Hey everyone, novice photographer here... total "Dad With A Camera" )trying not to be - sigh) looking for some advice. So here's my scenario:I routinely shoot my children in their natural environment(playing, running around, etc.) and during the winter months most of these shots occur indoors. I haven't, yet, purchased a better flash so I'm often using the on-camera flash of my D5100 and even still end up needing to keep the aperture fairly open (f3-5 range) even with a higher ISO so that I'm able to get correct exposure while maintaining a sufficient shutter speed to freeze the motion. 99% of the time I am using the "AF-A" focus mode and Auto Area mode. Typically, I try to lock focus on the eyes and then re-compose(rear button focus, etc.) What I'm finding is that focus is no-longer sharp on the intended areas(face/eyes) after recompose. What I suspect is the culprit:Due to the relatively-thin DOF, after re-compose the face(eyes) are no longer within the DOF and fall just out of focus.(referenced from http://www.thephotoforum.com/forum/...hallenges/262742-focus-recompose-problem.html) What I think might solve the problem, but am not sure is the best/most-efficient method:- Change my focus area - "3D" seems like the best bet here in that it let's me select the initial focus point and then it tries to track the subject and changes AF points. - "Spot" seems like it would ensure perfect focus, but I fear will take too long to keep changing the focus point while trying to keep up with my toddlers.- Find some way to increase my DOF(Better flash? Other?). My exposure seems to be dictating the DOF in a way that I can't get around without purchasing additional gear or boosting the ISO to a point that introduces too much noise. Do you have advice for me?- How do you handle these types of situations? - Will any of my ideas actually work to solve my problem? - Do you have other/better ideas that will work for capturing extremely active subjects? - Am I going about this in the wrong way? I'd love to hear your input and advice... thanks for taking the time to read my novel of a post.