing approximately 180° diagonal field of view. The CS (Crop Sensor) designation confirms APS-C-only image circle. No front filter thread — the bulbous fisheye element prevents conventional filter attachment. UMC (Ultra Multi Coating) reduces flare. At approximately 410g (Canon EF-S version) and manual focus only it is the standard budget APS-C fisheye option. Available in multiple mounts.
The optical design uses 10 elements in 7 groups including 1 aspherical element. Seven aperture blades. No front filter thread — the bulbous front element prevents standard filter use. At approximately 410g the lens is moderate. Minimum focus distance of 0.3m. No autofocus — fully manual focus. f/3.5 maximum aperture. CS designation confirms APS-C-only image circle.
The 180° diagonal fisheye on APS-C provides characteristic barrel-distortion spherical rendering. Manual focus at f/3.5 is practical for fisheye photography via hyperfocal zone focusing — at f/8 and beyond, depth of field extends from close distances to infinity, making manual focus adjustment minimal for landscape and architecture. The UMC coating reduces ghosting and flare against bright sky backgrounds that uncoated fisheye designs show.
On the used market the Samyang 8mm f/3.5 UMC CS II is affordable as an APS-C fisheye prime. Condition checks: front element for marks — the bulbous element has no filter protection — focus ring smoothness, and aperture ring operation. Confirm the mount version — available in Canon EF-S, Nikon F (APS-C), Sony E, Fujifilm X, and other mounts. Compatible with APS-C bodies in the specified mount.