Dr. Manas Chakraborty

EFIP, EFIAP

Part – 1

One of the most important aspects of photography is that the picture must be sharp. And to get a sharp image, you need to know which focus modes will work best for your photos. In the October 2021 issue of this newsletter, I discussed the focus in details. Interested readers can go through the article once more to understand better the current discussion. It is very fact that when compared between manual and autofocus, manual focus almost always gives the best results but manual focusing is a big challenge for the photographer in the field of fast-moving subjects like sports photography, birding, wildlife, etc.  It should also be noted that a perfect manual focus for every click is not a child’s play. To reduce the hassle of accurate manual focusing, modern technology has introduced an almost accurate autofocusing system.

Image 1


Image 2

Most modern digital cameras, whether DSLRs or Mirrorless, are now available with advanced autofocus systems, whose (Image 1) complexity is difficult for many photographers to understand and, to be very honest, does not even need that. Whether you’re shooting with an entry-level or professional camera, knowing how to use your camera’s autofocus system effectively is essential to getting a sharply focused picture. A blurry or soft focused image which is not in proper focus, can make even a highly impactful image totally digital junk because it is virtually impossible to correct an image of out-of-focus or soft focus in post-processing. However, lately, some post-processing software with AI is making such images much better still it’s always preferable to avoid such scenarios. Many people do not have a complete idea about the auto focus modes in the camera. But let’s not forget that one of the best ways to improve your photography to a next level is to understand the autofocus modes and the possibilities of their practical application!  (Image 1 and 2)

In simple terms, you can focus on the subject of your picture by manually focusing or autofocusing. In manual focus you will get complete control over the focus, while in autofocus the camera will do this for you.  Before the digital era, when film cameras did not have autofocusing technology, for decades, focusing manually was the only option for photographers. In manual focus mode (MF), you manually adjust the focus ring of the lens to set the focus distance of your lens. The focus of the camera is then completely under your control. Where the subject of your picture is completely fixed, for example, in shooting of an indoor portrait, manual focus can give you the best results. Also, manual focus mode is generally more reliable than autofocus when shooting under low light conditions such as astrophotography and some other scenarios like macros, architectures, and landscapes.

The cameras of the digital age are available to you with both manual as well as sophisticated autofocus system. However, in the age of film cameras, one had to be master in manual focussing to keep the subject of the film in focus. But today, anyone can just switch to the right autofocus mode and get relaxed as the whole job of focussing will be done by your   camera. Trust me, if you use the camera’s autofocus system in the proper way, rest assured that your subject of the frame will not be off-focused. The autofocus system is getting better day by day – even an entry level camera is now enriched with the complex algorithm-rich autofocus systems that can automatically scan the picture scene and easily detect the subject. Some modern cameras can detect the subject’s face and eyes in the picture, whether it is of human or other animal. Using artificial intelligence and machine learning to determine the light and making sharp focus of subject is now the trump card of almost every camera maker. ( Image 3 )

Image 3

Keeping all these complex issues aside, we can concentrate on the issue of sharp focus in our photography. We need nothing but to know about some of the basic features of the camera and it autofocus. Simply depending on the direction of the light, whether it’s incident or reflected ray, the autofocus is of two main types, active and passive. A very common experience when taking pictures is to see green or red light from the camera, especially while shooting in low light. Why do these rays come out of the camera?  The reason is that the camera is trying to actively autofocus with that light ray and measuring the distance of the subject to determine the focal distance of the lens. On the other hand, Passive autofocus is a much more complex approach which primarily depends on the reflected light from the subject. For now, let’s avoid that complexity and move on to taking pictures.

There are basically three types of autofocus systems: –

Contrast detection, Phase detection and a mix of the two – Hybrid.

There’s no problem if we don’t want to dive deeper into the complexity of all these processes. Since the contrast detection autofocus, system requires the light to fall directly into the imaging sensor, the DLSR or Mirrorless camera must be placed in “live view” mode for the contrast detection system to work. In general, this means that DSLRs can use both phase and contrast detection AF, phase detection requires the use of optical viewfinders, but contrast detection autofocus will not do its job unless the LCD on the back of the camera is used.

