Camera focus modes. How to select the desired AF area mode? Other Focus Area Selection Modes

Publication date: 10.10.2015

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.

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 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.

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: what less number, indicating the diaphragm, the more it is open. In the case of a kit lens, you will most likely have to deal with apertures 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.

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

There are different types of targets, 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).

Put the target on 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

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.

Focus modes

The focus mode that everyone usually works in is One Shot AF. It suits any static scene, and sometimes slow moving objects. When you shoot in One Shot AF, you compose the scene using the viewfinder and press the shutter button halfway. The autofocus system turns on and the lens focuses directly on the main subject. At this stage, a green light will light up to confirm focus, and you can also hear an audible confirmation.

Once the camera has set a focus point, it locks it. If you don't release your finger from the shutter button, the focus will not change - even if you move the camera. This useful feature called "Focus Lock". It allows you to first focus on some point outside the scene, and then turn the camera around and compose. For example, imagine you are photographing a landscape. The camera may want to focus on the furthest hills, and you want to increase the depth of field by focusing on a point that is closer to the camera. All you have to do is tilt the camera down a bit to bring this dot into view. Now press the shutter button halfway, make sure the camera has focused (the green confirmation light will turn on), and keep the shutter button half pressed as you compose your scenery.

The One Shot AF mode has another useful feature. The camera will not let you shoot if the lens is out of focus. If the focus confirmation signal flashes, it means that the lens failed to focus and nothing will happen after pressing the shutter button completely.

Shutter button

The shutter button on your EOS camera is actually a two-position electrical switch. Partially pressing the button activates the first switch (Canon calls it SW-1). After the first press, the autofocus and metering systems turn on. In low light conditions (depending on the selected shooting mode), the built-in flash may pop up. To help the camera focus in low-light conditions, the AF-assist beam may light. Pressing the shutter button fully activates the second switch (SW-2) and starts the following chain of actions:

the mirror inside the chamber is lifted up to allow the light to reach the rear of the chamber
the shutter mechanism starts - the shutters open and the film (or digital sensor) begins to receive a light flux
if the built-in flash is raised or an external Speedlite is attached to the camera and turned on, the flash fires
the mirror returns to its original position
the shutter returns to its original position and is ready for the next exposure

AI Servo AF Mode

AI Servo AF is essentially One Shot AF, but without focus lock. The lens automatically refocuses every time the distance between the camera and the subject changes. This feature is very useful when photographing moving subjects. This mode is most often used in sports photography. However, they must be used with caution. In this mode, you can take a picture even when the lens has not yet focused or failed to focus. In addition, if a moving object appears between the camera and the subject, the lens may focus on an object that is closer to the camera. All this can lead to out-of-focus images.

In AI Servo AF mode, the green focus confirmation light will not light up, and you will not hear a confirmation beep (even if it is turned on). However, in both One Shot AF and AI Servo AF, the green light will blink if the camera is unable to focus on the subject.

There is a slight delay between lens focusing and shutter release. Although it is measured in fractions of a second, it can be taken into account when shooting fast-moving objects - for example, a racing car at a speed of 160 km/h travels about 4.5 m in 1/10s. This means that while the machine may have been in focus when the shutter button was pressed, it may not be in focus when the shutter itself opens.

Many EOS cameras solve this problem with predictive focus technology. The camera measures the distance to the subject every time the lens is refocused. By analyzing this data, the camera can calculate the speed and direction of the object. It then extrapolates this information to determine where the subject will be when the shutter is released. The camera then refocuses the lens to the calculated distance so that the subject is in focus at the moment of exposure. The predictive focus mode is activated automatically when it is needed.

Custom Function

In One Shot AF mode, half-pressing the shutter button activates the autofocus system. Once the camera has focused, it will keep that focus as long as you keep pressing the shutter button. This means that you can focus on an arbitrary point, and then you can turn the camera and compose the scene without changing the focus.

Focus lock is effective when the main subject is not well lit or has insufficient contrast for the lens to focus on. In this case, you focus on any other subject at the same distance from the camera as the main subject.

