I am using a Canon 70d with 18-55mm lens to capture fast moving action (volleyball) indoors. Lack of light was a problem, so I tried different settings but the pictures still are a bit dark. I am not sure I was doing things correctly or not. Another option I have is to buy a 18-200mm lens. Please help me to choose the correct settings - I know the 70d has lot of options to do this kind of job.