 Since phase detection AF is much faster than contrast-detection AF, camera makers are using phase detection AF by dedicated phase detection AF sensors directly into imaging sensors. Similarly, most Mirrorless cameras today can do both types of autofocus.

One point we must remember is that the contrast in the scenes to be photographed is one of the main criteria for successful autofocusing.  And the correct application of the autofocus area mode makes a substantial difference in the output of the image.

Image 4

Before we get into the practical application of autofocus area mode when taking pictures, we need to know that we can primarily divide autofocus mode into three types: – AF-S (autofocus- single area autofocus), AF-C (autofocus – continuous) or AI servo; AF-A (Autofocus – Auto) or AF-AI. A very simple tip is to use AF-S when you’re shooting a stationary subject or landscape or portrait where your photographic subject isn’t moving. Conversely, when your subject is moving or you are anticipating the subject’s possible movement (suppose a bird is now sitting on a tree but can fly at any moment), use AF-C mode. Some cameras also have a mode called “AF Auto” (AF-A) or “AI Focus AF” (Canon), which is essentially a hybrid mode that automatically switches between AF-S and AF-C modes. If the camera thinks the subject is stable, the camera switches to AF-S and automatically switches to AF-C mode if the subject moves. By-default, most entry-level cameras are set to AF-A mode, which gives pretty good results in most situations. Many high-end or professional cameras do not have this mode because this fully camera-based mode is mainly designed with the needs of new photographers in mind. Frankly, this mode of autofocusing may not always give you the best results because in this mode you’re only relying on the decisions made by the camera’s AI. ( Image 4 )

Full-time servo (AF-F) focus mode

This particular mode is also known as “AF-F”. Nikon introduced this mode specifically for video recording on its DSLR and Mirrorless cameras. This mode automatically tracks the subject’s movement and focuses on the subject during video recording. If you don’t shoot videos, you may not waste your time with this mode of AF.

Single Type AF Point Image 5


Cross Type AF Point Image 6

From photography perspective, it is more useful to understand the autofocus area mode than the autofocusing method. To take a tack sharp picture in autofocus mode, we need to have some idea of the autofocus point of the frame. Each camera maker typically designs autofocus points in their cameras, and that’s why we see different numbers of autofocus points in different camera make and models. Since autofocus is primarily of two types, contrast detection and phase detection (hybrid type is actually a combination of these two), each autofocus point is also basically of two types, Single and Cross type autofocus points. (Image 5 and 6)

Single type autofocus point can detect contrast in either direction by detecting horizontal or vertical contrast and cross type autofocus point can detect in any direction. That’s why obviously Cross-type autofocus points are more accurate and faster than Single type autofocus points. Another important feature of these Cross-type AF points is the increased sensitivity even in low light. More sensitive in low light means autofocusing is more accurate. AF points of different camera make and models can range from 9 to a few hundred. Naturally, the more AF points there are, the more frame areas will be covered meaning there will be more perfect autofocus.

Sony’s new Alpha 6300 model (Crop Sensor camera) has a 425-phase detection AF point with an autofocus speed of ess than 0.05 seconds. The Nikon Z6 and Z7 are both full-frame Mirrorless cameras with 273 and 493 AF points respectively. Both the type and the number of AF points are very crucial for good autofocusing because Cross type AF points can autofocus more efficiently than Single type AF points.

Autofocus area mode (Image 7)

Image 7

I’ve been talking about autofocus mode so far. Where do this autofocus area mode suddenly come from? One thing to keep in mind here is that the main function of autofocus is to focus automatically. When we see the scene of the picture on the camera’s viewfinder or LCD screen, the camera uses the autofocus area mode to focus the subject of the picture in a more subtle and accurate way through a large number of autofocus points within that frame. In today’s digital cameras, “AF-Area Mode” allows photographers to select a number of options when taking photos in AF-S, AF-C, AF-A, and AF-F modes.  A specific “AF-area mode” can be selected from the menu of entry-level or semi-professional cameras. Pro-level cameras usually have a dedicated button for it. For proper use of AF area mode, read your own camera manual carefully as the menu structure of different camera models is not the same.