Focus lock mode is not available in AI Servo AF - the lens will constantly refocus as you move the camera. However, setting CF 4-2 on the EOS 1N and 1V cameras allows AI Servo AF to be paused by pressing the AE Lock button.

AI Focus mode

The third focus mode - AI Focus - is actually a combination of the first two. Most of the time the camera is in One Shot AF, but if the focus sensor detects that the main subject is moving, the camera will automatically switch to AI Servo AF and start tracking the subject.

How does the camera determine that the subject is moving? As soon as we half-press the shutter button, the focus sensor starts to work constantly. If the focus distance changes, the camera determines that the subject is moving - and can determine the speed of movement. As soon as this speed exceeds a certain threshold, the camera switches to AI Servo AF mode.

Typically, AI Focus mode is used on inexpensive models EOS - This mode is supposed to be used by people with little experience in photography. With AI Focus, we can focus on the scene and let the camera choose for you. best mode filming.

On some models various modes autofocus is set by the camera based on the selected shooting mode - for example, One Shot for landscape mode and AI Servo for sports mode.

All lenses in the EF range support autofocus. However, there are some non-EF lenses in the EOS system that need to be manually focused. These are the Tilt&Shift lenses - TS-E 24mm/45mm/90mm, as well as the MP-E65 f/2.8 1-5x Macro lens.

Autofocus modes

Camera	One Shot AF	AI Servo AF	AI Focus	Manual
EOS 1
EOS 1N
EOS 1N RS		(·)
EOS 1V
EOS 10
EOS 100
EOS 1000/F/N/FN
EOS 3
EOS 30/33
EOS 300
EOS 300V
EOS 3000
EOS 3000N
EOS 5
EOS 50/50E
EOS 500
EOS 500N
EOS 5000
EOS 600
EOS 620
EOS 650
EOS 700
EOS 750
EOS 850
EOSRT		(·)
EOS IX
EOS IX 7
EOS 1D
EOS 1Ds
EOS 10D
EOS D2000
EOS D30
EOS D60
EOS DCS3

This table shows the autofocus modes of EOS cameras. The mode can be set by yourself [·], or the camera itself sets the autofocus mode depending on the selected shooting mode [o]. All cameras except the EOS 650 and 620 have a predictive focusing system with AI Servo AF.

(·) - AI Servo AF mode is not available when the EOS 1N RS is set to RS mode (similarly when EOS RT is set to RT mode).

Selecting the AF Mode

It's always good to know what the camera does - in this table you will find all the necessary information.

Selecting the AF mode is possible only in the Creative Zone (P, Tv, Av, M, DEP), and only on some cameras. In other shooting modes, the camera itself makes a choice:

Camera	Machine	Portrait	Landscape	Macro	Sport	Night
EOS 1
EOS 1N
EOS 1V
EOS 10
EOS 100
EOS 1000/F/N/FN
EOS 3
EOS 30/33
EOS 300
EOS 300V
EOS 3000
EOS 3000N
EOS 5
EOS 50/50E
EOS 500
EOS 500N
EOS 5000
EOS 600
EOS 620/650
EOS 700
EOS 750/850
EOSRT
EOS IX
EOS IX 7
EOS 1D
EOS 1Ds
EOS 10D
EOS D2000
EOS D30
EOS D60
EOS DCS3

U - the user chooses the mode himself
OS - One Shot AF Mode
AF - AI Focus AF Mode
AS - AI Servo AF Mode

Manual focus

And finally, there is a manual focus mode. It can be used with any EOS camera, but the function is not a camera, but a lens. Look at the side of the lens, next to the red dot - you will see a switch with two positions - "AF" and "M". Switch it to the "M" position and the lens will no longer focus automatically. Instead, it will focus according to how you turn the focus ring on the lens itself. The only non-manual EF lens, the EF 35-80mm f/4-5.6 PZ, was a Power Zoom lens sold with the EOS 700.

