Tracking and single-frame autofocus: when to use which? Upper focus point
In the last lecture, we studied the main parameters of a photographic lens and some of the technologies used. Knowing what focal length and aperture are will help you in any situation to correctly determine the right set of optics. Today we'll take a closer look at the effects different models bring to photography, whether it's shooting very small subjects or visual magnification space, and also learn how the manual and auto focus system works. First, let's take a look at some photos taken with different models NIKKOR lenses. Each of the photographs shown has feature, and it was the lenses that made it possible to achieve such effects, the camera model is absolutely unimportant here. Let's see how you can achieve similar results.
macro lens
Photo from ladybug we got with a macro lens. In fact, this is an ordinary lens, but at the same time special design allows it to focus at very close distances, which is important when shooting small objects. There are two things to keep in mind when using a macro lens. First, to get good shot it is necessary to provide enough light, this can be done with a flash. And secondly, in macro photography, the depth of field is usually very small, so it is better to keep the aperture in the range of values \u200b\u200bfrom 5.6 to 16. More open and closed positions, in addition, can give worse sharpness. Of course, you can use a macro lens for general shooting, but keep in mind that the picture is sharper and more contrast than conventional lenses, which may be undesirable when shooting portraits. As for the choice of a specific model, among NIKKOR lenses, two models are available for cameras with a cropped and full-format matrix. For crop, these are 40 mm / 2.8 and 85 mm / 3.5 lenses. And for cameras D600 and above, these are 60 mm / 2.8 and 105 mm / 2.8, which you can also use on younger cameras, but due to the smaller size of the matrix, their focal length will increase by one and a half times.
fish-eye
Another option for a lens with a special effect can be called models of the Fish-eye category (per. "fisheye"). There are two of them in the NIKKOR line: 105 mm / 2.8 - for crop and 16 mm / 2.8 - for full format. A feature of the fisheye lens is an ultra-wide shooting angle close to 180 degrees, and strong distortion, that is, distortion. Such models are used mainly for creative shooting, and photographing people with them is real fun.
As for conventional wide-angle lenses (Small FR image), they can also be used to achieve interesting results. As I said in the last lecture, wide-angle lenses divide space very clearly and you can easily distinguish between foreground and background. And the effect of distortion, especially noticeable at the edges of the frame, makes it possible to change the proportions of the objects being shot and achieve extraordinary results. Among wide-angle lenses, you can find both zoom lenses and "fixes". Of course, the zoom in this case will be much more convenient, but remember that fast zooms are much more expensive than fast fixes, and the wide-angle range is no exception. Also, owners of the D3000 and D5000 series cameras need to remember that they do not have a built-in focus drive and only manual focusing will be available with AF lenses, and models with the AF-S marking are needed for automatic focusing.
Shallow depth of field
The next example of an artistic application of the lens would be the use of a shallow depth of field when shooting a portrait. As you remember, the easiest way to achieve this effect is to open the aperture wider. This can be done at fast zooms, for example, 24-70 / 2.8 or 70-200 / 2.8, but a clear recommendation would be to use a fast aperture, for example 50 mm or 85 mm. Both models are available in versions with a maximum aperture of 1.8 and 1.4.
But what if you don’t have such a lens yet, or if you took one “zoom” for all occasions on vacation, but you want to get a shallow depth of field? Two conditions must be met: use long focal lengths (minimum 70mm) and make sure that there is a lot of space between the model and the background. In this case, the laws of optics will help you blur the background and get the effect of the airiness of the frame. However, remember that the nature of the blur, which is called "bokeh", is also different for each model, and with fast "fixes" bokeh, according to subjective sensations, looks much better.
perspective
And the last of the examples, we will consider the effect of a telephoto lens on the resulting image. In addition to the usual approximation of distant objects, with the help of the "telephoto" we can influence such a parameter as perspective. For example, we took two pictures with different focal lengths. As you can see, when using a wide angle, the distance between the main object and the background seems to be significant, and in the case of a large focal length, the perspective shrinks and the background visually comes closer. It is worth paying attention to the fact that the change in perspective is not actually affected by a change in focal length, but by the distance from the photographer to the subject. Using a telephoto lens, we had to move further away from the subject, which is why the perspective in the two shots turned out to be different.
Focusing
Two methods of focusing are available to modern photographers: manual and automatic. Switching between them is usually possible on the lens barrel, and in cameras D7000 and above, another switch is available - in the left front of the body. In the case of manual focus, you will need to rotate the ring on the lens and follow the changes in the viewfinder. This method can help when shooting very fast moving objects or in low light conditions, when the automation may not work. But, of course, the automatic focus mode is the main one today. It is activated by a simple half-press of the shooting button, but, despite this simplicity, the machine has additional settings, among which two can be distinguished: the operating mode and the choice of focus points.
