How to use manual focus on a digital camera lens. Autofocus scenarios and examples

Article text updated: 12/13/2018

Many modern SLR cameras are equipped with such advanced autofocus systems that it is often difficult to figure out how to use them. Whether we shoot with an entry-level camera or a professional camera, to get sharp pictures, we need to try to figure out how to use the different autofocus modes. Incorrect focusing, a blurry image can destroy the positive impression of the picture, and it is impossible to correct this shortcoming during post-processing in a graphics editor. Some photographers convert their photos to black and white to hide focus issues. If we learn how to focus correctly, we don't have to resort to these kinds of tricks, we get a much better result that our viewers will love. A clear image is what people want to see today when looking at our pictures. Someone may argue that sometimes a fuzzy picture looks “creative”, but here you need to understand: it’s one thing when we smear a photo for a specific purpose, and another when we spoil the picture because we don’t understand how our camera’s focusing system works. Once we understand how DSLR autofocus works, we can decide for ourselves when and to what extent the image will be out of focus.

Photo 1. Lessons for beginners. To get a high-quality photo, you need not only to choose the correct shutter speed, autofocus mode, but also be able to quickly rotate the zoom ... Nikon D610 camera. Nikkor 70-300 telephoto lens. Settings: ISO 1000, FR-98mm, f/5.0, V=1/2500 second

In today's free lesson photography, we will look at the main issues regarding autofocus modes in SLR cameras. Since the operation of automatic focus directly depends on what type of camera and its model we use, we, of course, will not describe in detail absolutely all AF modes, but will analyze a couple or two examples for clarity. Since I myself now have a full-frame Nikon D610 camera, and before there was a cropped Nikon D5100 camera, more emphasis will be placed on the work of this manufacturer's DSLRs. Well, I beg your pardon for absolutely beginner amateur photographers for the fact that the photo lesson will use specific vocabulary that is more understandable for advanced photographers.

1. How the autofocus system of SLR cameras works

One of the nice things about modern cameras compared to their film counterparts fifteen years ago is that we no longer have to manually adjust the focus. Digital photography is much more friendly to the amateur photographer in this aspect, because, unlike film photography, we immediately see the result and can easily change settings, retake a photo without thinking about the cost of film and photo paper. Over the past ten years, autofocus systems have become much better and even entry-level DSLRs boast a good autofocus complex. Well, how does such a system work in modern SLR cameras? Let's start with the very basics.

1.1 Active vs passive autofocus

There are two types of autofocus (AF) system: active and passive. Active AF “Active AF” functions by sending an infrared beam at our subject and picking up its reflection (“sounder” principle). The camera makes calculations and understands how far the object is from it, signals to the lens how much to adjust the focus. A nice advantage of the active focusing system is that it can work in very low light, at which normal (passive) autofocus will fail. The disadvantage of “Active AF” is that this mode can only be used in stationary conditions, for shooting motionless subjects, and works only at short distances: up to 5-6 meters. If we take pictures with a Nikon or Canon flash that has an “AF Assist” autofocus function, it will work in active autofocus mode.

The “Passive AF” autofocus system is based on a completely different principle: it does not send an IR beam and does not pick up its reflection in order to understand what is the distance between the camera and the focus object. Instead, special sensors inside the chamber are used to contrast definitions part of the light passing through the lens (called the “phase method”), or the camera matrix itself serves as such a sensor that determines the contrast of the image (called the “contrast method”).

What is meant by "defining contrast"? Without going into the wilds of terminology, this is the definition of sharpness in a certain area of ​​\u200b\u200bthe image. If it is not sharp, then the autofocus system adjusts the lens until sharpness / contrast is achieved.

This is why the passive autofocus system needs enough contrast in the frame to function properly. When the lens starts to “scrawl” over a uniform surface (such as a white wall or some kind of smooth tonal surfaces), this is because the camera needs objects with edges (contrast) that separate from the background in order to understand how adjust focus.

By the way, if there is an AF assist lamp on the front panel of our DSLR, this does not mean that the camera is in active focus mode: all that the lamp does is illuminate our object like a flashlight, i.e. The camera is operating in “passive AF”.

Many digital cameras, such as point-and-shoot cameras, camcorders, and the like, most often use a "contrast AF method" to achieve focus. At the same time, most modern DSLRs can be equipped with both systems for focus correction: phase and contrast autofocus.

Since the “contrast method” requires light to hit the sensor, the SLR camera must have the mirror up when focus is determined, which means that contrast autofocus in a DSLR can only be performed in “Live View” mode.

The phase method is great for focusing on moving objects, and the contrast method is great for stationary ones. Contrast-detect autofocus often performs better than phase-detection AF, especially in low light conditions. The advantage of contrast focusing is that it is enough to use any part of the image (including the one at the very edge) on the matrix to adjust the sharpness, while phase focusing requires the use of one or more focus points of the SLR. The disadvantage of the contrast method today is that it is relatively slow.

Many professionals believe that camera manufacturers will be able to solve this problem in the foreseeable future, as the speed of autofocus when shooting video is becoming more important for DSLRs, and some mirrorless cameras (in particular, the Micro Four Thirds, 4/3 standard) are already equipped with fast contrast AF. Modern high-end mirrorless cameras have two autofocus systems: a fast phase-detection autofocus for working in good light and a slow contrast autofocus for low-light conditions. Some manufacturers, in general, managed to embed the pixels of phase sensors directly into the camera matrix, which, in comparison with the traditional phase autofocus system of DSLRs, greatly increased the accuracy of the system.

If everything above sounds confusing, don't get too upset: the technical information presented above is intended to provide a general understanding of how autofocus works in a camera. Just remember that focus errors in the camera happen due to the lack of light passing through the lens and the type of focus mode we have chosen (as explained below).

1.2 Focus points

Focus points are small empty rectangles or circles that we can find in our camera's viewfinder. Manufacturers often differentiate between amateur and professional grade cameras by embedding various systems auto focus. Entry-level DSLRs usually have minimal amount focusing points, allowing you to focus, and advanced SLR cameras are equipped with a comprehensive, highly configurable AF system with large quantity focusing points. They are part of the "Phase AF Method" so that each point can be used by the camera's AF sensor to determine contrast.

Focus points are deliberately placed in a certain part of the frame, and their number differs not only in different manufacturers, but also for different models of cameras. Here is an example of two different types of autofocus with a different number of focus points and their arrangement.

As you can see, the Nikon D5100 DSLR has 11 points, while the Nikon D810 has 51 of them - big difference in the number of sensors. Does the number of focus points matter? Certainly - yes! This is not only because it is easier for us to compose a particular shot by focusing on a particular area of ​​the image, but also because the AF system can more effectively track the subject in the frame (extremely convenient when shooting sports competitions and wild animals). Although, it must be borne in mind that not only the number of focus points in our camera matters, but also their type.

1.3 Types of points in the DSLR AF system

Let's talk about the different types of autofocus points in DSLRs. As stated above, the number of points is not the only important parameter autofocus systems. The type of points is also critical to achieving accuracy. There are three types of focus points: vertical, horizontal and cross. Vertical and horizontal work in the same direction, i.e. these are linear sensors. Cross dots measure contrast in two directions, making them more accurate. Therefore, the more cross sensors in our DSLR, the more accurate the AF system works.

That's why, when a new model of a SLR camera is announced, in the review we can read something like: "The number of focus points is X, of which Y is a cross type." The manufacturer proudly emphasizes the number of points, especially the presence of cross points, if there are more of them in a new camera. Here, for example, in the list of the main differences between the Nikon D7200 and Nikon D7100 from the earlier model Nikon D7000, it was indicated that they have 51 focus points, including 15 cross points, and the old woman has 39 points, cross points - 9 pieces.

When we buy a new SLR camera that we plan to use for shooting sports or for hunting, we need to pay close attention to both of these parameters.

1.4 Other factors affecting the efficiency of the camera's autofocus system

As we can see, both the number of focus points and their type are important. Although, not only they affect the operation of auto focus. The quality and quantity of light is another parameter that greatly determines the performance of autofocus. Every photographer has probably noticed that the camera focuses perfectly when shooting on a bright sunny day on the street, and as soon as we enter a dimly lit room, the lens starts to “scour”. Why is this happening? Because, in low-light conditions on the subject, it is much more difficult for the camera to measure the differences in the contrast of the scene. Remember that passive autofocus is completely dependent on the light passing through the lens, and if the quality of the lighting is poor, then autofocus does not work satisfactorily.

