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Autofocus Options

Alright, let's continue our tour around the back of the camera. We have an AF-ON button which will activate the focusing system. And on its own, if you've just taken the camera out of the box and you're using the camera for the very first time right here, this button is not gonna do you much good because when you press down on the shutter release, your camera auto-focuses, and so anything you did with the thumb button back here to focus, your finger button up on the trigger of the camera is gonna re-do. This really comes into play when you get into the custom controls and you can configure this button to work differently or you can take off the autofocus on the shutter release so that you are working in back button focus. And so, we're gonna talk a lot about this, I have a new expanded section on button customization at the very end of this class. The next button is auto exposure lock. And so the way this is designed out of the box, let me give you a little demo right here, is that whe...

n we are in a program mode, shutter speed aperture priority for instance, and our camera is giving us a particular shutter speed and aperture as we move around, that number is gonna change according to the light and subjects that it sees. If we figured out, you know what, I wanna a lock it in here, you can press this button and you can see the asterisk comes up and it's gonna lock those numbers in, no matter where you move the camera. Now, it does reset after six seconds, and so I can shoot a picture here and it still stays at that 150 F3.5, no matter where I point it. Even if I put my hand in front of the camera. That can't focus there, but no matter how dark it is, it's gonna hold that until the six seconds is up and then it resets itself. Now, that's how it's designed to be used out of the box. I don't know a lot of people that actually use that feature in that manner. This is a button that can be highly customized, when we get to the custom controls in the camera. And this can be programed, and my favorite way to program this is as a second auto-focus button. So you can have two side by side buttons that both auto-focus but they do so in a different way. And you can really dig in and choose how these focus and we're gonna be doing that when we get into the custom settings and the button customization of this camera. The next button is for your AF points. And this is a big section so let's dive in and talk about autofocus points. So we have 61 autofocus points and we have many different options on how to choose the points and where we're going to focus. So the first that you need to do is you hit this button, and then there's actually a number of options. After that, to change, there will be the multifunction in the front, or the new AF area selection button on the back. They both do the same thing, they're gonna cycle through the different options. If you choose something like a single point, you will be able to move that point around using the little joystick, the multi-controller, on the back of the camera. If you prefer, you could use the back dial and the right dial to move those focusing points up, down, or left or right. You don't have to use all of these, you just choose whichever ones work for you. For most people, the key is pressing that corner, AF point selection button first, and the the AF area mode, which is either the multi-function or that AF area selection, the new button on the back of the camera, and then using the little joystick to move that navigation of where you want that focusing point. So let's talk about the different ways that you can focus. The first option is called spot autofocus. And you will see a double box. And what we're talking about is the inner of the two boxes. And so this is the smallest, most precise way that you can choose to focus. I don't use this very often at all. It is too small in many cases. And so this is something that you could potentially use if you have a very shallow depth of field lens. Like you have an 85 1.2 lens. And you really need to be careful, not just about focusing on the eyelashes and the eyeball, but exactly where on the eye you want focus. So if you were focusing maybe through a mesh fence, and it was a very small opening, you would choose this. But it is so small, it might be difficult to focus cuz there's just not enough to grab onto. What I and a lot of other photographers use is the 1 point autofocus which is the bigger of the two boxes. This is what most serious photographers use most of the time. It's precise but it's not so tiny it's hard to work with. And so it's a very valuable one because you can move it anywhere in the frame and it catches and it's just generally a very good system. The expanded area is also using one big box in the middle but if it can't figure out the situation, it looks to its nearest four neighbors for helpful information as to where to focus. And so it's always trying to focus with that center one, and you can move that one anywhere you want, and sometimes it does go down to three additional boxes or two additional boxes. But it's a good area if your subject is a little bit more erratic in its movement. Closely related is the same thing but with more help from more friends, alright. And so in this case, it's looking for the eight focusing points around it for additional help. But remember, both of these expanded areas, it is primarily starting with the center focusing point. And will only go to the other ones if the first one can't figure out the problem. The next one looks very similar, it's called zone, and it breaks the entire focusing area into nine areas. And you can go to any one of these nine areas and it's different than the previous one in that