Lateral chromatic aberrations may be a bit high when wide-open aperture is used, but the effect is mostly negligible from f/5.6 onwards. Like other Samyang lenses, the 7.5mm f/3.5 UMC Fisheye is purely mechanical, which doesn’t offer camera-controlled aperture and AF.
For some newer photographers, this may require some getting used to. But fortunately, focusing shouldn’t be a significant issue for a fisheye lens.