Speaking about the quality of light, we should not forget about the features of the lens, that the maximum open aperture also has an effect on AF. If we shoot with old glass that has mold, dirt, too much dust, or there are problems with front and back focus, then auto focus, of course, will not work very accurately.

This is why professional lenses at f/2.8 allow you to focus much faster than amateur lenses at f/5.6. The f/2.8 aperture is the most suitable for fast focusing: the aperture is not too wide, not too narrow. By the way, usually lenses at aperture 1.4 focus more slowly than at f / 2.8, since more rotations are required. glass elements inside the structure to properly focus .

Focusing accuracy is important at these wide apertures because the depth of field is very small. Ideally, the aperture should be between f/2.0 and f/2.8 for the autofocus system to function at its best.

Smaller apertures, such as f/5.6, will cause less light to pass through the lens and make it harder for the autofocus system to work. For this reason, open apertures (with the exception of f/1.4) are preferable to clamped ones.

It should also be added that all modern digital cameras focus at an open aperture, so no matter what aperture value we choose (for example, f / 22), the aperture changes only at the moment of shooting .

Finally, the overall quality and safety margin of the autofocus system is of the highest importance. For example, the top professional Canon 1D Mark III DSLR, designed for shooting sports and hunting, after being released into the series, spoiled its reputation due to problems with autofocus. And it took forever for Kenon to release firmware to fix these shortcomings that annoyed professional photographers. Many of them switched to Nikon cameras precisely because of focusing problems. The camera was equipped with all autofocus modes, but it did not work correctly under certain conditions.

If we want to get the best system autofocus in modern DSLRs, especially for sports and wildlife photography, should be chosen from Nikon or Canon (although other manufacturers are quickly catching up with the market leaders).

2. Autofocus modes of digital DSLRs

Most DSLRs these days have the ability to shoot in a variety of out-of-focus modes depending on the situation.

It is one thing when we photograph a portrait of a calmly sitting person, and another when we shoot a running athlete or a flying hawk. When we shoot a stationary object, we focus once and take a photo. But in case the subject is in continuous motion, we need the camera to automatically adjust the focus at the moment when we take the picture. The good news is that our camera has a built-in function for effective work in such situation. Let's look at each of the focus modes in more detail.

2.1 One-Shot Focus Mode

Single-frame tracking focusing in Nikon cameras is designated “AF-S”, in Canon cameras this type is called “One-shot AF”. And it is an easy way to bring the lens into focus directly. We choose a focus point, and the camera measures the contrast simply by one point.

If we press the shutter button or the assigned AF button (if this assignment is possible in our model) halfway, the camera focuses, but if the subject moves, it does not refocus, even if we continue to keep the shutter button pressed halfway. That is, the focus remains "locked".

Normally, in single-servo AF mode, the camera must first focus in order for the shutter to be released. Therefore, if focus fails or the subject moves, pressing the shutter button will do nothing (due to a focus error). In some camera models it is possible to change the camera's reaction to the lack of focus (for example, with Nikon D810 we can set the “AF-S Priority Selection” setting in the “Shutter” custom settings menu, which will allow us to take a picture even if the camera is not in focus) .

There are some peculiarities of AF-S mode to keep in mind: if we have installed an external flash that has a red AF-assist beam, for it to work, we will need to put the camera in AF-S mode in order for it to work. The same is true for the autofocus assist lamp built into the front panel of the camera: it only works in AF-S mode.

2.2 AI Servo Focus Mode

Another focusing method available in modern DSLRs is called "Continuous Servo AF" or AF-C by Nikon and "AI Servo AF" by Canon. It is used to track moving subjects, and is absolutely essential when photographing. sports, wild animals and other non-stationary objects. The principle of operation of this mode is based on analyzing the movements of objects and predicting where it will be in the next instant, and setting the focus to this point.

The advantage of this mode is that the focus is automatically re-adjusted if the photographer or subject moves. All that is needed is to continue to hold the shutter button (or the assigned AF key, if possible) in the half-pressed state. The autofocus system will automatically track the subject. Compared to AF-S single-servo focus, AF-C continuous focus mode generally has a large number of settings (especially in the most expensive DSLRs) and can perform challenging tasks, such as tracking subjects with one or more focus points.

2.3 Hybrid One-Shot and Tracking Focus

Some cameras also have another mode called "Auto Servo AF" "AF-A" for Nikon or "AI Focus AF" for Canon cameras. It is a kind of hybrid, automatically switching between single-frame and continuous focusing. If the camera determines that the subject is still, it switches to AF-S, and if the subject is moving, it switches to AF-C.

In cheap DSLRs, AF-A mode is enabled by default and works decently enough in many situations. Many professional cameras do not have Auto Servo AF as it was designed for beginners.

2.4 Continuous focus tracking

Continuous focus focus mode, designated by Nikon with the letters “AF-F”, was introduced by the company for the new Nikon D3100 and D7000 models. It is intended mainly for shooting in Live View format. In this mode, the camera follows the subject and automatically adjusts the focus during video recording. Although the name sounds nice, in real life this mode does not work very well when shooting fast moving objects. Nikon Corporation engineers still have a lot of work to do to bring the “AF-F” mode to perfection. If you do not shoot video on a DSLR, then you should not turn on this mode.

Many professional photographers in photography lessons for beginners note that most of the time they have AF-C continuous focus tracking turned on, and only when the camera cannot focus in poor lighting conditions, they switch to AF-S.

2.5 Changing focus modes

If you do not know how to change the auto focus mode on your camera, it is better to read the instructions for it, as different models it happens in different ways. For example, for entry-level cameras Nikon D5300 or Nikon D5200, you need to press the "Info" button and select the focus mode with the joystick. And expensive DSLRs have a special button on the front panel, with which you can quickly switch between different modes. Here, for example, is how to change the AF mode on the Nikon D610 camera: press the AF mode button and simultaneously turn the control wheel.

The letter “C” appeared on the auxiliary screen, which means the camera is working in AF-C continuous focusing mode, switched to “S” - frame-by-frame focus turned on. Press "M" - switched to manual control of the camera focus.

3. AF area modes

To confuse novice photographers even more, many SLR cameras have items in their menus called something like “AF area mode”, which allow the amateur photographer to select several options for how focusing will work in AF-S, AF-C, AF- A and AF-F.

For entry-level DSLRs, such as Nikon D3100 or Nikon D5200, the settings can be changed through the menu, while for advanced cameras, such as Nikon D300s, Nikon D700, Nikon D3s or Nikon D3x, they are changed with a special selector on the rear panel (for SLR cameras, Nikon D810 and Nikon D4S cannot be reassigned to control this parameter to other buttons). Let's see what the AF area selection gives us.

3.1 Single point focusing area

When we select "Single Point AF" on a Nikon camera or "Manual AF Point" on a Canon camera, we only use one point to focus through the viewfinder to focus. That is, when we switch from one point to another with the joystick, the camera measures the contrast only in this particular section of the image, using vertical or cross sensors (depending on which one we have chosen). Many professional photographers advise using the single-point focus mode when shooting landscapes, architecture, and other stationary subjects.

3.2 Dynamic Focus Area Mode

In "Dynamic AF" mode for Nikon or "AF Point Expansion" for Canon cameras, we select one focus point, and the camera first adjusts focus on it. Further, once the focus is set, if the subject is moving, the camera will use the surrounding points to follow it and keep the focus on the subject. We expect it to follow the movement of the subject and keep it in focus while keeping the camera close to the initially selected focus point. If the camera selects surrounding/other points, it will not be visible in the viewfinder, but it will be noticeable in the finished photo.

Dynamic AF works great when shooting fast-moving subjects such as birds, because it's not easy for us to keep a bird in focus while it's flying. Advanced DSLRs, such as Nikon D7100, Nikon D7200 or Nikon D800, allow you to choose the number of dots surrounding the main one: 9, 21 or 51 pieces.

Thus, when we want to track a small area in the frame, we select 9 points, and if we need to track movement across the entire field of the frame, we assign 51 points.

Recently, many Nikon DSLR models also have a “3D tracking” mode - when we assign a point, and the camera then decides how many auxiliary ones it needs to track the change in the position of the object in the frame. The advantage of 3D Tracking mode is that the camera uses a built-in image recognition system to automatically read colors and follow the subject on its own, and you simply compose the shot as the subject moves.