Focus modes
Nikon cameras have three autofocus modes: AF-S, AF-C and AF-A. If AF-S mode is selected, then pressing the shutter button halfway will focus the camera and fix the position of the lenses. If you want to refocus, you will need to press the button again. And in AF-C mode, you can hold down the capture button, move the camera, and it will automatically refocus. This method can be useful if the scene you are shooting is constantly changing and you want to select best moment for shooting. As for the AF-A mode, this is an auto-selection between AF-S and AF-C, the camera will decide for itself which autofocus mode to use.
In younger cameras, you can select one of the modes through the general menu in the “Focus Mode” item. On the D7000 and above, press the button on the left front of the case and rotate the rear command dial.
Focus point selection
In parallel with the choice of focus mode, you can decide whether the camera will automatically select the place where you want to focus, or you do it yourself. In younger cameras, one of the ways to control focus points can be selected through the general menu in the "AF area mode" item. And in cameras D7000 and higher - using the AF / M button in the front of the case, but you need to rotate the front dial.
If you have selected the AF-S mode, then two options will be available to you: automatic and spot. And when choosing AF-C, two more become available: dynamic and 3D. Everything is clear with auto-selection of points: you press the capture button, the camera focuses in one of the zones and takes a picture. This solution has advantages, but there is also a big disadvantage - the camera does not know where the photographer himself wants to focus on. In the case of dynamic and 3D selection, it is more convenient to keep moving objects in focus. Dynamic selection helps us not to lose the subject when the photographer himself moves the camera behind the subject and waits for the right moment to shoot. And in 3D mode, the camera itself will change the focus area following the movement of the object. But the simplest and effective installation to start learning, you still have to choose one focus point.
Once you have set the single-point focusing mode through the general menu or using the button on the front of the camera, it is enough to look through the viewfinder and select the area using the joystick on the rear panel. If nothing is displayed in your viewfinder, then most likely the camera has entered standby mode and you need to “wake it up” by simply half-pressing the capture button. Single point mode has the most precise control over focus area selection of any auto mode, and I recommend using it. However, do not forget that for correct operation autofocus needs one indispensable condition - that the focus point falls into the contrast area. If you try to focus on White list paper or any other plain surface, then nothing will come of it. For the same reason, problems with autofocus in the evening are possible: if our eyes still distinguish between contrast transitions, then for the camera the world may already look like a big dark spot.
In this tutorial, we have learned all the necessary settings related to lenses and focus. A few exercises from homework will help you consolidate your knowledge and choose for yourself best parameters work. In the next lecture, we will explore another interesting element photographic system - we will talk about flashes.
Now in our photography course there will be a couple of rather boring, but necessary lessons on the way to professional photography. The first one is about working with focus. More specifically, how to properly set the focus, what are the focus modes, focus areas, and when is it better to use which focus mode.
Involuntary epigraph. I advise you to read this lesson of our photo school with digital, best of all with a mirror, camera in hand and try to apply what is written immediately in practice.
The games are over, and it's time to take the first step into adulthood. Today I will tell you in detail about focus and how to work with it. (I talked about what focus is and its basic properties in our Photography Lesson #3).
So. The camera needs to be shown WHAT to focus on. To do this, he has focus zones.
Focus zones.
The sizes of the focus areas can vary: from a simple point to a fairly large area.
This is what the focus area switch might look like.
With a dot, everything is more or less clear:
1. Choose where the focus will occur (for example, in the center of the frame or along the edges of the zone). In this case, focusing occurs only in the small square that you have selected.
2. Frame the frame. In this case, what you will focus on should be in the zone you have chosen.
3. Actually, take pictures.
In this case, you rigidly indicate where focusing will occur, taking away any initiative from the poor camera. In a camera, this type of focusing is called " single-zone autofocus.
In most cases, the focus area is left in the center. And in those rare moments when the focus object is not in the middle, they do this:
- put the object they want to focus on in the middle.
- press the shutter button halfway (in this position, the camera does not take a picture, but adjusts the focus. The picture will be taken if you press the shutter button all the way). They wait until the camera adjusts the focus, emitting, as a rule, a characteristic squeak (if it didn’t, read the “focus modes” below in the same chapter. You can throw the camera out a little later, if anything).
- keeping the button pressed halfway, in order to keep the focus fixed, build the frame as necessary. For example, so that the subject is in the upper right corner.
- press the shutter button to the end. Get a professional photo.
In the second option, you choose small area, consisting of SEVERAL points. And already move it in the viewfinder. It turns out that the focus is caught not by one point, but by a kind of trap for a point. This method is called "group dynamic autofocus"
The third way for the most courageous - you "give the camera" the entire autofocus area, and he already looks for the CLOSEST object in it and focuses on it. This method has a "simple" name. "autofocus with dynamic focus selection and closest subject priority".
That's all I wanted to tell you about focus areas. But this is not far from the end of the photo lesson. In order to completely confuse you, they also came up with focus modes. Although those villains who invented them sincerely believed that they were doing a good and useful deed.
Focus modes
When I talked about focus areas, I was answering the question "WHERE will focusing occur?". Now I will tell you how it will work.
Let's try to figure it out in order. There are three focus modes: tracking, single-frame and manual (who would have thought, but sometimes you need it too!).