What is these AF-area modes? As soon as I get to the answer to this question, I will also discuss the different AF- area modes because there is no way to get the sharp focus of the subject of the picture without this discussion. Generally, AF area mode can be of following types: –

Pin point AF area mode (Image 8)

image 8

It can be said that pinpoint AF mode is a special mode of Nikon camera that uses contrast detection AF to properly focus very small parts of the frame. In fact, this autofocus point focuses on a small spot and you can take it anywhere in the frame if you want and focus only on that small spot. Use this mode if you need specific focus when taking a picture in which the subject is still (e.g. landscape, architecture, product, macro, etc.).  Keep in mind that this is only available in AF-S mode.

 

Single-point AF-area mode (Image 9)

When you take a picture by selecting “Single Point” (Nikon) or “Manual AF Point” (Canon) AF-area mode, the camera will focus on the subject of the frame using only one focus point you select from all the Auto focus points in the frame. So, if you move your focus point up, down, left, or right, the camera will autofocus only by detecting the contrast of that particular focus point.  You can use single point AF-area mode when taking pictures of landscapes, architecture, and other still objects.

Image 9

So, the question arises what is the difference between Spot and Single Point AF Area Mode? In fact, the difference is very subtle. In single point mode, you are selecting any one of the total AF points in your camera frame. Suppose there are 9 and 51 autofocus points in the frame of the two cameras respectively. So, in the case of the first camera, the coverage of the frame per AF point is much higher than the second camera. That is, in both cases, single point AF area mode is used, but the first camera will focus on a lot of area. Now suppose you want to take pictures of multiple small birds in the gap between the leaves of a tree branch, but in the meantime, the bird you want to make the main subject is taking up as much space in the frame as it is less than the single point AF area mode of that camera! That is, if autofocus area is smaller, you can focus only on that single bird, but that is not happening in single point mode. This is where spot AF area mode is needed. Spot mode can focus on smaller spaces than single point mode, and so if you take a picture of your desired bird in that spot mode, the image will reveal a lot more. One thing to keep in mind here is that taking pictures in spot mode with a camera in hand is very difficult because the focus can shift away from the subject at any time.

Dynamic AF Area Mode (Nikon)/Expansion AF Area Mode (Canon) (image 10)

Image 10

In “Dynamic” (Nikon) or “AF Point Expansion” (Canon) AF-area mode, you’re selecting only one focus point, and the camera will primarily focus on that particular focus point. Once focused, if your subject is also moving, the camera will keep the focus on the subject by tracking the subject’s movement to the focus points around. You will try to keep the subject close to the initially selected focus point by panning the camera with the movement of the subject and only then the camera will track your subject. If the camera tracks the subject using other AF points in the vicinity, it may not be seen directly in the viewfinder during capture.

3D Tracking using all AF points Image 11

Dynamic AF-area mode gives great results in the field of birding photography. It is very difficult to keep a fast-moving subject in focus within the frame like a bird when the bird is flying or just going to fly. In high-end DSLRs and Mirrorless cameras, you can select the number of AF points yourself in this dynamic area mode. That is, after deciding your initial focus, you can decide how many focus points you will engage around for the movement of the subject. For example, the Nikon D850 allows the camera to select between 9, 11, 21 and 51 points in dynamic AF-area mode. So, if you want to track only a small part of the frame, you will choose 9 points and if you want to track the entire frame, you can choose all the points i.e., 51 points for the whole frame, including your subject.

Many modern cameras have a “3-D-tracking mode”,(Image 11) where you initially select the AF point and the camera will automatically activate the focus points needed to track the subject’s movement.  The most interesting thing about the 3D-tracking mode is that here the camera uses a special image recognition system through which the camera analyses the colour sequence of the scene in such a way that the camera can automatically track the subject and you can concentrate on composition being free from the thought of focusing on the subject.  Imagine you’re photographing a white bird among many black birds. In this case, if you activate 3-D-tracking mode, the system will automatically focus and track the white bird, even if the bird moves or if you want to recompose your frame by moving the camera.