For example, we take pictures white heron pacing between black birds. System 3 Dtracking will automatically focus on a white bird and follow it even if the bird moves or the camera moves, allowing us to compose the shot .

If we compare the modes "Dynamic AF" and "3D Tracking", then in the first case a certain number of points will be used, and in the second - all available to follow the subject. In this case, "Dynamic AF" uses certain "zones", activating only the surrounding focus points (as many as we have selected in the settings). For example, we have selected 9 points, tracking will work as long as the object is in the zone of 9 focus points surrounding the main one. If the subject leaves this area, the camera will not be able to focus. But in the 3D tracking mode, the camera will continue to observe the object (the newly selected points will be displayed in the viewfinder), even if it is significantly farther away from the originally selected point.

Professionals use the dynamic autofocus mode during bird and wildlife photography, using a small number of points: 9 or 21 pieces. There are different opinions about 3D tracking, as it is not as fast as with, for example, 9 dynamic AF points.

3.3 Auto focus area selection mode

At Nikon cameras it is referred to as "Automatic AF Area Selection", Canon has "Automatic AF Point Selection" and is a "point and shoot" focusing method. The camera automatically chooses what to focus on. It - a complex system, capable of recognizing the skin color of a person in the frame and automatically focusing on it. If there are several people in the frame, the focus will be selected on the one closest to the camera. If there are no people in the frame, then, usually, the camera focuses on a near or far object. If we have selected AF-S and Auto-area AF modes, the viewfinder will display the engaged focus point for a second, allowing us to confirm the area the camera has focused on.

The same is possible for Canon cameras, but they call it “Automatic AF point selection in One-Shot AF mode”. It's hard to say why this mode is needed, because professionals like to control all the shooting parameters, instead of letting the camera do it for them.

3.4 Group focus area mode

The latest Nikon SLR cameras, such as the Nikon D810 and Nikon D4S, have a new focus area selection mode “Group AF”. Unlike "Single-point AF", not one, but five focus points are used to track subjects. This mode is better for setting the starting point for focusing and tracking subjects than "Single-point AF" or "Dynamic AF", especially when it comes to shooting small birds that constantly flutter from branch to branch and can be difficult to catch in focus and follow them. In such cases, “Group AF” can greatly help the photographer and give away top scores than "Dynamic AF" because it is more accurate and gives shot-to-shot stability.

How does the group focus area mode work? We see 4 focus points in the viewfinder, the fifth, in the center, is hidden. We can move the group by pressing the joystick on the back of the camera (ideally we want to stay in the center because the focus point in the middle of the frame is a cross point, more accurate). When we have aimed at the subject, all five points are activated at the same time for initial focusing with priority on the nearest subject.

This is different from "Dynamic AF" with 9 points, which has priority on the selected center point. If it was not possible to focus on the central one (low contrast), the camera will try the remaining 8 pieces. Initially, the camera always focuses on the center point, and only then moves on to the other 8 pieces.

In turn, “Group AF” uses all 5 points at the same time and tries to focus on the nearest subject without giving the advantages of any of the 5 points.

Group AF mode “Group AF” is especially useful for shooting birds, wildlife, and non-team sports. In the example above with cyclists, if our goal is to focus on the front rider, better fit“Group AF”, because in this mode the camera will follow the athlete closest to it.

Another good example is a bird sitting slightly above the photographer so that the background behind it is almost invisible. In Dynamic AF mode, no matter where you aim, the camera will first try to focus. If we aim the lens directly at the bird, the camera will focus on it. If we accidentally aim at the background, the camera will focus on it.

Therefore, shooting small birds can be a little difficult, especially in bushes, or if the branches on which they sit are constantly staggering. The choice of the initial focus point is very important, and the sooner we choose it, the higher the chances of catching the bird in focus and following it, especially if it suddenly decides to fly away. As stated above, the “Group AF” mode does not benefit from any focus point, all 5 pieces are activated at the same time. In this case, since the bird is sitting closer than the background, once the group of 5 points is close to it, the camera will always focus on the bird and not the background. Once we have selected focus, the camera in Group AF will follow the subject, but again only if one of the 5 points is next to the subject. If the subject is moving fast and we don't have time to turn the camera in the same direction, the focus will be lost, just as it would be with 9-point Dynamic AF.

Some photographers say that the "Group AF" mode allows you to capture focus quite quickly, but no one really measured whether it is faster than 9-point dynamic focusing. Perhaps the latter in some situations will be faster.

Another important fact to pay attention to is that when we turn on the group auto focus mode when focusing single frame AF— S, the camera turns on the face detection function and tries to focus on the eyes of the person closest to it who stands out from the group. For example, if we are photographing someone standing between the branches of a tree and foliage, the camera will always try to focus on the subject's face, instead of focusing on the leaves. .

Unfortunately, face detection is only possible in AF-S mode, so if we're photographing a group of fast-moving athletes and we need the camera to lock focus and follow the faces of the subjects (rather than focusing on nearby objects), we'd better use the "Dynamic" mode. AF" for Nikon or "AF Point Expansion" for Canon cameras.

Here is a schematic comparison of each of the auto focus modes for Nikon cameras.

When viewing images clockwise: Single-point AF, Auto-area AF (9, 21, and 51), 3D Tracking, and Group AF.

3.5 Other focus area selection modes

Latest DSLRs have new area selection modes such as Face Priority AF, Wide Area AF, Normal Area AF, and Subject Tracking AF. These modes are used when shooting video on a SLR camera. Most likely, these functions will be built into the entire model line. Nikon DSLRs capable of shooting video. We will not discuss these modes in detail, since their functioning in different cameras is slightly different and may be changed in the future.

Canon also has its own AF area selection modes such as “Spot AF” where we can fine-tune focus within the focus point. This mode is highly specialized, it can be found, for example, in Canon EOS 7D cameras.

3.6 When to choose one or another type of auto focus

Why do we need to know how and when to use the different AF area selection modes? Because each of them can be combined with the focus mode! To better understand this, let's make a table with examples (for Nikon SLR cameras).

AF area selection mode	Nikon focus modes
Single point AF	The camera focuses only once and only on the selected focus point.	The camera focuses on one selected point, when the object moves, the focus is reconfigured.	The DSLR detects whether the subject is moving or stationary and automatically decides which mode to use: AF-S or AF-C. In either case, only one point applies.
Dynamic AF	Disabled, just works like single point auto focus.	We choose an initial focus point, and once the camera is on the subject, the surrounding points are turned on to track its movement. You can select the number of auxiliary points in the camera menu.	As in the previous case, but by a group of points.
	As in the previous case	Instead of using a specific number of focus points, all possible ones are used and color recognition is used to track the subject. The photographer specifies the starting point, and the camera follows the subject across the frame automatically, allowing him to recompose the shot without losing focus on the subject.	Similar to the previous
	The camera activates 5 focus points and aims at the nearest subject. If he determined that there is a person in the frame, he will focus on him.	The camera automatically focuses on the nearest subject and tracks it into the frame as long as it is close to 5 points. Face recognition doesn't work.	Not available.
Auto-area AF	The camera itself chooses a point depending on what is in the frame.	The camera itself sets a point on a moving object and follows it.	Similar to previous cases.

Note to the table of explanations of the focus area selection modes above: certain options may not be available in different models.

3.7 Changing focus area selection modes

To understand how to change the focus area selection mode on your camera, it is better to read the instructions. For entry level DSLRs like Nikon D3100 or Nikon D3300, you need to enter the “Shooting Menu” section, and advanced cameras have a switch on the back. Here, for example, is what the auxiliary display looks like on Nikon D600 and D610 SLR cameras.

We press the AF button at the base of the mount, and without releasing it, rotate the front and rear control wheels.

4. Autofocus scenarios and examples

Well we've learned a lot technical information about what each of the auto focus and AF area selection modes are. Let's go through more scenarios and look at examples to better understand and assimilate the data presented earlier. The camera settings described below are taken from Nikon cameras.

4.1 Scenario #1 - Filming outdoor sports

What autofocus mode and type of AF area metering will we choose when photographing, for example, football? Let's start with a choice correct mode focus. Obviously, single-servo AF-S won't work, as we want the camera to focus continuously as long as the shutter button is half-pressed (or whatever button we've assigned to AF). Therefore, we must use either AF-C or AF-A mode. Professionals want to take full control of the shooting process, so they switch to AF-C continuous-servo autofocus in such a situation.