it's looking at all nine areas and it chooses whatever is closest to the camera. So it's not what's in the middle, it's whatever is closest to the camera. And I really like zone autofocus when I am shooting action photography. And so we're talking sports, wildlife, things that are moving around, for me this is my favorite one in most situations. Closely related but just a little bit larger in size is the large zone AF. And so these are more focusing points and it works in the same manner. It's not starting with any one particular point, it's looking at all of them and it's choosing whatever is closest in that large zone. And then finally, we have auto selection AF where it looks at all 61 points and it chooses whatever is first in there. Now if I was gonna hand the camera to somebody who knew nothing about how cameras worked, I would probably put it in the auto selection AF. That way it has a lot of help and it will just choose whatever is closest, which is usually what you wanted focused, not always, but usually. This is a system that I used. I was on the back of a boat and there was birds flying behind the boat in kind of the wake of the boat. And there was nothing between me and the birds. And they were very erratic in their movement. This worked perfectly for it because all I had to do was just get the bird a little bit into that focusing area and it could catch onto it. I normally don't use it in sports photography because referees and other players and other things get in the way of those focusing points and it might throw off my focusing. When you do have the camera in the servo focusing mode, this is where things are focusing continuously, you do get to choose the start point of the 61. So for instance, if you're photographing a race car coming around the left hand turn and you wanna have the car on the left hand side of the frame, you have all selection, auto selection AF turned on, you have AI servo turned on, you can then use the little joystick to move your starting point over to the left side of the frame. And it will start with that subject and then it will ignore things over on the right side of the frame but it will track that subject as it moves to different parts of the frame. And so it can be a valuable tool when you're shooting erratic moving subjects that you wanna position off center. So those are the different areas that you can use and it really depends on your subject, how much it's moving, what lenses you're using, your point of view, your composition. And so I can't just tell you, use these for this. It's a little hard to say but I can tell you for general photography, I use 1 point. When I am steadily holding the camera and I can easily focus it on something, portrait photography, landscape photography, product photography, architectural photography, I would choose 1 point AF. It's precise but it's not too tiny. For most action, I go with zone AF which is that box of nine and it looks for everything in the nine. If it's more erratic, I then use a larger area. But different people will find that for different sports, shooting in different ways, different systems work out. So that is our autofocus area. Now, let's talk little bit, let's geek out folks, do you guys wanna get a little technical? Let's talk about the focusing points on the camera. Now this camera uses what's known as a phase detection beam splitter. And this is the way SLR's work in their focusing system. And what they're doing is when the lens is out of focus, they're looking for lines that are broken because the information comes through. And it needs the line to hit both parts of that line sensor. In a horizontal line sensor which is looking for horizontal lines, the vertical line only hits one sensor at a time and it doesn't do any good. It can only figure out horizontal lines and an out of focus horizontal line will appear broken. And this great because now the camera knows, one, it's out of focus, two, how out of focus it is, and three, which way to turn the lens in order to get it in focus. And this is why SLR's are so good at focusing is that they can determine all this information virtually instantly. And that with a horizontal line. Now there are vertical line sensors so that it can pick up on vertical lines as well. And cameras will have a collection of one or both of these in it. Now this camera has a group of images that are group of sensors that look at horizontal line focusing. It has some that look at vertical line focusing. Now the ones that we all prefer are known as cross type, which means it has both of them built in at the same time so it's looking for vertical and horizontal lines which is awesome, we love those. And even better than that, there's a thing called dual cross type sensors, where it's looking at kind of the X as well as the plus. So it can pick up on any bit of contrast in information that it finds. So here is what we have in the 5D Mark Four. The focus points outlined in green here are looking only at horizontal lines. So they do not do well with vertical lines. They're looking for horizontal lines and they'll do it with lenses that have an aperture of F8 or faster which is all of the Canon lenses and most of them, even when you add a teleconverter onto it. The next group in blue here are cross type focusing. So these are really good focusing points. Now they're good with F4 horizontal and F8 vertical which means they're a little bit more sensitive with vertical lines cuz they'll sense them all the way down to F8. They're pretty good with horizontal but they're not really really good with that. The next group in purple here are cross type but they are very good at both horizontal and vertical. And so one of the themes that you'll see is things get better when you get closer to the