Focusing Nikon D5200?

So my dad got me the new Nikon D5200 this summer and I'm still trying to work out the kinks. What I don't understand no matter how much i study this thing is why it doesn't always focus when I'm recording something. Like it'll focus if I set it on that thing right away, but if I let's say.start off by recording a water bottle, but then switch over to a book next to it, it doesn't focus on the book. Why is that? Any tips and help would be nice.

The D5200 is an excellent still camera that happens to have a video feature.

Expecting to work like a real video camera is an unrealistic expectation.

Most videographers manually focus the lenses before shooting each scene in their script.

If you study the programs on television, you will notice that auto-focus is rarely used. Any follow focus is done by the "focus puller" whose job it is to keep the subject of the scene in focus.

Here is a video that shows you what is really necessary to make your fine D5200 (or other dSLR) into a viable video camera

https://vimeo.com/...m/15928756

As you can see, that requires a rather large investment.

What you may find much less frustrating is to buy a $150 camcorder made by JVC, Panasonic, Canon or Sony. One that shoots Full HD and has a nice 40x optical zoom if you want an auto-focusing video camera

To focus in video with any SLR setup, you either need to use manual focus (the MF switch on the lens then rotate the focus ring) or point the camera at the new target and half-press the shutter button to tell it to focus.

The thing about SLRs is that they do have video functions, but they really are geared towards photographs. Good choice on a camera though. You'll probably keep that forever.

You have, of course, read & studied the Owner's Manual for your camera haven't you? Still, I believe this video tutorial will help you: http://www.nikondigitutor.com/eng/d5200/index.html Who better than Nikon to teach you all about your Nikon D5200?

Read this review: http://www.imaging-resource.com/PRODS/nikon-d5200/nikon-d5200A.HTM They discuss shooting video about 1/2 way down if you'd like to skip everything above it. However, reading the entire review would be best.

Your camera has no autofocus in video mode. Why? Because it's not a camcorder.