What about AF area selection? Should we enable Single-point AF, Dynamic AF, Group AF, or 3D Tracking? Professional photographers shooting sports like football, basketball, or outdoor hockey will turn on 3D tracking, allowing the camera to watch the athletes while the person is composing the shot. If it suddenly turns out that 3D tracking is not working correctly, making mistakes often, then you can switch to "Dynamic AF" with a sufficiently large number of focus points, especially if we are standing close to the scene. Group AF will only work well if we are standing very close to the subject. Here is a set of focus mode settings for the described cases:

1. Auto focus method: AF-C
2. AF area metering mode: 3D Tracking, Dynamic or Group AF
3. Custom Settings => Dynamic AF: 21 or 51 points
4. Custom Settings => AF-C Priority Selection: focus priority

4.2 Scenario #2 - Shooting people on the street

When we photograph people posing for us in nature on a sunny day, any of the focus modes should work well. If we chose AF-S, the camera will focus once as soon as we half-press Shutter, so we just need to make sure our subject doesn't move after focusing. By default, the camera will not allow you to take a photo in single-servo AF-S mode if the focus is not achieved.

If, however, we shoot in AF-C continuous focus mode, then we just need to make sure that the focus is correct before pressing the button. Also, AF-A is good for shooting portraits.

As for selecting the AF metering area, it is more convenient to shoot with "Single-point AF" because the subject is stationary.

1. Modeautofocus: AF-S, AF-C or AF-A
2. AF metering area: single point
3. User settings => Priority selection for AF-S: focus priority
4. Custom Settings => AF-C Priority Selection: release priority

Probably not worth mentioning that we should always focus on the nearest eye of our model, especially if she is close to us.

4.3 Scenario #3 – Shooting portraits indoors

Photographing people inside a building in poor lighting can be a little tricky. If the room is dark, you can switch to AF-S single-servo focus mode so that the assist lamp will help us if necessary. If we have an external flash, the AF-S mode will turn on the red beam to adjust the focus.

In AF-C mode, this function cannot be used. And the AF-A autofocus should do the job, too, but professional photographers will prefer to turn on AF-S.

As for AF area metering, it is more convenient to use the center focus point for greater accuracy in low light conditions.

1. Autofocus mode: AF-S
2. Measurement: Single point AF
3. User settings => Priority selection for AF-S: focus priority

4.4 Scenario number 4 - photographing birds on the fly

Shooting birds is an extremely difficult genre of photography because it is difficult for us to predict their behavior and they often fly very fast. As noted above, when hunting it is better to select the Continuous Tracking AF (AF-C) mode, and the focus area is either Group AF or Dynamic AF from the 9th or 21st (I would like to take pictures at 21 points , but usually 9 pieces is faster). Professional photographers say they've tried 51 focus points and 3D tracking, but these modes are slower and less accurate than with fewer points.

One of the photographers told me that in 99% of cases he focuses on the birds on the central point, changing it only when the birds are sitting high on some branch. Once again, the central focus point will give the best result in most cases. If we are shooting small birds and there is no time to set the initial focus point, we can try the Group AF mode (if available on your camera).

1. Autofocus mode: AF-C
2. AF area metering: Dynamic or Group AF
3. Custom Settings => Dynamic AF: 9 or 21 points
4. Custom Settings => AF-C Priority Selection: release priority

4.5 Scenario #5 – Shooting landscapes and architecture

For these types of shooting, all focus modes are suitable, but it is more convenient to use AF-S, since we do not have objects to follow.

In poor lighting conditions, we will not be able to use the AF-assist illuminator function, because the distances are very long. In this case, you can mount the camera on a tripod and switch to Live View in order to focus on the bright object of our scene with a contrast method. If this does not help, one thing remains: turn off auto focus and focus manually.

When shooting landscape or architectural objects, we need to be more attentive to what our camera is focused on and remember that the need for a clear understanding of what depth of field (DOF) and hyperfocal distance is of particular importance.

One thing can be said about the AF area metering: we definitely need the “Single-point AF” mode to focus exactly on a specific point in our frame.

1. Autofocus mode: AF-S
2. AF area selection method: Single point AF
3. User settings => Priority selection for AF-S: focus priority

4.6 Scenario #6 – Shooting Large Animals

On a photo safari, when shooting large animals, professionals prefer to use the AF-C continuous focus mode and the Dynamic AF or 3D tracking AF area metering method, both of which work perfectly. Animals are usually not as nimble as birds (although sometimes they can move even faster), so if we are shooting non-fast action, it is better to use the Dynamic AF mode with more focus points or apply 3D tracking.

1. Auto focus mode: AF-C
2. AF area selection: dynamic focus or 3D tracking
3. Custom Settings => Dynamic AF: maximum amount dots or 3D
4. Custom Settings => AF-C Priority Selection: release priority

Hopefully, the scenarios listed above will make it easier to understand when and how to choose one or another focus mode and focus area metering. Now it's time to return to the table above and check if we understood everything well.

4.7 Scenario #7 – Photographing small groups

Beginners often ask what mode to focus on when we shoot a group of several people. Before talking about autofocus mode, there are some important things to discuss. If we are using a standard focal length lens or a wide aperture telephoto lens, we need to keep in mind the distance to the subject. When we stand close to our group and shoot at f/1.4-f/2.8, it can happen that only a couple of people are in focus, and the rest are blurred, unless they are standing in the same plane. There are two solutions here: either stop the aperture to f / 5.6 or f / 8, or move further away to increase the depth of field. Or you can use both of these tips.

If we want to blur the background and shoot at a large aperture, we can only put everyone in a row, strictly parallel to the camera. Imagine how it would be necessary for people to stand if they pressed their heads against a flat wall - this is how our models should be positioned.

As for the focus modes, in the daytime they will all work well, but it is more convenient to use a single point focus.

1. Modesautofocus: AF-S, AF-C or AF-A
2. Measuring method: Single point AF
3. User settings => Priority selection for AF-S: focus priority
4. Custom Settings => AF-C Priority Selection: release priority

Note: As you can see, in all modes, the priority selection for “AF-S” and “AF-C” is set to “focus priority” and “release”, respectively. And that's why. By setting the single-servo focusing mode to AF-S and “focus priority”, we tell the camera not to allow a picture to be taken if it could not focus. Professional photographers don't use AF-S very often, but when they do, they want the shot to be sharp.

For AF-C continuous-servo autofocus, "release-priority" works great in most situations: the camera adjusts focus as closely as possible, but doesn't allow too long shutter lags, allowing the photographer to shoot when they want to. It makes no sense to think for the AF-C mode about what priority to set: release or focus. In "shutter priority" the camera is not worried good focus or bad (why then do you need autofocus?), And in the "focus priority" it will not allow you to do nice shot until the focus is locked. If we need the focus to be this precise, we switch to AF— Sthen. Just set this parameter as shown in the examples above and forget about them forever .

5. Tips for improving autofocus performance in low light

As noted earlier, for good sunny conditions shooting, cameras do an excellent job with auto focus. But when photographers start shooting in low light, they face a lot of problems, especially when shooting indoors. Here are some tips to make the autofocus system work better when there is not enough light:

1. Using the center focus point. No matter how many focus points our camera has 9 or 51, we still focus on the center, and not on the extreme ones, if we shoot in bad light, because it works more accurately. There is usually a cross sensor in the center, which works better than any other points in our camera.

But then what to do with framing and composition if we have to focus on the center point? The solution seems to be to reassign the autofocus function from the "shutter" button on the camera to another one located on the back of the camera. Then you can focus on the subject and recompose the frame. Most DSLRs, including entry-level ones for beginners, allow you to do this. Professional DSLRs have a button (usually called “AF-On”) that can be enabled through the menu by selecting “AF-ON Only” in the autofocus activation settings. But we have to be careful after recomposing the frame, especially when shooting with a small depth of field at an open aperture. When we focus and then move the camera, the focus will definitely shift, and we need to be careful to keep our subject sharp.

2. Turn on the autofocus assist light function on the camera or on an external flash. Whenever you have to shoot in low light, this feature helps photographers. To activate it, you need to make sure that the AF-assist illuminator is turned on in the menu and the focus mode is set to Single-servo focus - AF-S.

3. Selecting contrasting objects and faces. Instead of trying to focus on a flat, monochrome surface, look for "contrasting" objects that stand out from the background.