All EF lenses have been designed with auto focus in mind. If you have used older FD lenses, the manual focusing of EF lenses may not seem as smooth to you as on fully manual FD lenses. Also, from infinity to the closest distance, the focusing ring scrolls rather quickly, making precise focusing difficult in some cases. Be that as it may, it depends on the particular lens.

In general - why do you need manual focus on autofocus lenses? There are some situations where the autofocus system will find it quite difficult to cope: scenes with low contrast - for example, landscapes in fog or the expanse of the sea; scenes with low illumination (in fact, this is a special case of a scene with low contrast); extremely bright reflections from water, ice or metal; objects that move too fast to be automatically focused; scenes in which the main subject is not closest to the camera (for example, an animal in a cage behind bars).

If the main subject is close to the camera, the focus assist system built into the camera (or the more powerful one in the Speedlite) can help, but it only works if the subject is not very far away.

In all such situations, the best way out is to manually focus the lens.

Many USM lenses allow you to manually focus immediately after autofocusing - without the need to constantly switch between manual and auto focus modes. This feature is called Full-Time Manual Focusing (FTMF). This is particularly useful when using telephoto lenses to make final adjustments to focus just before shooting. You can check if your lens has this feature by turning the ring right after autofocusing ends.

How to choose autofocus mode?

The AF mode is only selectable in the Creative Zone (P,Tv,Av,DEP,M). In fully automatic mode (green square) and PIC modes, the camera itself sets the autofocus mode (see table). You just have to make sure that the lens is properly mounted on the camera and is in autofocus ("AF") mode.

EOS 1, 600, 620 and 650 cameras display "M.Focus" when the lens is switched to manual focus mode; on other models, switching to manual mode is not displayed.

After autofocusing, you can lock the focusing distance by setting the lens to "M" mode. This will allow you to remove your finger from the shutter button, compose, and take the picture at the original focus distance.

EOS 1, 1N, 1V, 1D, 1Ds, D2000, DCS 3
Press the AF button on the top left of the camera and turn the parameter dial at the same time until "One Shot" or "AI Servo" is displayed in the upper right corner of the LCD.

EOS 10
Press the yellow AF button on the back of the camera and turn the parameter dial at the same time until "One Shot" or "AI Servo" is displayed in the upper right corner of the LCD.

EOS D30, D60
Press the AF button on the top right of the camera and turn the parameter dial at the same time until "One Shot" or "AI Servo" is displayed in the upper right corner of the LCD.

EOS 10D
Press the AF button on the top right of the camera and turn the parameter dial at the same time until "One Shot" or "AI Servo" is displayed in the lower right corner of the LCD.

EOS 1000/F, 1000/FN, 300, 300V, 3000, 3000N, 500N, 5000, 700, 750, 850, IX7
The autofocus mode is set automatically by the camera depending on the shooting mode.

EOS 30, 33, 50, 50E
Switch the AF mode dial to "One Shot", "AI Focus", or "AI Servo".

EOS 5
Press the AF mode select button on the back of the camera. Turn the parameter dial until the LCD displays "One Shot", "AI Focus" or "AI Servo". If you release the AF mode select button, the selected mode will be active for 6 seconds.

EOS 600, 620, 650, RT, IX
Press the AF mode select button located under the flap on the back of the camera. Turn the dial until the LCD displays "One Shot", "AI Focus", or "AI Servo" (on the EOS 620 and 650 it's just "Servo").

Photos - David Hay, Paul Exton

source eos.nmi.ru 2002-2006 Alexander Zhavoronkov

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. It doesn't matter if we're shooting with an entry-level camera or a professional camera, in order to get sharp pictures, we need to try to figure out how to use the different autofocus modes. Incorrect focusing, a blurred 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 the work of our camera’s focusing system. 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 photography tutorial, we'll cover the basics of autofocus modes on DSLRs. 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 much more friendly to the amateur photographer in this aspect, because, unlike film, we immediately see the result and can easily change the 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 conditions, in 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 how far 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 normal functioning. When the lens starts to “scrawl” over a uniform surface (such as a white wall or some kind of smooth tonal surface), 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 and 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 cameras by building different autofocus systems into them. Entry-level DSLRs typically have a minimum number of focus points to allow for focus, while advanced DSLRs feature 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 various models cameras. Here is an example of two different types autofocus with a different number of focus points and their location.