Dynamic Group Area (D9) Image 12

Here, too, a question arises again. What is the difference between Dynamic AF Area Mode and 3D Tracking? Which one should I use in any case?

Dynamic AF Area (D9) Image 13

Simply put, during 3D tracking, all the autofocus points in the camera use autofocus points to autofocus and track, but in dynamic AF area mode, as many AF points as you have selected for this task will be used by the camera to focus and track the subject. For example, if you select 9 focus points, subject tracking will only be done with 9 focus points and that too will work within a zone that is around your selected focus point. (Image 12) If your subject moves away from these 9 focus points, then the camera will no longer be able to keep the focus on the subject.   In 3D-tracking mode, however, the camera will continue to track the subject (you can see the new selected focus points in the viewfinder), even if the subject’s movements significantly deviate from its initial focus point.

When photographing wildlife, many photographers usually activate a zone-based AF point (9 or 15 AF points) and use the dynamic AF-area mode a lot and in most cases, they get very good results. However, if the picture is very chaotic and suppose a bunch of birds are flying towards me (i.e., towards the camera), then choosing the 3D-tracking mode will be the best bet to focus the subject and continuously track. ( Image 13)

Auto-area AF mode

Auto Area AF Image 14

“Auto-Area AF” (Nikon) or “Auto AF Point Selection” (Canon) mode is the “point-and-shoot” method of focus. Depending on what picture you’re taking, it will automatically select what to focus on. It’s a pretty complicated mode because it will actually recognize a person’s skin tone in the frame and automatically focus on them. If there are more than one person in the frame, this mode will focus on the person closest to the camera. If the camera can’t recognize a skin tone, it will usually focus on the thing closest or largest size in the frame. If you shoot in AF-S mode and select “Auto-Area AF”, the camera will show which focus points to use for a second so you can understand which zone the camera is focusing on. The same can be done on a Canon camera, but then call it “one-shot AF mode (auto AF point selection)”. (Image 14)

Group-area AF mode (Image 15)

Group Area AF Area Mode Image 15

This Nikon-specific mode is called “Group-Area Autofocus.”   Compared with Single-Point AF mode, group-area AF mode activates five focus points to track the subject. This focus mode is great for primary focus and tracking of the subject compared to single-point or dynamic AF, especially in photographing small birds because these small birds often fly irregularly and often, they offer really difficult challenge to track and focus. In this situation, group-area AF mode can give better results than dynamic AF.

How does Group-Area AF work?  Basically, in the viewfinder, you’ll see four focus points, the fifth hidden in the middle. You can move up to four focus points by pressing the multi-controller behind the camera (to get the best result, you may want to focus in the middle of the frame, because the focus points in the centre of the frame are cross-type and autofocus is the most perfect here). When the camera is pointing at a subject, the five focus points for the primary focus are activated simultaneously but give priority to the subject closest to the camera.  This is slightly different from the dynamic 9 (D9) AF mode, because of the 9 focus points selected in D9 mode, the centre focus point activates the other 8 focus points around the centre focus point by prioritizing it.  In D-9 mode, if the camera fails to focus using the centre focus point (let’s say there is not enough contrast in that area of the frame), then it tries to focus with the remaining 8 focus points. In this mode, the camera will basically prioritize the centre focus point and only then will the other 8 focus points be exploited if autofocus is not possible. But the group-area AF will simultaneously use all 5 focus points and try to focus on the nearest subject without giving priority to any of the 5 focus points.

Group-area AF is a particularly useful mode when photographing birds, wildlife, and non-team sports. An example can be given. Suppose there is a bird sitting on a tree branch and you are looking at the bird from a little above and for that angle there is clear ground behind the bird. In dynamic AF mode, the camera will try to focus primarily on the bird. If you can point the camera at the bird in the right way, the camera will focus on the bird. But if you accidentally point the camera at the ground behind the bird, the camera will leave the bird and focus on the background. This mode can be quite challenging when photographing small birds, especially if the tree branches, they sit on are constantly moving. The sooner you secure the primary focus point, the better the chances of capturing and tracking the picture, especially if the bird suddenly flies.

