Easy-to-follow video tutorials help you learn software, creative, and business skills.Become a member
Your D800 has 51 autofocus points that it can choose from when it's trying to determine focus. How it chooses those focus points depends upon a combination of the focus mode that you're in and the autofocus area mode that you have selected. I'm currently in Single-Servo Autofocus. That's what this AF-S is right here. I am also in Single-Point Autofocus Area mode. That's what this little bracket here is. That's supposed to like a single focus point inside my frame.
What that means is that there is one focus point in my scene. By default it's in the dead center of my frame. And I can move it around if I need to, as you'll see in the next movie. But it's only going to focus right there. So when I half press, it focuses on that point. Now, right now that point is right between those two cameras, and so it's not going to be able to focus. I can also, in Single-Servo Autofocus mode, choose an Automatic Focus Point Selection. If I press my AF button over here on the side and turn my subcommand dial--the one on the front--I switch from S-- Single-Point mode--to Auto, and this lights up here showing that it's going to choose from amongst all 51 autofocus points.
So now when I half-press, the camera is going to try to determine what in the scene is the subject and it's going to focus on that point, and it's going to show me any focus points that sit on top of what it has decided is the subject. Now, bear in mind that focus is always a measure of subject-to-camera distance. So if there are several things in the scene at the same distance, it's going to show focus points on top of all of them. As long as one of those things is the subject that I want, then my subject will be in focus. So I'm going to do that right now.
I'm going to half-press the Shutter button, and it picks the camera on the left, which is exactly what I want. It's got focus points all over it, so I know that I'm in good shape, focus-wise. So I'm going to press the button the rest of the way, and it takes my shot. This is a great area mode to choose if I'm to needing to work quickly; if I'm in a rapidly changing environment and Autofocus needs to go as fast as it can, then this is a good way to go. The downside to this is that sometimes the camera may choose something as the subject that I don't think is the subject.
So in those cases, I might prefer to go back to my Single-Point Autofocus mode and manually choose my focus point, or employ a focus lock- and-reframe technique that we'll look at later. Now, if I switch to Continuous-Servo Autofocus, things change around a bit. Here I am in AF-C mode. I'm still in my Single-Point Area mode. So right now Autofocus is going to continue to work just as it always has. But let's change the AF Area mode to something that's going to work better with Continuous-Servo Focus.
So I'm going to press my AF button over here and I'm going to turn my subcommand dial. The first thing I get is D9. Then there is D21 and then D51. Those are dynamic-area autofocus modes. They are specifically designed for things that are moving. I'm still going to need to be sure that my Single Focus Point is sitting on top of my subject. The difference is, if that subject moves, the camera will try to keep it in focus. Your manual describes these different modes on page 93.
The 9-Point mode is good when you have a subject that's moving predictably. The 21-Point mode is good when you have subjects that are moving unpredictably. And the 51-Point mode is good for subjects that are moving very, very quickly and you're having trouble keeping them framed. There is an additional autofocus area mode that's good for tracking motion, and that is 3D, which also activates this autofocus point selection that we saw before. This is 3D Tracking mode.
It's going to try to track subjects that leave the selected focus point, but it's going to automatically select that focus point for you. It's great for subjects that are moving erratically, jumping around. If the subject leaves your viewfinder, you're going to need to let go of your half-press and start over. This is also a very good mode for things that are moving towards you and away from you. Most of the time you'll probably stay in Single-Servo Focus mode. It's the most everyday focus mode.
You may never actually go into Continuous Focus. There are ways that you can manually keep things that are moving around in focus. But if you do do a lot of sport shooting, a lot of nature shooting, anything where things are moving around a lot, you're going to want to dig into these Continuous-Servo modes and Area Focus modes. Again, check your manual for more detail. The main thing to know about these is you ought to practice with them little bit before you go into any really critical shooting situation.
Get unlimited access to all courses for just $25/month.Become a member
164 Video lessons · 45003 Viewers
64 Video lessons · 82991 Viewers
86 Video lessons · 53207 Viewers
148 Video lessons · 90198 Viewers