As you can see, the Nikon D5100 DSLR has 11 points, while the Nikon D810 has 51 of them - a 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 specific area of the image, but also because the AF system can more effectively track the subject in the frame (extraordinarily handy when shooting sports and wildlife). 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 various types auto focus points in DSLRs. As stated above, the number of points is not the only important parameter of an autofocus system. 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 have importance. 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 have chosen (for example, f/22), the aperture changes only at the time 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 digital SLR cameras, 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

These days, most digital SLR cameras has the ability to shoot in various modes of ignorance of focus, depending on the specific 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 the 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 essential when photographing sports, wildlife, and other non-stationary subjects. 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 focusing, AF-C continuous focusing is typically highly customizable (especially on the most expensive DSLRs) and can perform complex tasks such as tracking subjects to 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 For a while, they have AF-C continuous focus tracking enabled, and only when the camera cannot focus in low light conditions do 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 this happens differently for different models. 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 regimes. 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 tracking focus 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” that 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 follow small area in the frame, select 9 points, and if you need to track movement across the entire field of the frame, assign 51 points.

AT recent times 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 the 3D tracking mode is that the camera uses a built-in image recognition system, automatically reading colors and following the subject on its own, and you simply compose the picture while the subject is moving.

For example, we photograph a white heron pacing among 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. Regarding 3D tracking, there are different opinions because it is not as fast as with, for example, 9 dynamic AF points.

3.3 Auto focus area selection mode

For Nikon cameras, it is designated as " Automatic selection AF Area, Canon has “Automatic AF Point Selection” and is a point-and-shoot method of focusing. The camera automatically chooses what to focus on. This is a complex system that can recognize the color of a person's skin in the frame and automatically focus 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 with Canon cameras, but they have this mode called “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

Nikon's latest DSLRs, such as the Nikon D810 and Nikon D4S, have new mode focus area selection “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: the bird sits 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 are 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 are better off using 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 line of 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
AF area selection mode
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 on the table of explanations of the focus area selection modes above: in various models Some options may be missing.

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 learned a lot of 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 (well, or whatever button we 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 does not work correctly, it often makes mistakes, then you can switch to "Dynamic AF" with a fairly 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:

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

Modeautofocus: AF-S, AF-C or AF-A
AF metering area: single point
User settings => Priority selection for AF-S: focus priority
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.

Autofocus mode: AF-S
Measurement: Single point AF
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).

Autofocus mode: AF-C
AF area metering: Dynamic or Group AF
Custom Settings => Dynamic AF: 9 or 21 points
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, you need to be more attentive to what our camera is focused on and remember that special meaning accepts the need for a clear understanding of depth of field (DOF) and hyperfocal distance.

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.

Autofocus mode: AF-S
AF area selection method: Single point AF
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 continuous AF-C tracking mode and the AF area metering method "Dynamic AF" or "3D tracking", both of which work perfectly. Animals are usually not as nimble as birds (although sometimes they can move even faster), so if we're not shooting fast action, it's better to use Dynamic AF with more focus points or apply 3D tracking.

Auto focus mode: AF-C
AF area selection: dynamic focus or 3D tracking
Custom Settings => Dynamic AF: maximum number of points or 3D
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.

Modesautofocus: AF-S, AF-C or AF-A
Measuring method: Single point AF
User settings => Priority selection for AF-S: focus priority
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 "release priority" the camera doesn't care about good focus or bad (why autofocus then?), and in "focus priority" it won't let you take a good picture 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 the general lighting in the hall - all the problems were solved by themselves, and he was able to take great 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 to focus 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 - a 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.

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

Back and front focus

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

Contrast autofocus

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 the case of a kit lens, you will most likely have to deal with apertures 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.