4. Add some light or turn on lamps. Sounds simple, but if we're having trouble focusing, what could be easier than adding a little more light or turning on more lights in the room? One professional photographer told how he had to shoot dances at a party. There was so little light that I had to shine a flashlight on the models to focus. Then he approached the organizer and asked to turn on general lighting in the hall - all the problems were solved by themselves, and he was able to take excellent photos.

5. Keeping track of shutter speed. We may think that we have problems with focusing, but we should not forget that the shutter speed should be sufficient for handheld shooting. Details about the rule for determining the exposure time using the formula B=1/(2*FR) are described in a separate photo tutorial on DSLR settings.

6. Using a tripod. By using a tripod, we can achieve more precise focusing in poor light without having to worry about camera movement.

7. Let's use the contrast focus feature in Live View. With the camera on a tripod, we can try focusing in Live View mode, which, as we remember, can use a more accurate method of focusing on the contrast of objects in the frame. Many professional photographers find that whenever they have to shoot with a tripod, they try to use contrast focusing because it gives the best results. And, in general, it is more convenient to focus in Live View mode, since the image on the camera screen is larger than in the viewfinder.

8. Useful thing- bright flashlight. If our camera model does not have a built-in autofocus assist lamp, we use a bright flashlight and ask someone to shine on our subject to try to focus. As soon as the sharpness is caught, we switch to manual focus mode and turn off the flashlight, take pictures “with self-timer”. I met the advice of professionals to use a laser pointer to focus when shooting night landscapes (do not forget that if you get into the eye of a person or animal, you can burn the retina).

9. Using manual focus. Such advice does not correspond to the title of the article, but we must be able to manually focus and not be afraid to do this. Sometimes manual focusing will turn out even faster than in automatic mode. Many landscapes, macro shots, and architectural photographs are taken with manual focus.

Photo 13. Another landscape shot with manual focus. HDR of three frames. Camera Nikon D610. Lens - Samyang 14 / 2.8. Tripod Sirui T-2204X.

P.S. Dear friends, colleagues and guests of the site! If you think that the article can be useful to other photographers, I will be grateful if you share a link to it on social networks, on specialized forums, and publish it on your blog. Just ask to put an active link to the source! The wife spent the whole day to draw all these frames on the photographs ... It is impossible that her work was in vain. Thank you! Good luck, sharp photos to you.

The most common complaints I hear from most photographers of any level are "my images aren't sharp" and "I can't get focus." Many people blame their equipment and, indeed, there are many cases in which the equipment is to blame. However, I have found that the vast majority of cases are simple user errors. They often boil down to a lack of understanding of how the autofocus (AF) system works. This article will give you a better idea of ​​focus and sharpness, and hopefully help you get photos you're happy with!

1. Adjust your diopters

What are mine, you ask? Your diopters - or your eyepieces. You will never know if a camera is well focused on a subject unless you can see for yourself what is in focus through the viewfinder eyepiece. On the side of the eyepiece (as shown below) there is a small wheel to adjust the focus of the eyepiece to suit your vision.

You can adjust the eyepiece to quite a large correction, but if you need even more correction, then interchangeable diopters are available for DSLR / SLR cameras from many major manufacturers in the range from -5 to +4. No, this won't help your autofocus work better, but it will help you recognize when it misses and correct the situation with manual focus.

2. Understand your viewfinder

What the hell do all these things inside mean? At this point, you might want to get the instructions (remember that paper book that came with your camera?). Most conventional DSLR cameras have 9-11 focus points. The best of the best, professional cameras can have from 45 to 51 points (although in fact you can only choose 11-19, the rest of the points are optional).

There are two types of focus points: co-plane and intersection points. Single plane points only work on contrast lines that are directly perpendicular (90°) to their orientation. So, if you're looking through your viewfinder like the one above, you'll see that most of the dots are rectangular, some are oriented horizontally, some are oriented vertically.

Points of the same plane will only work perpendicular to their orientation. So - let's say you were shooting a tree - a vertical focus point wouldn't be able to find the edge of the tree trunk, but a horizontal one would. You can use this to your advantage when choosing a focus point that will lock onto the line you want and ignore those you don't want to focus on.

Cross point focus points will work with lines of contrast placed in any way. Most cameras have a single focusing intersection point in the center, surrounded by points on the same plane. The newest cameras today contain intersection points at all focal points.

Each focus point also has a specific sensitivity. Most require a lens with an aperture limit of at least f5.6 to even use autofocus. On most cameras, the surrounding AF points are exactly this sensitivity, and the center point provides hypersensitivity if you are using a lens with an aperture limit of at least f2.8.

So if you're working in low light conditions, you can achieve better autofocus by using the center focus point. Even if you don't use an f2.8 lens, or better yet, there are no light restrictions to favor the center point, it can still give a more accurate result because it is the intersection point.

When we look at the focus point rectangles, it's worth remembering that the real area of ​​the sensor is 2-3 times larger than what is displayed. Keep this in mind as you focus. If you fix the focus on someone's bridge of the nose, remember that the person's eyes will also fall into the active area of ​​the sensor. Autofocus will lock on to the eye rather than the bridge of the nose because the eye has more edge contrast than flat lighting on the nose. Often this may not matter, but if you are working at a very shallow depth of field, you will feel the difference in which area of ​​the image is most sharp.

3. Lend a helping hand to your lens

Most autofocus systems have a certain amount of error or variance and can actually miss the point of optimum focus due to the mechanics and inertia of lens movement. You can minimize this effect by manually focusing the lens as close to the desired focus as possible, and then let the autofocus system finish focusing. Or, if this seems too difficult for you, at least let the autofocus make two attempts to achieve correct aiming. Half-press the shutter button to set the approximate focus, and then press again to fine-tune it.

The advantage of higher end lenses is that they allow full manual control even when autofocus is locked. Cheaper lenses do not allow manual focus adjustment after locking, although this good way make sure the focus is as perfect as it can be.

4. Find a good line

Autofocus systems work on contrasting lines, so they may struggle on subjects with low contrast (eg cheek or forehead, white dress or black tuxedo, sand, monochrome walls, etc.). In areas like these, autofocus can go all day long and never lock. The approach is to find the "best line" - it could be the eyes, the lines between the contrasting shirt and suit, between heaven and earth, the doorway. Anything with contrast will help autofocus work better and faster.

Weak focus zone

Best Area to Focus

5. Don't use all-point focus mode

Unless you're in a terribly fast-paced situation that requires incredibly fast aiming, it's best to avoid all-point focus mode. This mode doesn't know what you want to focus on and is usually fixed to whatever is closest to the camera. There are situations in which this is exactly what is needed, but they are few and far between.

6. Focus and recompose - but do it the right way

I'm used to focusing and recomposing using the center focus point all the time. I lock the focus and then recompose the shot. I once read a few articles that said you shouldn't do this - that you should use the point closest to the area you want to focus on. Theoretically, this is justified by the fact that during the movement of the camera, due to the movement of the lenses and the change in the angle value, the distance between the subject and the lens also changes.

If you use a focus point directly on the subject and do not recompose the frame, there will be no change in the distance between the subject and the lens, and therefore erroneous focusing. So, I decided to take some pictures to show you that it is - and it is not.

There was absolutely no advantage in using the nearest non-center point without changing the composition. In fact, focusing using the center point and recomposing was, indeed, more accurate in all cases except for one - macro. I took shots at all focal lengths from 17mm to 200mm and checked all distances from macro to 10 meters - with the same results.

Each test using the center focus point and recomposing the frame resulted in a sharper picture. Greater sharpness from using the center point and recomposing, less sharpness from using an outer focus point right on the subject. To clarify, the above theory is correct, in that you lose sharpness by moving the frame away from a fixed center point. What's not true is that using an outer point directly on the object will bring back sharpness - it won't.

I think there is a good chance that on my camera the center focus point is three times more sensitive than any of the other eight points, and it is this one that is most accurate. But so is the case with many cameras, with the exception of high-tech new models like the Canon 1Ds Mark III or Nikon D3X. Other possible the reason is that most lenses are sharpest in the center and lose sharpness towards the edges.

Here are three of the most typical examples of what I shot on two different cameras. An insert is an inscription on a scale of 100%.

Center focus point, no composition change. Lens 50mmf 1.8.

Lens 50mmf1.8. Central focus point. The camera is moved to the left after fixing the focus.

Lens 50mm f 1.8. Left focus point. Focus on the object.

