Glance at the summary firstThe summary from the end of the lesson, as a road map before you start reading.
The focus area decides in which part of the frame the camera searches for sharpness: in a wide area the camera makes the choice and often picks the object in front or with clear edges, a single point focuses exactly where you want, a zone leaves the camera a choice within a small group, and a tracking area follows the subject across the frame together with continuous focus. Moving the focus point onto the eye with a joystick, direction buttons or the touchscreen is more accurate than focusing from the middle and turning the frame with shallow focus. Because in crowded and dim scenes the camera may choose the brightest or nearest face, the photographer needs to decide, on every skin, whose eye sharpness falls on.
Learning goal
You will be able to choose in which part of the frame the camera searches for sharpness. You will explain that in a wide area the camera, on its own, usually focuses on the nearest or most contrasty object; you will tell apart options such as single point, zone, wide area and tracking area; you will learn to move the focus point quickly within the frame; you will know that with shallow focus, recomposing after focusing can cause a small shift; and in crowded or dim scenes, among people of different skin tones, you will decide for yourself whose eye sharpness falls on.
The question
In a garden, you are photographing a little girl looking at you through a gap in a wooden fence. You raise the camera and half-press the shutter button; sharpness is found instantly. When you look at the photo, the fence's boards are sharp, but the child's face is a soft blur behind the fence. The camera found sharpness, but it found it in the wrong place.
Where should the focus point go? The camera gives its own answer to this question: most often it picks an object in front, with sharp edges, or one that catches the eye. But that object isn't always the subject of the photo. In this lesson we will talk about the camera's focus areas, where each one searches for sharpness, and why and how you should decide where sharpness goes yourself.
Context
In Lesson 4.3 you directed sharpness to a point with the touchscreen; the place you tapped became the focus point. The same idea holds on cameras, but there are more options. The previous lesson showed that turning the frame with continuous focus loses sharpness. This lesson shows how that moving is done, and in what size and shape the focus point can work.
The area where the camera searches for sharpness is called the AF area. This area can be a single small point, a group of points, or almost the whole frame. The area's size is a trade-off: a small area focuses exactly where you want but requires you to keep the subject under that point; a large area catches the subject easily, but the camera decides what to focus on. By the end of this lesson you will be able to make this trade-off consciously for every scene.
Simple explanation
Where does the camera focus on its own?
In a wide area, that is in the mode where the camera can search for sharpness across the whole frame, the camera decides for itself which object to focus on. The logic of this decision changes from manufacturer to manufacturer, but many cameras tend to choose the nearest object or the most contrasty edges. If there is a branch, a fence, the rim of a glass or a shoulder at the front of the frame, the camera may focus on that instead of on the subject. Many modern cameras give priority to a face or an eye when they detect one in the scene; this is a big convenience, but it doesn't always work.
That is why wide-area AF works well when the scene is simple and the subject is obvious: a single person in front of a plain background, a bird flying in an open sky. If there is more than one candidate in the frame, the camera's choice may not match yours. As with the child behind the fence, the camera finds sharpness quickly and decisively, but on the wrong object. To notice that an automatic decision has been made, it is enough to look at which point lights up on the screen or in the viewfinder after the focus confirmation.
What focus areas are there?
The options go by different names depending on the manufacturer, but their logic is similar. In single-point AF there is a small focus point, and you place it; the camera focuses only on what is under that point. It is the most reliable option for still subjects and for portraits that need exact sharpness. Some cameras have an even smaller version of the single point; it is used for focusing through branches or a fence.
In zone AF there is a group of several points; you place the group, and the camera decides which point within the group to use. It is a good middle way when keeping a moving subject under a small point is hard. Wide area, on the other hand, uses the whole frame and leaves the choice entirely to the camera. The tracking AF area works together with continuous focus: you choose the subject once, and the camera shifts the focus point along with the subject as it moves across the frame. For a running athlete or a flying bird, this is much easier than following the subject by hand.