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

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 an AF fine-tuning value that will be applied when no separate setting 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 currently applied 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. Find optimal value can be done with 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.

autofocus. However, accurate and fast focusing is unthinkable without the ability of the photographer to work with points and focus areas. Often you have to shoot children or animals that “run away” from focus every now and then. And sometimes very precise focusing is required: for example, in front of the model's eyes when shooting a portrait.

How to make the camera focus in the right place?

How to work with focus points in different shooting situations? How to make the camera take into sharpness what you need? Let's figure it out.

It is important for the photographer to remember that the camera is a mechanism, although very perfect, but not endowed with reason. The automation of the device can recognize the type of scene being shot thanks to the metering sensor and work with focus accordingly. However, the camera cannot be aware of all the creative ideas of the photographer - he does not know exactly what exactly in the frame you want to focus on.

How to make the device focus in the right place? The camera needs to point to the point that should be in focus. This can be done by selecting zones and focus points. Focus point selection is available with both single-shot AF-S and continuous AF-C.

How to select the desired AF area mode?

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.

Consider options for working with focus points. Each of them is beneficial in certain shooting situations.

Single point autofocus

Focusing occurs on a single focus point, which is selected by the photographer himself using the multi selector. Single-point AF (auto focus) mode gives it full control over focusing. This mode is especially useful for static scenes. These include landscapes, still lifes and portraits, if a person stands still, poses for us.

Single-point focus mode is usually used by default by advanced and professional photographers. It gives excellent results when working with fast portrait optics: when we shoot with it at wide apertures, the depth of field will be extremely small. Consequently, the slightest error with focus threatens that the frames will simply be blurry.

If you need precise focusing with fast optics, then it is easiest to achieve it when working in single-point AF mode.

But this mode also has its downsides. If there is fast movement in the frame (playing children, animals, athletes), we may not have time to select the desired focus point, and the subject will simply “run away” from focus. This is true even when shooting with AF-C continuous autofocus, because when you track the subject, it can easily go beyond the selected focus point, and sharpness will be lost. In such cases, the following AF area modes are useful.

Dynamic AF

This mode is available only with focus tracking (AF-C). In it, we select the main focus point in the same way as with single-point AF. But when focusing, the camera also takes into account information from other, neighboring focus points. Thus, if the subject has moved away from your main focus point, the camera will still follow it, based on data from other sensors.

All modern Nikon SLRs, except for the simplest Nikon D3300, allow you to choose how many focus points will be used to track the object - sensors on the entire frame area or located next to the point chosen by the photographer. The fewer points involved, the more accurate the focus will be, but the easier it is to lose the subject from sharpness. And vice versa: the more sensors are involved, the more difficult it will be to lose the object from sharpness, but the greater the errors can occur when focusing.

Dynamic AF is great for shooting fast-moving subjects. For example, birds in flight.

When working with dynamic AF, do not forget that the main focus point will still be the one you have chosen. So for the most accurate focusing, you need to try to keep it on the subject being shot, not letting it go far from it.

3D tracking

This method, unlike the previous one, allows you to move the active focus point right after our hero automatically.

With AF-C tracking, the photographer selects the desired AF point. After that, if the subject moves, the camera uses the 3D tracking method, moving the focus point after it. Thus, you will not lose sharpness even on a very fast moving object. The most important thing is that the object does not leave the frame. Otherwise, it will have to focus again.

With 3D tracking, the camera registers the colors at the original focus point and then follows them as they move through the frame. Therefore, 3D tracking is most effective when the object being filmed differs in color from the background. Otherwise, 3D tracking may not give the desired results, and the focus will "jump" to objects that are similar in color. Then you should use the dynamic or group AF mode.

Group AF

In advanced models of Nikon cameras (starting with the Nikon D750), it is possible to select not one point for focusing, but a group of simultaneously active points at once. Single-point AF allows you to accurately focus on sharpness, but sometimes speed is more important than accuracy. Focusing on a group of points is well suited for reportage shooting, filming motion. It will also come in handy where the 3D tracking method fails (when the object and background are approximately the same color, when working in a dimly lit room).