What can I say - whether to switch the focus point or not, in my opinion, is a matter of time. But try it yourself, your result may differ.

A small note on macro - such shots should always be taken with a tripod and manual focusing, due to the extremely shallow depth of field and the proximity of the lens to the subject.

7. Use the correct focus mode

Most DSLR cameras have at least two similar focus modes. The first is "One Shot" (Canon) or "Single Servo" (Nikon). This mode assumes that the object is stationary. Focus locks, you get lighting confirmation on the internal display, and then you release the shutter. You will not be able to release the shutter if the focus is not locked.

The second type is “AI Servo” (Canon) and “Continuous Servo” (Nikon). This mode is suitable for shooting subjects in motion, including sports, wildlife, etc. The camera finds the subject using the focus point, and the focus will constantly change to keep up with the subject, but will never lock. The shutter button will work even if the focus is not perfect.

There are also other modes on some cameras, such as Canon's AI Focus, which are great when the subject is static but may start to move, as is the case with young children. Autofocus will lock on the subject, but if the subject moves, the camera will enter AI Servo mode to track it.

The third option, pre-focus, is for objects that are moving towards or away from you. The camera will try to predict the movement and give you an acceptable focus.

8. Don't change depth of field for good focus

Although using a larger depth of field with a smaller aperture can increase the "apparent" sharpness of an image, remember one thing: no matter what the depth of field is, there is only one point of focus. So always practice good focusing techniques no matter what depth of field you use.

9. Use a tripod or find a foothold

When we take a photo, we all unconsciously sway back and forth - in particular, leaning towards the subject with a heavy camera and lens kit. It `s naturally. Everyone has it to one degree or another. And if you're shooting with a very shallow depth of field, that small amount of distance you shift can have a big impact on the sharpness and the sharpness of focus you want. If you're using a 4" depth of field, a 2" offset can have a disastrous effect. So use a tripod.

Now I have to add, since I use a tripod myself - I hate them. They affect the way I work and, most of the time, the way I shoot. So, if you'd rather avoid using a tripod, at least take the time to practice being a good photographer. One foot in front of the other, legs slightly bent, arms pressed to the sides, not dangling in space (remotes can come in handy here remote control), and the weight of the body is distributed centrally over the legs.

10. If still unsuccessful - use manual focus

I hear a deep sigh every time I offer this to photographers. They regularly state, "I shoot only in manual mode, never on automatic." But offer them one more time manual focus, and they will look at you as if you just offered them to sell their children. Manual focus in most cases (given that your diopters are set correctly) will help achieve the best and most exact result. Especially in this digital age, when it's so easy to see an image at 100% or even 200% magnification on our monitors.

In fact, if you look at the unofficial autofocus specs, you'll notice that they aren't very accurate. Here is the specification for "sharpness": An image is considered sharp if it appears sharp in print 6x9 from a distance of 10 inches. Yep, that's it. No 100% zooms, no 20x30 prints. Just this.

Today, a number of new cameras are being produced with a built-in Live View mode. This can be a useful tool for manual focusing. Turn on your Live View, zoom in on the subject/focus point and check the sharpness on the display. This doesn't work very well in my case, as I'm almost always in bright environments: deserts, beaches, etc. - but for some it will work just fine.

One note about the image above. I usually use it to show the manual focus switch, but the other switch is also of interest: "1.2m to infinity" and "3m to infinity". This switch is related to what I was talking about earlier: don't make your lens hunt for focus through as much space as possible. If you know you won't be focusing on anything closer than three meters, move the lever to the appropriate position and the lens won't have to wander around looking for focus. This can result in more accurate primary auto focus.

11. What should I focus on?

For close-up portraits, the consensus is, in general, worked out: the eyes. For other types of portraits, it's still the face, unless you intentionally want to focus on some other part of the body. Focus precisely where you want the viewer's eye to go.

Landscapes aren't always easy, but you still need to stick to the rule mentioned above. Do not bet on the fact that "this is a landscape with a wide viewing angle, focus on infinity." If you have a subject in the foreground, focus on it and let your depth of field bring the image into the background. If the object in the foreground is not in sharp focus, it is confusing, because in natural conditions we usually see objects that are closer rather than distant ones.

I can now work with focusing at "Hyper Focal Distance", but that's out of the scope of this tutorial. If you are interested in this topic, which is likely, use a quick Google search.

12. Is the subject in focus, but is it sharp?

Focus and sharpness are two different things. Explaining the concept of sharpness can take another lesson of its own, so I'll just point out a few useful points.

If an image is out of focus, you cannot bring it back into focus by sharpening it. You will only get a very sharp out-of-focus picture. Most RAW images need some sort of sharpening. Whether you're using Smart Sharpen, Un-sharp masking, or high pass filtering techniques, most RAW images benefit from sharpness. However, as I gradually started using higher quality cameras, I saw less and less need for sharpening, and now I only use this tool in about 25% of my frames.

Remember also that sharpness depends on the final product. You won't sharpen in the same way on an image that goes to the web as you would on a 16x20 print. And with that in mind, if you intend to sell your photo through a stock agency, don't sharpen it at all. Most will tell you not to do this because you can't predict what the image will be used for and at what size.

On the left are images directly from the camera, unedited ("Straight Out of the Camera"), on the right - with added sharpness.

13. Consider exposure

Shutter speed is another setting that can lead to a lack of sharpness. Each person has a limit on the shutter speed at which he can shoot handheld on lenses with different focal lengths. Some people are more stable than others, but if you're shooting at a shutter speed that can't compensate for the movement (trembling) of your hands, your image will come out blurry. When it comes to standard and wide angle lenses, most people can shoot handheld with them consistently at around 1/30-1/60 of a second.

Larger telephoto lenses require much faster shutter speeds. General rule, which people start with: "1 to the focal length of the lens". So, if you have a 200mm lens, shoot at 1/200th of a second, and start from that level to understand your further possibilities. Personally, I'm shaking like California on its worst days, so I usually shoot for more short exposures. It also depends on how far away you are from your subject, as the farther you are, the more noticeable the movement.

If the subject is moving, keeping the camera stable or on a tripod won't help - you'll still need to choose a satisfactory shutter speed in order to stop the action. Most start at 1/250, but it depends on how fast the object is moving. The requirements also vary depending on whether you are shooting in a static position or following the subject. If the latter, you can choose more long exposure and also get some cool effects. This will allow you to show movement in the background, but will freeze the object itself.

Image stabilization systems on lenses allow you to shoot handheld at faster shutter speeds (up to 3 stops), but will not "stop" movement any better than a lens without an image stabilization system. You can only capture the action with a shutter speed (or high-speed flash).

Image not out of focus. The shutter speed is too long.

14. Choose the right exposure

Correct exposure and good lighting (the essence of all photography) is the key to good focus and sharpness. While sharpness is determined by the line of contrast, if you underexposed the frame or shot in dim light, the image will not be sharp even if all other parameters of good focus are met.

15. I did it all. I'm still out of focus!

There is a small chance that something is really wrong with your hardware. Third-party lenses are sometimes not very well designed, and therefore will not always work perfectly with branded cameras. Some work great, others don't. But sometimes even branded lenses are not made perfectly.

Cameras like the Canon 50D and 1D/Ds Mark III have excellent front- and back-focus fit for over 20 different lenses, so if you know one lens is perfectly focused in front of your subject all the time, you can adjust the camera. to fix it. If this option is not available, you need to determine if your lens, or both lens and camera, needs repair.

Here's a test you can do at home to see if it's you or the camera. Find a ruler and place it on the table away from the camera. Put the camera on a tripod and open the aperture as wide as possible. Take a picture of the ruler at a 45-degree angle, focusing on a specific mark - in this example, the six.

If this is the mark that you will see as clearly as possible when you open the image, then everything is in order with your equipment - get back to working on your technique! If the sharpest point is before or after this mark, then you will know that this is a hardware problem and should be taken to service.

16. Conclusion

I covered a lot of questions in this tutorial - great that you read to the end! It seems to me that good focus and sharpness are two of the most important technical parameters that must be preserved in an image. This can make a difference between shots that look professional and those that look like amateur work (and we all want to look like professionals - whether we are or not).

Please feel free to leave your opinion in the comments - have you ever had problems with focus and sharpness?

To understand which autofocus mode to choose, you must first understand what you are photographing. Autofocus modes and settings on all cameras are about the same. They may differ in name and be managed differently, but the principle is the same everywhere. So what is autofocus?

