I was really shocked when this lens arrived I never seen such a small wide angle lens especially super-wide angle one! 31mm long lens with 21mm focal length and takes 49mm filter ? Unbelievable!  I expected very good image quality before I started the test and I wouldn’t disappointed !! Amazing color rendering, sharp at wide open as well. Professionally built, superb quality lens.This angle view suitable for architectural and interior photography, short focus distance and lens sharpness provide a pretty good macro capability also.I don’t think so, many better lens available on the market at this price level and perhaps if pay much more for a lens it will not help you can’t get better quality.I am really, really proud owner of this lens.