Samyang 300mm f/6.3 ED UMC CS Mirror Lens - multiple Mount

A compact catadioptric (mirror) lens designed for APS-C and mirrorless cameras. Its mirror design allows for a 300mm focal length in a much smaller form factor than traditional refractive lenses. It features Extra-low Dispersion (ED) glass and Ultra Multi-Coating (UMC) to reduce flare and improve contrast, though like all mirror lenses, it features a fixed f/6.3 aperture and characteristic 'doughnut' bokeh. The manual focus throw on mirror lenses is often very short; check that the focus ring moves smoothly for precise adjustments. Inspect the internal mirrors for any signs of desilvering or fungal growth. SDS verifies the mount integrity and ensures the internal optical path is clear. Because it is a fixed aperture lens, ensure the mechanical connection to the camera body is clean.