middle. That's the general rule. The next group of them are these five in the middle and these are dual cross type. So these are the best. They work very good in horizontal, vertical lines. They're also quite good with diagonal. If you have a lens that goes down to 2.8, they're gonna be picking up on those diagonal lines. And on top of that, these are also known as high precision 2.8 sensors, which means, like I have on here right now, I have a 24 to 72.8 lens. Alright. And with that 2.8 aperture, it's letting in a little bit more light and the camera is able to use this high precision focusing which means it is even more precise about its focusing. And this is kind of an unpleasant topic here but when you're focusing, there are two things important. There is speed and accuracy. And if you have to pick one, well, okay definitely want it accurate, but if it doesn't get there quickly, it doesn't do me any good. And so there's kind of a balance that the Canon engineers have to design into the software of the camera. Do we want it to be fast, or do we want it to be accurate. And in this case, they put a little extra emphasis on being accurate because with a 2.8 lens, you often have shallower depth of field and you need more accuracy. And so if you're using an F4 or 5, 6 lens, you really don't need as much accuracy because the camera has more depth of field to work with. And so it's just kind of building an autofocus system that is highly tuned for the type of lenses that are on it. And finally, the center point sensitivity is good down to minus 3 EV, which in general terms, is about full moon light. It's under very very little light conditions. And I see this rated on many different cameras. This camera's at minus one, this one's minus two, minus three. There's a camera out there that is at minus four. In fact, this camera will do minus four EV if you were in the live view mode. But all of this is kind of hogwash and completely meaningless because the other factor that they don't take into account is what you are focusing on, how much contrast does it have? I mean is it, a black and white target that you're shooting at? Or is it a person's face where it's a little bit darker and a little bit lighter? And so all of this low light focusing really depends on the contrast of your subject. And so that's gonna matter the most and so if you are very good at figuring out, oh I'm gonna photograph on the eyelash cuz there's a little bit more contrast there. You'll be able to pick up under some very very low light situations with the camera. Something you may notice when you go into change focusing points, is there's gonna be a bunch of blinking focusing points on your camera. Those are the ones that are not cross type. They're only sensitive to horizontal lines so if you forget about it, every time you change focusing points, they're gonna blink at you to let you know. The ones that are steady are the cross type sensors. And in the menu system, one of the options we have, is you can limit the camera to only using cross type focusing points. If you say, I don't even wanna mess with these little quality points. But they can be helpful for tracking action in some situations and so it all depend on what you wanna do with your camera. Now the camera can focus down to F8 and this is something that's an improvement from the previous generations of 5D Mark Three's and many other cameras. This is also what the 1DX Mark Two has as well. Now Canon has zero lenses that have an F8 aperture. But they have a number of lenses that have an F4 or 5, 6 aperture that people are adding 1.4 and 2 times converters which results in a maximum aperture at F8. And so they're all capable of being used at F8. And I should probably and I don't have this on screen, I should probably have a really big asterisk. It's capable, but it doesn't always mean that they're gonna work real well. And so it really depends on the situation so what you should probably do is just hook up your lens and your teleconverter to the camera to see how well it works. There is a long list of pages in the instruction manual that has all of the Canon lenses grouped into groups A, B, C, D, E, F, G, H, I, J. And they're gonna have slightly different parameters about this one has 21 focusing points that work well. This one works with seven, this one works with one. And so there's a lot of different peculiarities when you hook up some of these different systems. In general, the center five, those vertical five in the middle, those are gonna work really well with virtually everything that you can possibly imagine. And in general, these are gonna work better with the new version three teleconverters than with the older teleconverters. They get some different results with that. And so even though they're all working, it's those 21 in the middle that are cross type sensors but you may not get all of those depending on the lens combination that you have. So that's your autofocus points, there's a lot in there and we will continue to talk about this because we do have an entire section on autofocusing and tweaking that when we get into the menu section. We've been talking about the multi-controller, we'll be using that for a number of things in the camera. One of the thing that's slightly aggravating to me is it's used for moving the focusing point around. But it's currently kind of locked off until you activate it with that focus point button on the upper right. So you can dive into the custom controls and you can release that lock, so you can just move that button any time you want to move your focusing points around the frame. And we'll be doing that in the custom control section. We have the new AF selection button, we were just talking about that. And move for changing our focusing points around.