I try to take pics of my kids around 1/250th a second or faster like mentioned above. My lens AF is SUPER fast and reliable and I typically don’t have issues shooting them at ISO 400/ f2.8 on cloudy days using my 50mm, sometimes if they are further away I even can successfully step down to 2.2. But like I said, my AF is extremely fast and pretty spot on most of the time. The kit lens AF is slower but with the widest aperture being f/3.5, the DOF isn’t super shallow. I’m actually shooting with a Nikon D3100 crop sensor and the noise handling on it is actually really good. I know it’s an entry level camera, and definitely not a pro body, but it’s what I can afford right now.