Eye Detection AF Image 16

In group-area AF-mode, no focus points are prioritized, so all five focus points are active together. In this particular situation, since the bird is closer than the background, only if one of the 5 focus points is close to the bird, then the camera will focus on the bird, not the background. Once the focus is secure, the group-area will also track the subject in AF mode (if any of the 5 focus points are close to the subject). If the subject of the frame moves quickly and you cannot pan your camera in accordance to the direction of the movement of the subject, then the focus will be lost.  The same will happen in dynamic 9AF mode. When it comes to tracking, group-area AF is pretty fast but it’s hard to tell if it’s as fast as dynamic 9AF – in some situations, dynamic 9AF seems to do some fast tracking. (Image 16)

When you use group area AF in AF-S mode, the camera will then   try to focus on the face (face detection) or eye (eye detection). Suppose you take a picture of a person through the branches and leaves of a tree; the camera will try to focus on the person’s face or eyes instead of the leaves of the tree. Keep in mind that this face or eye detection is only active in AF-S mode (Nikon camera). So, if you do fast action sports photography with a Nikon camera and want to lock the focus on the face of a particular subject (here the player) and track him only, then you have to use dynamic AF-area mode.

Other area modes

Some new Nikon cameras have additional AF-area modes such as “Face-Priority AF”, “Wide-Area AF”, “Normal-Area AF” and “Subject-Tracking AF” for use in video recording. I’m not going into detail about each of these, as they are specific to specific camera models and will likely to change in the future. The Canon camera also has some AF-area modes like “Spot AF”, where you can make your focus more subtle within the focus point.

Similarly different AF area modes are also available in AF-C autofocus mode, and all these AF area modes can give you the desired results together with the appropriate autofocus mode. For the purpose of photographing, if one does not want to go deeper into the complexity of AF area mode and AF mode, then read the simple and simple formulation below (A-F mode and A-F Area Mode are not the same thing at all!)

 

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Auto-Focus and Auto-Focus Area-Mode

Dr. Manas Chakraborty

EFIP, EFIAP

Part – 2

 

Auto-focus and its examples in different situations

So far, you’ve got plenty of technical information on each focus mode and AF-Area mode. But at the end of the day, we’ll take pictures. So, let’s discuss various real-world scenarios and examples to understand the above discussion from the perspective of photography. Since I use Nikon cameras myself, I mentioned Nikon’s settings in the discussion. But these settings will also be available in other brands of cameras, maybe there will be some variation in the nomenclature.

Outdoor Sports photos  (Image 17)

Image 17,3D tracking, PC Sayantan Chakraborty

Which autofocus mode and AF-area mode would you select when photographing outdoor sports like football? Let’s start by selecting the right autofocus mode first. Obviously, using a single AF/AF-S mode won’t work, as your camera’s shutter will need to constantly refocus as you press the shutter half-press or back button, or press a specific AF-on button. So, we must use AF-C or AF-A modes. In this situation, we know that our subject (here the football players) is always in the movement in the field, so we will only choose the AF-C mode. What will be the A-F area mode?

In AF-Area mode, the best option is 3-D tracking. In this mode, your camera will continue to focus and track the player you’re interested in, and you’ll just compose the shot. Usually this 3-D tracking gives very good results, but if it can’t track your subject properly (or you may want to track and focus on a particular player), switch to Dynamic AF-area mode with a relatively high number of focus points, especially if you’re too close to the field’s side line. Group-Area AF will work great if you just want to track the player closest to the camera.  Here’s a summary of the settings that will yield the best results:

1.Autofocus mode: AF-C

2.AF-Area mode: 3D-Tracking, Dynamic AF-area or Group-Area AF

3.Custom          Settings->Dynamic AF Region: 21-point or 51-point

4.Custom          Settings->AF-C Priority Selection: Release + Focus

 