Shooting dynamic scenes in low light conditions is a real challenge for the photographer. Group AF is well suited for such conditions.

Auto-area AF

By turning on this mode, you will let the camera's automation decide on its own where in the frame you need to focus. But keep in mind: automation does not know what exactly you want to focus on. Her opinion may not be the same as yours. Usually, the automaton prefers to focus on the objects closest to the camera. Not the fact that those will be your heroes. For the correct operation of the automatic AF area, it is important that the subject being shot stand out in contrast, brightness relative to the background. It is desirable to place the object closer to the center of the frame. Also, do not block the subject with some kind of foreground (for example, shoot a portrait through the branches of a flowering tree) - in this case, the focus will continually “run away” to the foreground.

Focus Area Modes Available in Live View

We know that a completely different type of focus works in Live View - contrast. Therefore, in this mode, you will not find the usual modes of operation with focus points. There are a number of interesting modes of their own, sometimes opening up new opportunities for the photographer.

One of the advantages of contrast focusing in Live View is that we can focus on any area of the frame, even on the very edge. To do this, just move the focus area to the right place in the frame using the multi selector, and in cameras with a touch screen (for example, Nikon D5500) - with a simple touch. AT Nikon cameras we can set a specific size for the focus area.

Normal area AF It is a small rectangle on which focusing occurs. Since the area of the rectangle is small, the focus will be very precise. This mode, like the single-point AF mode when working through the viewfinder, is great for shooting static scenes.

Nikon D810 / Nikon AF-S 50mm f/1.4G Nikkor
When photographing with a shallow depth of field, focus accuracy must be perfect. The Normal Area AF mode will be an excellent choice for such shooting.

Wide area AF suitable for faster, but coarser focusing: focusing occurs on the area that is larger. Mode wide area AF can be used where focusing speed is a priority - when shooting a report, recording a video.

The wide AF mode is appropriate when shooting frames with a large depth of field, when working at closed aperture values. In such situations, perfect focusing accuracy is not required - a large depth of field eliminates focusing flaws.

Frame with a large depth of field. AT this case focusing over a wide AF area is quite possible.

Face priority AF- A function available only with contrast focusing. She will become ideal solution when taking pictures of people. Automation itself recognizes the face in the frame and will continue to follow him, even if the hero moves. This function is well suited for shooting a reportage, for working with universal zoom lenses. But if you shoot with fast portrait lenses, for perfectly accurate focusing, I advise you to use the normal AF area mode. Combined with the AF-F continuous focus mode, face-priority AF is also suitable for dynamic scenes with people (for example, sports), because the camera itself will keep the person's face in focus.

If there are multiple faces in the frame, the unit will focus on the closest face by default. Use the multi selector to select another face to focus on.

Difficulties can begin if a person periodically turns away from the camera or you generally shoot him from the back. This often happens when shooting reportage, shooting sports events. If the camera does not find faces in the frame, focusing will occur in the same way as in the wide area AF mode - along a large rectangle.

Object maintenance is another interesting feature available in Live View mode. In many ways, it resembles the 3D tracking mode. In subject tracking mode, you first need to align the focus area with the subject and press the center of the multi selector. Now the camera will follow the movement of the object in the frame.

It is interesting that object tracking can be carried out both in the mode single-frame autofocus AF-S, and in AF-F continuous focus mode. In AF-S mode, the device will keep the selected object in the focus frame, but it will only focus on your command - by half-pressing the shutter button. In AF-F mode, focus will be constantly maintained. It is perfect for shooting action scenes! It is important to remember only that focusing in Live View mode is more demanding on light than normal. In low light conditions, it is better to use normal focusing through the viewfinder.

Konstantin Voronov

I have been a professional photographer for over 8 years. Field of activity - wedding, portrait, landscape photography. Journalist by education. Developed several courses for the online photography training service Fotoshkola.net. Teacher, master class leader.