Manual focus fisheye lens for APS-C cameras with a Canon mount.
The Samyang 8mm f/3.5 UMC Fisheye CS is a full-frame-fisheye (diagonal fisheye, 180-degree on APS-C) lens for Canon APS-C DSLRs. CS = Crop Sensor (APS-C image circle); UMC = Ultra Multi-Coated. On an APS-C sensor it produces a full-frame fisheye effect (180-degree image fills the frame corners to corners). This is the standard single-version of the Samyang fisheye (vs the CS II).
8mm focal length, f/3.5 maximum aperture, diagonal fisheye (180-degree corner to corner on APS-C), CS (APS-C image circle), UMC multi-coated, Canon EF-S compatible mount, manual focus only.
The Samyang 8mm f/3.5 produces a full diagonal fisheye effect on APS-C sensors — the 180-degree coverage reaches the frame corners without a circular black border. This differs from the 8mm f/2.8 circular fisheye. Used for creative photography, action sports, architectural interiors, and VR pre-production.
Confirm this is the CS (APS-C) diagonal fisheye, not the circular fisheye variant. Test the fisheye effect on an APS-C body. Inspect the large protruding front element for scratches. Test aperture blades. Confirm EF-S mount engagement.