Pictures of people in the outdoors (Image 18)

Outdoor People Image 18

When taking an outdoor portrait that poses for you in daylight, any autofocus mode gives very good results.  If you shoot in AF-S mode, the camera will only focus once when you press the shutter in half, so make sure that you or your subject does not move after securing the focus just before taking the picture. According to the default settings of AF-S mode, your camera will not let you release the shutter until the focus on the subject is properly secured. If you’re shooting in AF-C mode, make sure to secure the focus well before taking a picture. AF-A mode can also give great results for portraits. When it comes to AF-area mode, select Single-Point AF-area mode because your subject is static in this case. Then the camera’s full autofocus settings will be –

1.Autofocus mode: AF-S (Preferable), AF-C or AF-A

  1. 2. AF-Area Mode: Single-Point AF-Area (Preferable) or any other AF-Area mode

3.Custom Settings->AF-S Priority Selection: Focus

4.Custom Settings->AF-C Priority Selection: Release + Focus

 

Outdoor Portrait Imag

We all know that during portrait shooting, the subject’s eyes, especially the eye that is closer to the camera, are of the best interest to focus. If you’re using a modern DSLR or Mirrorless camera with Face or Eye-detection autofocus modes, be sure to use them! The settings for the Nikon Z mirrorless camera will be as follows: (Image 19)

1.Autofocus mode: AF-S, AF-C

  1. 2. AF-Area Mode: Auto-Area AF

3.Custom Settings->Auto-Area AF Face/Eye Detection: Face and Eye Detection

4.Custom Settings->AF-S Priority Selection: Focus; AF-C Priority Selection Release + Focus

Indoor portrait shoot (Image 20)

Indoor Portrait Image 20

Indoor portrait shoots in low light can sometimes be quite challenging.  If you want to take pictures in low light, use AF-S mode so that the AF-Assist beam can help you if needed. If you use a speedlight, AF-S mode will use AF-assist beams (red or green) to focus, but you will not get the benefit of this assist beam in AF-C mode. Although the AF-A mode works well in such situations, it would be wise to use the AF-S mode. In the case of AF-area mode, choose single-point AF-area mode and select centre autofocus point for better focus when shooting in low light conditions. So, in short, the camera settings stand: –

1.Autofocus mode: AF-S

  1. 2. AF-Area Mode: Single-Point AF-Area

3.Custom Settings->AF-S Priority Selection: Focus

4.Custom Settings->Lo-Light AF: On

 

Bird Photography Image 21, PC- Asok Samaddar

Picture of birds flying in the sky (Image 21)

Photographing birds is always difficult because it is virtually impossible to predict their behaviour and birds often move very quickly. Therefore, to keep the bird in proper focus, the continuous AF/AF-C mode and the Group-Area AF mode or Dynamic AF-area mode with focus points between 9 and 21 will be the trump card.  (You can also put focus points at 21, but 9 usually focuses faster). One thing to keep in mind is that autofocus can be slower and less reliable than using 51 focus points to photograph birds and shooting in 3D-tracking mode. Most photographers use centre focus points in 99% of the time when photographing birds, and only change focus points when birds are sitting on a tree branch or something. With a centre focus point, Group-Area-AF won’t disappoint you in terms of focus.

Let’s once again summarize the above discussion and look at the camera settings:

1.Autofocus mode: AF-C

2.AF-Area Mode: Dynamic AF-Area, Group-Area AF or 3D-Tracking

3.Custom Settings->Dynamic AF Area: 9 or 21-point

4.Custom Settings->AF-C Priority Selection: Release + Focus

 

Images of landscape and architecture (Image 22)

Landscape and Architecture, Image 22

For landscape and architecture, any autofocus mode and autofocus area focus mode give good results, but many photographers prefer to take pictures in AF-S and Pin-Point mode because there is nothing in the frame to track in this case. In low-light conditions, you can’t use the AF-Assist function on your camera in any way (due to distance issues). Use Live View, if possible, for proper focus (zoom in 100% first) and focus on a bright object in the frame. Another viable option for low-light landscape photography is to turn off autofocus and focus solely manually. When photographing landscapes and architecture, you have to be extremely careful about where to focus, including the concept of hyperfocal distance.  You can use pinpoint AF or single-point AF-area mode to focus properly on a specific area.