First, make sure you have autofocus turned on. On advanced cameras (Nikon / / D7000 / D7100) there is a separate switch on which there is an M mode (manual focus) and some other modes - different autofocus, or just AF.

The M (Manual) mode works the same way cameras did in the 50s, that is, without autofocus. If you do not have such a switch, then the autofocus modes on your camera are controlled through the menu.

In addition, autofocus lenses with a built-in motor (AF-S) also have an autofocus switch, very often marked M / A - M. Make sure that the lens is not in manual mode either. Do not confuse the AF-S lens type with the AF-S autofocus mode, they are different things, although they are called the same thing.

Autofocus modes are as follows:

AF-A (Auto). Automatic mode, in which the camera decides for you how to focus. If you are not sure which mode you need, choose the automatic mode.

AF-S (Single). Mode for static scenes. In this mode, the camera focuses once when you press the shutter button to the middle, and that's it. The camera no longer focuses until you release the button. Great for landscapes and portraits.

AF-C (Continuous). Tracking mode, where the camera constantly follows the subject and adjusts autofocus continuously until you release the shutter button. Turns on when you press the shutter button halfway. This mode is great for photographing wildlife, sports, and fast-moving children.

In the Custom Settings Menu, in the Autofocus section, you can find AF-S / AF-C priority selection.

Release is the shutter release immediately, even if the image is not at all in focus. I hardly remember ever having sharp shots in this mode.

Focus- The shutter only works when the image is strictly in focus. This is very slow and you risk missing a frame.

I recommend value release+focus for AF-C, it's something in between. Even if the first frame is out of focus, the next ones will be much better in continuous shooting. In this case, you will not lose the first frame, although it will be a little blurry. Focus is good for AF-S because nothing moves in the frame.

In addition, you still have to choose the type of autofocus area.

Nikon usually offers three options:

Conditionally, the areas can be divided into two types:

Multiple sensors (AF-Area). Focus information comes not only from the sensor you have selected, but also from the surrounding points, and the surrounding sensors are not highlighted in any way. For example, on the Nikon D7000, you can select a zone from 9, 21 or 39 points. Usually, the faster something moves in the frame, the more area is required. To be honest, I don't use these zones, I prefer 3D-tracking.

3D tracking. This mode can be on some models along with a white rectangle and a crosshair, on other models somewhere else, for example, when choosing the size of the autofocus area. As the name implies, this is a tracking mode, and when tracking, not only the distance to the object is taken into account, but also the color. You choose a focus point, autofocus clings to what is under this sensor, and then starts to follow it if the subject moves or you turn the camera.

The fundamental difference between AF-Area and 3D-tracking is that in the first case, the camera focuses on what falls into the selected autofocus area, and in the second case, the camera itself moves the area behind the object, switching autofocus sensors. Therefore, in 3D mode, it is very convenient to focus on something specific, then move the camera to frame it differently, but autofocus will still focus on what it was aimed at initially. This differs from the AF-S mode in that AF-S is not aware if the object moved further or closer during framing, or even flew out the window.

In addition, 3D tracking can even replace single focus point selection. Instead of going through the points with the selector until you get to the one you need, you can simply visit the center in 3D mode and then crop it as you need, while the camera will keep focus on the object, moving the focus point, switching autofocus sensors. The object, at the same time, will not be able to escape from autofocus.

Keep autofocus in auto mode (AF-A, white rectangle), this mode will work fine in most situations without your help. If the work of autofocus did not suit you in any particular case, then start thoughtful settings.

That's all autofocus.

What should you do if you get fuzzy footage on a regular basis? Is the technique to blame or is it your actions? This article will help you figure it out. In it, you will learn how to check the focusing system of the device for accuracy and adjust it to get sharp shots.

Nikon D810 / Nikon 85mm f/1.4D AF Nikkor

I would like to say right away that in most cases it is not the camera that makes the mistake, but the person working with it. So, for starters, it’s worth looking for the cause of errors with focusing in your own actions with the device. In recent tutorials, we talked about how to work with different autofocus modes and focus points. This knowledge will help you in practice. It will also be useful to read an article on how a novice photographer can evaluate and improve the quality of their own work.

Autofocus can fail when working in low light, and when shooting complex, diverse shots (the camera will not know what to focus on). Such focusing shortcomings can be avoided by simply setting the device according to the shooting conditions. For example, choosing the AF-C constant focus mode and 3D subject tracking when shooting sports will allow you to get much more sharp shots than working with single focus. But there are focus errors that occur systematically, regardless of the shooting conditions.

Back and front focus

In SLR cameras, the phase type of autofocus is the main one. It is with him that you are dealing, working through the viewfinder of the camera. Phase focusing occurs using a separate sensor installed in the camera. As you can see, this is a complex system, and sometimes it can work inconsistently.

The consequence of this will be systematic autofocus errors, called back- and front-focus. In the case of back focus, the camera constantly focuses not on the subject being shot, but behind it. In the case of front focus, on the contrary, the camera constantly focuses in front of the subject. Please note that the presence of back- and front-focus can only be said when the camera makes a mistake with focusing every time in the same direction. If one frame is sharp and the other is not, then the problem should be looked for elsewhere.

Back focus: the focus was made on the face of the girl, and the sharpness ended up behind her, on the fence.

The problem of back- and front-focus is especially terrible when working with high-aperture portrait optics. There, the depth of field will be very small, therefore, any, even minor focusing errors will be very noticeable in the photo. For example, the sharpness in the frame will not be in front of the model, but on the ears.

On the other hand, if you are a happy owner of a whale lens or universal zooms that do not shine with high aperture, you can sleep peacefully. After all, even if your camera has back or front focus, you most likely will not notice it, because focusing errors will be compensated by a large depth of field.

Contrast autofocus

In a SLR camera, in addition to phase focusing, there is another type of autofocus - contrast. You activate it by turning on the Live View mode and sighting the picture through the screen of the device. With contrast autofocus, there can be no back and front focus, since it does not require separate sensors for its operation, focusing passes directly on the matrix. Thus, if phase focusing regularly "smears", try switching to Live View mode and working with contrast autofocus. It works a little slower, but gives more accurate results.

Checking Focus Accuracy

How to check the camera for back and front focus? An accurate conclusion about the presence or absence of these shortcomings can only be given by an authorized service center of the manufacturer of photographic equipment. However, the photographer can make a preliminary assessment of the focus accuracy for himself.

We propose a simple algorithm for such verification.

First, let's prepare the camera.

1. Insert the battery and memory card into the camera. Turn on the camera.

2. Check if autofocus is enabled.

On entry-level models (such as the Nikon D3300 and Nikon D5500), autofocus is enabled by a switch on the lens. It should be in position A.

On advanced cameras, there is a switch on both the lens and the camera. The letter M stands for manual (Manual) focusing. The abbreviation A (Auto) or AF (Auto Focus) stands for auto focus. Both switches must be in the appropriate position to enable auto focus.

3. Press the Menu button, in the "Image quality" item, select "JPEG high quality". If you know how to work with RAW, you can use this format.

4. Turn on A (Aperture Priority) mode. If you know how to work with manual mode M, you can use it. Open the camera aperture to the maximum value. Everything is simple here: the smaller the number indicating the aperture, the more it is open. In case of whale lens you will most likely have to deal with an aperture value around F5.6.

5. Set the minimum ISO value. This is usually ISO 100 or 200. This will ensure that test shots are clean and free of digital noise.

6. Now - the most important thing! Let's select the focus mode on one point. It may be called "Single-point AF" in the camera menu.

On entry-level cameras (Nikon D3300, Nikon D5500), autofocus area modes are selected through the menu called by the i button. In the corresponding paragraph, you just need to choose the best option.

On advanced Nikon cameras (starting with the Nikon D7200), autofocus area modes are selected as follows: hold down the button combined with the AF / M switch and turn the front control wheel. In the information display, you will see how the focus area modes change.

7. The point is small - download and print a special target on any printer to check the accuracy of focusing.

There are targets different kind, but the proposed option is perhaps the most popular. In principle, you can check the focus, say, using a regular ruler (how it will become clear later), but it is much more convenient to do this on a target.

Checking autofocus

So, the camera is set up, the test target is printed. It's time to act!

