Milky way to work with my Canon full frame camera. I liked the large aperture (f/1.4) and the build quality seemed very good. However, I wasn't too happy with the coma distortion in the corners, which made the stars look like little flying saucers. In the end I decided it wasn't what I needed and sent it back. I took a Tamron 15-30 f/2.8. The Tamron isn't as fast, but the scaling capabilities have made it more versatile, and less distortion has made it more useful for Astroimo.