So, let’s see what the autofocus settings of the camera will be: –

1.Autofocus mode: AF-S

2.AF-Area Mode: Pinpoint AF/Single-Point AF-Area Mode

3.Custom Settings->AF-S Priority Selection: Focus

 

Photographing large animals / wildlife (Image 23)

Wildlife, Image 23

When photographing large animals or wild animals, set your camera’s autofocus mode in Continuous-AF/AF-C mode and choose AF area mode as Dynamic AF-Area or 3-D-tracking mode; Rest assured, the results will be good. Animals aren’t usually as fast as birds (although some wild animals will sometimes run so fast to catch prey or not to be hunt that none of the above makes sense), so if you’re not photographing fast action, select dynamic AF-areas with the maximum number of focus points or 3-D. Use tracking. In this context, it is good to say that when you take pictures of wildlife, make an idea about the forest in advance. Find out which types of wild animals are more likely to be photographed there and what their lifestyle is. Are they relatively slowing animals? Or too angry? If it is a relatively slow animal, then it will be done as it is told right now and if it is very fast moving, then use the idea of taking pictures of the bird.

If you look at the above discussion in the camera settings, it will look like this: –

1.Autofocus mode: AF-C

  1. 2. AF-Area Mode: Dynamic AF-Area/3-D-Tracking

3.Custom Settings->Dynamic AF Area: Maximum number of AF points or 3-D tracking

4.Custom Settings->AF-C Priority Selection: Release + Focus

A picture of a group of animals or people from a distance  (Image 24)

Group of People, Image 24

If you’re using a telephoto lens, you’ll need to be careful about camera-to-subject distances when using large apertures. If you stand too close to the group and use a larger aperture such as f /1.4-f/2.8, only one or two will be in focus, while others will be blur by being out of focus (unless everyone is on the same focal plane) by increasing the f number (at least f-8 or higher) if a higher depth of field image is necessary. Or go back/ away from the group and take pictures, so that the depth of field increases or you can use both methods. If you want to blur the background, take pictures in a small F number (i.e., in a large aperture) and put everyone in the same focal plane parallel to your camera. If you’re shooting in daylight, any AF mode can focus well, but choosing a Single-Point AF-area mode to focus on a particular subject will allow you to be much more relaxed.

In this case, the camera settings will be: –

1.Autofocus mode: AF-S, AF-C or AF-A

  1. 2. AF-Area Mode: Single-Point AF-Area or AF-Area Auto with Face/ Eye detection

3.Custom Settings->AF-S Priority Selection: Focus

4.Custom Settings->AF-C Priority Selection: Release + Focus

One thing you must keep in mind is that when you shoot in AF-S mode, keep the camera’s custom setting in focus, which means the shutter won’t be released until the subject is in focus. For this you will get pictures in perfect focus. But when you shoot in AF-C mode, make it focus + release. This means that when you take a picture of the moving subject, your shutter focuses and then clicks. So, what’s the difference from the previous one? The difference is that in AF-C mode you prefer both subject and movement —. Since this AF-C mode also captures the action of a scene, the focus and release will be done consecutively without the condition that the shutter will not be released until it comes to focus (there may be a focus problem in one or two frames).  

Tips to improve autofocus in low light

We have experienced while taking pictures that it is quite easy to focus in strong light, sunny environments, and that is quite well done in our camera. But the problem of autofocus starts in low light environments, especially when shooting indoors or say, Night Photography. If it is difficult to shoot the subject with the right focus in low light, then keep the following things in mind, it will work.

