This picture is of my step-daughter. I told her to play while I took pictures of her and I ended up with this shot after she came down the slide. I am pretty proud of this picture but would have been happier if the top of her head was not cut off.
Focusing on fast moving kids is quite a challenge. Many cameras have a focus mode that is dedicated to moving objects. The camera will continue to autofocus (while you hold the button halfway down) right up until the instant you push the shutter release. In this case it would be focusing on her as she moves toward you. Alternatively, you could try manual focusing but it’s quite tough with such fast moving kids. You’ll note here that the backgrounf is in sharp focus but the girl is slightly out of focus.
2: Blown Out Whites
This area on the girls face is blown out or overexposed. On bright sunny days you may have to use a neutral density filter or stop down your camera to capture properly exposed images.
“Portrait” photos are “vertical” photos and “landscape” photos are “horizontal” photos. So when you shoot a portrait often shooting in portrait, or vertical is often more pleasing to the eye. Try that next time you are shooting this young girl 🙂
Also, cropping the top of someones head is often a good thing because it means you’re getting really really close to your subject. In this case I don’t feel that it detracts from the image too much.
The main thing is that you captured the moment! The decisive moment in fact.
Beyond that you put yourself in a position to capture that moment!
Your technique will improve if you keep practicing.