This is a 12mm with the angle view of 121 degrees. Whether you need it or not, the combination of a M-mount rangefinder and this lens makes the smallest ultra-wide system. The size become a little bigger than the first version, but it's rangefinder coupled and still much smaller than SLR lenses. Yet, the price is unbelievably reasonable. My rating goes high just because of this unique existence, but it's practically a nice lens with a sharpness wide open. Although it's a little soft in the corners wide open, but it becomes sharper across the frame if you stop down. The dramatic falloff is something you want to apply. This is the most cost-effective 12mm and it will come in handy for a situation you cannot step back.