Sigma lenses are amazing. I have a Sigma 30mm f1.4 and a Sigma 16mm f/1.4 lens and use them alternately on my Sony a5100 (surprisingly small, powerful camera set). The weight and build quality of Sigma lenses are impressive, but their optics are even more impressive. Autofocus focusing is a bit slower than Sony's OEM lenses, but they still focus fast enough for continuous video. used in low light conditions. I personally use this lens to hunt my son (who is still a toddler). A large maximum aperture allows me to use a faster shutter speed because it's fast and I don't want blur. Also, the wide angle allows me to get a great shot even if it moves to the edges of the frame before I can snap the shot. hello is fast Hahaha!