How do you move the focus point?
There are several ways to move the focus point within the frame. Many cameras have a small joystick or direction buttons under your thumb; they slide the point in four directions and usually bring it back to the middle with one press. On cameras with a touchscreen you can place the point directly by tapping the screen; on some cameras it is also possible, while looking through the viewfinder, to use the screen like a touchpad and move the point by sliding your finger. Whichever way you use, the aim is to bring the point quickly onto the subject in the frame, most often onto an eye.
With single-shot focus, one alternative is, as in Lesson 10.2, to focus with the middle point, lock it, and set up the frame afterward. This works well in most situations, but there is a subtlety: when you turn the camera, the plane of focus turns with it. When working with a wide aperture and a close distance, for example when shooting a close portrait with a very open aperture such as f/1.4 or f/2, this turn can shift the plane of focus a little in front of or behind the eye, and the eye can soften slightly. In such situations, setting up the frame first and moving the focus point directly onto the eye gives a more accurate result.
Whom does sharpness fall on in a crowd?
In a frame with several people, wide area or face detection usually picks one person; this is often the face closest to the camera, the biggest, or the one the light falls on best. In a dim place, the most contrasty face is often the brightest face, and the camera may take sharpness to it. Because a dark-skinned person's face offers less contrast in this setting, the camera may skip them even if that person is the real subject of the photo. This isn't a preference of the camera but a result of edge measurement; in the end, though, sharpness falls on the wrong person.
That is why in a crowd you must decide who will be sharp. If your subject is clear, focus directly on their eye with single-point focus. If everyone needs to be sharp in a group photo, widen the slice of sharpness with a narrow aperture as in Lesson 8.3, and put the focus point on the eye of a face in the middle of the group or in the front row. After the focus confirmation, look at which face was chosen; if the camera's choice isn't the same as yours, move the point yourself. This is the way to make sure that every face, regardless of skin tone, gets sharpness if it is the subject of the photo.
Visual evidence
In a village garden, you are photographing a little girl looking at you through a gap in an old wooden fence. In the frame you take with wide-area focus, the fence's gray, weathered boards are sharp; the child's face is a soft blur behind. You switch the AF area to single point, and move the point with the joystick onto the child's eye in the gap of the fence. This time the fence's boards are soft lines in the foreground, and the child's eyes, eyelashes and the dust on her forehead are sharp.
The same evening, you are photographing three friends sitting at a table in a dim kitchen. In the middle, a dark-skinned friend is telling a story, and the two on either side are laughing. With wide-area focus, the camera takes sharpness to the face of the light-skinned friend closest to the lamp; the storyteller's face is soft. You switch to single-point focus, move the point onto the middle friend's eye, and stop the aperture down a little. Now the storyteller's eyes and their lips curving as they talk are sharp, and the two on either side are inside the slice of sharpness too. The same scenes; it wasn't the camera but you who decided where sharpness would fall.
Common mistakes
Common mistakeTrusting the wide area to always choose the right subject.
The camera may focus on the nearest or most contrasty object, for example a fence in front. The fix: after the focus confirmation, look at which point lights up; if it is wrong, switch to single point.
Common mistakeFocusing from the middle with shallow focus and turning the frame through a wide angle.
The plane of focus shifts with the turn, and the eye can soften. The fix: set up the frame first, move the focus point directly onto the eye.
Common mistakeLeaving it to the camera whom sharpness falls on in a crowded frame.
The camera may choose the brightest or nearest face. The fix: whoever the subject of the photo is, place the focus point on their eye yourself.
Summary
The focus area decides in which part of the frame the camera searches for sharpness: in a wide area the camera makes the choice and often picks the object in front or with clear edges, a single point focuses exactly where you want, a zone leaves the camera a choice within a small group, and a tracking area follows the subject across the frame together with continuous focus. Moving the focus point onto the eye with a joystick, direction buttons or the touchscreen is more accurate than focusing from the middle and turning the frame with shallow focus. Because in crowded and dim scenes the camera may choose the brightest or nearest face, the photographer needs to decide, on every skin, whose eye sharpness falls on.