• The camera is best mounted on a tripod.. Without a tripod, such a check will be extremely inaccurate and indicative.
• Provide adequate lighting for shooting. It is best to shoot by the window during the day. You can use a flash (both built-in and external).
• Place the target on a flat surface, and position the camera at an angle of 45 degrees to it at such a distance that the target occupies a significant area of ​​the frame.
• Choose the center AF point. Focus exactly on the target - on the inscription Focus Here (Focus here). A thick black line with this inscription should be located in your frame strictly perpendicular to the optical axis of the lens.

• Take a few shots. Do not use continuous shooting, focus again after each frame. Remember that after focusing, in no case should you move the camera, change the shooting distance. If you are using a zoom lens, test it at different focal lengths. I note that it is most convenient to conduct testing from a focal length of around 50 mm, and you can start with it.
• View received footage. To see them better, do it not on the camera screen, but on the computer monitor. If you see a systematic focus error on all frames, then most likely you have detected back or front focus. It's not worth worrying about this. This is easily fixed in the service center. And owners of advanced cameras (starting with the Nikon D7200) can adjust the focus directly from the camera menu

Precise autofocus performance. Back- and front-focus are absent.

Front Focus: Sharpness was closer than expected.

Fine tuning autofocus

Advanced cameras (starting with the Nikon D7200) have an autofocus fine-tuning feature that will help you get rid of problems with back and front focus, fine-tune the focus system. The convenience of the function is also in the fact that the device remembers the settings separately for each specific lens. Let's say a bug shows up with one of your lenses. You can make adjustments specifically for him, and they will not affect the work with other lenses. When you attach a lens to the camera, it will automatically apply the appropriate corrections for it. Please note that autofocus fine-tuning will only work when focusing through the camera's viewfinder (with phase focusing). When working through the Live View screen, it is not activated, and there will be no need for it, because in this case a contrast type of autofocus is used, which eliminates problems with back and front focus.

Let's see how the autofocus fine-tuning feature works.

Let's find the item "Fine tuning AF" in the camera menu.

Autofocus Fine Tuning Menu in Nikon D810

The first item on this menu, as the name suggests, allows you to enable or disable this feature.

The default menu item allows you to enter the AF fine adjustment value to be applied when no separate adjustment has been created for the lens attached to the camera. It makes sense to make such a setting if the device systematically makes the same mistake with focusing with all lenses.

The last item - "Display saved values" - allows you to see all the corrections stored on the camera for various lenses. You can make an autofocus setting for each lens you have, and it will be saved on the camera. Through this menu you can see all the adjustments you have made. In the same paragraph, you can delete unnecessary settings. It is possible to enter your own ID (from 00 to 99) for each lens. This is useful if, for example, you are using two identical lenses and you have made an autofocus setting for each of them. Such an identifier will help you distinguish them from each other in this menu.

The most important menu item is "Saved value". It shows which fine tuning value is applied in this moment and gives you the option to change it. Once in this menu item, you can fine-tune the operation of AF with a specific lens (installed on the device at the moment).

Fine tuning autofocus

To make the necessary adjustments, you first need to take and examine test shots (as described above). If on the test frames the focus is behind the object, you need to make a negative correction, and if in front of the object - a positive one.

The difficulty lies in determining the desired amount of adjustment. You can find the optimal value using test frames. After making the approximate settings, just take a series of test shots and check if the lens is now exactly in focus. If not, make appropriate corrections.

One of the significant problems for many beginners, and even quite experienced photographers, is achieving the desired sharpness of the resulting images. "Get in focus" sounds very simple, but in practice this action can be a little more difficult.

On the one hand, there are many ways to get a photo in focus. What is the best method to choose and how exactly to use it to achieve the desired results? Let's take a look at some of the most common and effective ways camera focus.

One-Shot AF

One of the most simple ways The focus of the camera is to use One-Shot AF, which in most cases is the default setting and one of the most effective ways to photograph.

In single frame mode, you simply aim the camera at the subject and press the shutter button halfway.

This locks focus on the subject, allowing you to recompose the image if necessary without losing focus. This technique is called focus and recomposition.

For example, in the image above, if you want the bridge to be in focus, you need to position the center AF point on the bridge and press the shutter button halfway.

You will then compose the shot as you see above and press the shutter button all the way down to take the photo. As a result, you will get the subject in focus even if you have recomposed the photo.

This option is good for landscape photography or still subjects.

Continuous autofocus

Obviously, there are no perfectly still objects, so you need a focusing tool that allows you to track moving objects while keeping them in focus.

In this case, continuous autofocus can come to the rescue. All you need to do is to capture the subject with the viewfinder, press the shutter button halfway and follow the subject as it moves while holding the shutter button halfway down. This will continuously adjust the focus (hence the name).

Most entry-level cameras require you to use the center point for continuous AF, but if your camera is higher end, you can determine which AF point is used to track a moving subject.

Naturally, this type of focus is best for shooting, for example, wildlife or where you need to quickly adjust the focus.

Face detection autofocus

Not all cameras have face-detection autofocus, but if it does, it's a valuable tool for portrait photography. It uses algorithms to recognize shapes that resemble human faces.

In Live View mode, you can see the focus on the face as you work as a frame around the face.

All you have to do is press the shutter button halfway to indicate the area you want focus on and then take the picture.

Focus point selection

Regardless of which AF mode you use, you need to have an active AF point on your subject. Otherwise, the object will not be sharp.

Generally, there are two ways to select an active AF point: select it yourself or automatically using the camera. Most cameras these days are pretty good at picking the right AF point for most situations. But it's still not always perfect.

In situations where time is of the essence, such as portraiture or landscape photography, try choosing your own AF point. See your camera's User Manual if you don't know how to do this.

However, be aware that your lens will focus best when using the center AF point. If you use a different focus point, the image may not be sharp enough.

Back button focus

Another way to get the image in focus is to use back button focus. Depending on the particular camera, you may have an autofocus button on the back of the body that you can press all the way down to focus on the subject.

This is beneficial for a number of reasons, including preventing you from accidentally pressing the shutter button and therefore taking a photo before you (or the camera) were ready. When shooting moving or multiple subjects, back button focusing also allows you to focus on your main subject. In other words, releasing the autofocus button prevents the camera from focusing on the new subject, and you can still take photos with focus on your main subject.

Manual focus

The manual focus process may vary slightly depending on the specific camera or lens, but the following steps are basically standard:

• find the AF-MF switch on the lens and move it to the MF position
• rotate the focus ring on the lens until you see that the desired subject is sharp
• using Live View, zoom in on the subject to check its sharpness. Adjust with the focus ring if necessary.

That's all!

Manual focusing can take a little longer than auto focusing, but it works better in a wide variety of situations, such as macro photography when you're shooting through something (say, using a plant in the foreground to frame a subject in the background), subjects in crowded places (street scenes), and in low light situations. In other words, in situations where auto focus "resists", don't be afraid to switch to manual.

hyperfocal distance

A more complex and technical method for obtaining focus is to calculate the hyperfocal distance. Basically, it means that you should use the depth of field calculations for the lens you are using to find the closest point in the picture where you can still get acceptable sharpness.

Finding this point will allow you to focus on the spot that will give you the best depth of field and maximize the area of ​​field in your photo.

There are several ways to determine hyperfocal distance, but the simplest among them are the following:

• focus on one third of the bottom of the frame. Since the depth of field extends to about twice the focal point, focusing on that third will help you maximize the depth of field;
• You can use a smartphone app such as HyperFocal Pro for Android (shown above) or Digital DOF for iOS devices, which will save you from having to do any math.

If you are a landscape photographer, using hyperfocal distance will be especially useful for you.

Focus stacking

The final method, which we will cover in this article, of obtaining perfect focus in photographs is the use of the Focus stacking method, which is achieved through post-processing.

Essentially, you take several different photos, each with a different focus point (i.e. focus on the foreground, middle, and background) and combine them together into one image in post-processing. The resulting composite photo will be sharp from foreground to background.

This method is especially useful for macro and still life photography, and is also good for landscape photography.

A word of caution about the Focus stacking method: there can't be any movement in the snapshot.

This is because you are taking multiple exposures at different times, so if something in the frame is in motion (such as a tree due to wind) it will cause ghosting. Anything that moves in the photo will be blurry.

Another complication with this method is that you need to adjust the focus for each shot without disturbing the camera position. Otherwise, the frames used will not match perfectly in post-processing.

So, now you have a number of methods that will help you adjust the focus on the subjects you are shooting. It will take time to master them. However, it's definitely worth it. Take action!