Use centre focus points

Your camera may have 9 or 51 or more focus points, but when you take pictures in low light conditions, use centre focus points instead of using the focus points in the corner of the frame because all camera makers give much more sensitive, cross-type autofocus points in the centre of the frame. These Cross-Type focus points are much lighter sensitive than Single-Type AF points. Inevitably, a question arises that how do we make a spectacular composition by autofocusing on the centre of the frame? When taking pictures, we look for golden points to place the subject. Now if your camera can use Back-Button autofocusing in addition to focusing by half pressing the shutter, then definitely make it your “Focus Habit“. In Back Button focusing, you focus on the cross-type AF point in the centre, and then while pressing the back button focus point behind the camera or elsewhere, you easily recompose the frame.  Most digital / mirrorless cameras, including entry-level, nowadays have a dedicated button called “AF-on” to autofocus or you can easily activate the back button auto focus by going to the camera menu [“Custom Settings” – > “AF- Activation” – > “AF- On Only” (Nikon)]. However, if you take a picture with a shallow depth of field, then you have to take extra care when recomposing your frame after focusing so that the main subject of your photo does not go out of the focal plane. If so, the main subject may become out of focus.

Use “AF-assist

Use this feature of the camera to give the subject the right focus in low light by using active AF. To activate this feature, check if “AF-Assist” is turned on in your camera’s menu and AF-S mode is selected. If you have a Nikon Z mirrorless camera, make sure the “low-light AF” option is turned on. Be sure to use speedlights in very low light environments.

 

Find contrast and edges

Focus on something that contrasts with the background instead of a simple, smooth edge subject without recognisable spatial or colour contrast with the background and you’ll see that auto focus is much better and faster. 

Add extra light to the image

Doesn’t that sound strange? It’s real, but that’s it.  If your camera has trouble focusing, what could be easier than adding more lights or turning on more lights in the room?

Keep an eye on shutter speed.

Many times, the camera shakes due to low shutter speed, it seems that the subject is not in the right focus while viewing the image. It looks like out of focus or soft focus, but it’s actually a camera shake that makes the image looks like that. When taking pictures with the camera in hand, using a camera with in-body image stabilization or a lens with optical image stabilization will definitely give some relief, but your shutter speed should not be too low. In taking hand held pictures, keep in mind a simple calculation that the shutter speed should not be less than the focal length in mm. Many people can take pictures without shaking the camera even with a very low shutter speed, but it has to be considered as their personal skill.

Use live view contrast detection autofocus

Try focusing on live view mode using contrast detection AF. It is slower than phase detection autofocuses but is certainly more reliable in low light conditions. When using live view mode, tripods and manual focus on personal needs give better results.  It’s also much easier to focus manually in live view mode, since you’re looking at the image frame on a LARGER LCD than an optical viewfinder. In live view mode, you can zoom in 100% while focusing to see if the subject is in the right focus. Most mirrorless cameras automatically switch to contrast detection AF in low light.

Use flashlights

If your camera does not have an in-built AF-assist lamp, then use an external flash or any light, you will see that you can avoid the trouble of low light focus. Ask the fellow photographer to put the light on the subject. Secure the focus in that extra light and switch from autofocus mode to manual focus mode. If the subject does not move, then the camera will retain the previous focus and you will see that there is a beautiful focus even in very low light.

Use manual focus

Although the subject of our discussion is the autofocus, the best bet to focus in low light is Manual Focus. With the help of modern technology, autofocus is a 24-hour companion of taking picture, but in some cases the manual focus is your saviour and there is no reason to be surprised when you see that sometimes the manual focus is working much faster than autofocus in low light situations. Knowing the details of autofocus is undoubtedly rewarding but also keep the practice of manual focus, it will be your saviour.

Taking your photography to another height by focusing sharp, the high-tech astounding quality autofocusing system is provided to your own camera by the camera makers (and you also paid for it). You just grab the concept and few technical aspects of this Autofocus and its different area mode so that you can engage your camera to focus sharp and you can concentrate on Aesthetics, Composition, Expressions, Light, Shadows, etc. and with other various artistic elements. Understand these features of your camera beforehand so that you do not have to pay attention to this technical trick while doing photography. Definitely we love to enter the arena of art of this visual medium but that path is certainly not through bypassing the technical details, rather know your camera better to outpour your best in Photography.