Mini assignment
In this assignment you will compare focus areas in the same scene.
- Photograph a subject with an obstacle in front of it, a fence, branches or a glass, using the wide area, and look at where the camera focused.
- Shoot the same scene with single-point focus, moving the point onto the subject's eye or most important place.
- With a wide aperture, take two frames of a face up close, first focusing from the middle and turning the frame, then setting up the frame and moving the point onto the eye, and compare the sharpness of the eyes.
- In a dim scene with several people of different skin tones, look at which face the wide area chooses, and then choose your subject yourself with a single point.
Check yourself
- Did you notice the moment the wide area chose an object in front?
- In the frame where you moved the point onto the eye, is the eye sharper than in the frame where you focused from the middle and turned?
- In the crowded scene, regardless of skin tone, did sharpness fall on the eye of the person you chose?
Glossary
| Term | Short definition |
|---|---|
| AF area | The area where the camera searches for sharpness in the frame; it can be a single point, a zone or a wide area. |
| Single-point AF | An area option that focuses under a single small point placed by the photographer. |
| Zone AF | An area option where the camera chooses within a group of points placed by the photographer. |
| Wide-area AF | An area option that uses the whole frame and where the camera decides what to focus on. |
| Tracking AF area | An area option that, together with continuous focus, follows the chosen subject across the frame. |
Mini quiz
1. With wide-area focus, what does the camera usually focus on?
- A) Always the exact middle of the frame
- B) Usually the nearest or most contrasty object
- C) Always the farthest object
- D) Always the sky
2. To photograph sharply the eye of a child looking through a gap in a fence, which area is most reliable?
- A) Single-point focus, with the point moved onto the child's eye
- B) Wide-area focus
- C) Automatic selection mode
- D) The focus area doesn't matter
3. At f/1.8, when you focus on a face up close from the middle and turn the frame, why can the eye soften?
- A) Because ISO changed
- B) Because the exposure lock broke
- C) Because the white balance shifted
- D) As the camera turns, the plane of focus turns too, and in a shallow slice of sharpness it shifts in front of or behind the eye
4. In a dim kitchen, if the face of the dark-skinned friend telling a story is soft and the face of the light-skinned friend near the lamp is sharp, what do you do?
- A) Stay in wide area and shoot again
- B) Switch to single-point focus and move the point onto the storyteller's eye
- C) Turn off the lamp
- D) Sharpen the photo afterward
Answers
- B — In a wide area the choice is the camera's, and many cameras prefer the nearest object or the one with the clearest edges.
- A — A single point tells the camera to focus only on what is under that point; the fence's boards are ignored.
- D — When the frame is turned, the distance of the plane of focus from the eye changes; in a thin slice of sharpness, this small shift softens the eye.
- B — The camera chose the most contrasty face, here the brightest; if the subject of the photo is the storyteller, you take sharpness to them yourself.
Summary card
- Wide area: the choice is the camera's; whatever is in front or has clear edges wins.
- Single point: exactly where you want; zone: a small group; tracking: follows the subject.
- Move the point onto the eye with the joystick, direction buttons or touchscreen.
- With shallow focus, don't focus from the middle and turn; set up the frame, move the point.
- In a crowd, you decide whom sharpness falls on; on every skin, let the subject's eye be sharp.
Bridge to the next lesson
Moving the focus point onto the eyes is the most important step of a portrait. But what if the camera could find the eyes on its own? Today many cameras can recognize a person's face, even their eye, and sometimes the shape of an animal or a vehicle, and take sharpness there. The next lesson describes how eye and face tracking works, and in which situations this automation is enough and in which it isn't.