This is what the focus mode switch might look like.
When should you use single-frame focus?
Single frame focusing is, in my personal opinion, the most perfect and easiest kind of focusing. It's usually enabled by default. digital cameras. It works as follows.
First option. You press the shutter button halfway, not all the way. The camera focuses on the subject. Beeps and LOCKS focus. That is, it does not change it anymore. After that, you can (while holding the button halfway down) shift the frame in the direction you need and take a picture.
My friend, who often shoots with his favorite "soap box" in clubs, faced a problem - in many rooms of the club it is too dark, and autofocus does not work there. He solves this problem in the following way. Looks for something in the illuminated area of the club that is about the same distance as the object he wants to shoot. Focuses on a "light object",blocks autofocus, moves the camera to a dark place and already takes a picture.
The second option is even easier. Just select the subject and press the shutter button all the way down. The camera focuses and immediately takes the picture.
As I said, this method of focusing is most often used. It is the most accurate and is suitable for shooting still and slow-moving objects.
When should you use focus tracking?
Focus tracking is useful for shooting moving subjects. In fact, the camera is TRYING ( keyword) to keep a moving subject in focus. That is, the focus motor works constantly and changes the focal length. But how he does it depends on where you shoot, and on what kind of object it is, and how fast it moves. And, of course, from the camera itself. This option can be useful when you're taking multiple photos in a row (or burst shooting).
The AF tracking mode starts working when you press the shutter button halfway. While you press it, the camera tries to keep the subject in focus. When you press the button, it will take a picture. If you let go, it will stop working.
When to use manual focus
How manual focus works is clear - with handles, my dear friend, with handles! Turn the focus ring or wheel, or pull the lever. And here are the cases when it should be used.
1. A small amount of light.
It is clear why. The camera itself does not see what to focus on - it is dark for it. Many cameras have an autofocus light that is designed to help with focusing, but it often fails.
2. Photo in motion.
Usually, in order to shoot moving objects, tracking autofocus is needed. But, if he does not cope and does not keep up with the object, then you can do the following. Use manual focus to set the camera to where the subject is expected to appear. When he appeared in this place, the main thing is to press the shutter button in time.
3. Shooting a portrait or some conceived complex composition.
When only one detail is in focus, it is often easier and more convenient to adjust the focus in manual mode.
4. Shooting through glass or mesh.
Well, everything is clear here. The camera does not know that you need to shoot what is behind the fence, and stubbornly focuses on the reflection in the glass or on the grid. Therefore, it is necessary to forcibly adjust the focus on objects “behind the glass”.
5. Macro photography.
I will not explain what this is within the framework of this photo lesson. In a nutshell - shooting objects from a very close distance. So that in the frame they turn out very large.
The camera does not always willingly and obediently focus on such short distances. Sometimes they don't focus at all. Yes, and with focus areas is not so simple.
6. A photograph of the texture - a flat surface on which there are no contrasting places.
The fact is that autofocus is based on the contrast of colors. If you try to bring something that has a flat white surface to your eyes (for example, a sheet of paper), then you can easily notice that the eyes themselves begin to look for strokes, dashes, villi - whatever. Because the eye cannot focus on a really monophonic material. Likewise for the camera. The greater the contrast, the easier it is to focus (especially in difficult lighting). And if the filmed is something monotonous and inexpressive, also poorly lit, then the camera may simply not focus on it, and you will have to use manual focus.
And finally. Each lens (or a camera with a lens, if they are indivisible “until death us do part”) has a minimum distance that it can focus on. That is, closer - the image in the photo will already be blurry. You can find out this “critical” distance from the passport, from the scale on the lens ...
Or experimentally, having tried to shoot, gradually reducing the distance. By the way, it happens that the “passport” distance differs from the real one.
The maximum focusing distance is usually infinity. And it comes after a certain footage. That is. Up to, for example, one and a half meters, you need to adjust the focus. After one and a half meters - no more. Anything further will be sharp.
I have given you a lot of information about focusing. All of them apply to most SLR cameras. The notation may be different, but the meaning remains the same. Cameras have different controls, the number of focus points, the availability of modes, but the principle remains the same. I would advise you to practice a little in different modes. Over time, you will, without hesitation, choose optimal mode. Well, when you become a professional photographer... Although you need it? Maybe it's better to just be a person who takes beautiful photos?
The most common complaints I hear from most photographers of any level are "my images aren't sharp" and "I can't get focus." Many people blame their equipment and, indeed, there are many cases in which the equipment is to blame. However, I have found that the vast majority of cases are simple user errors. They often boil down to a lack of understanding of how the autofocus (AF) system works. This article will give you a better idea of focus and sharpness, and hopefully help you get photos you're happy with!
1. Adjust your diopters
What are mine, you ask? Your diopters - or your eyepieces. You will never know if a camera is well focused on a subject unless you can see for yourself what is in focus through the viewfinder eyepiece. On the side of the eyepiece (as shown below) there is a small wheel to adjust the focus of the eyepiece to suit your vision.
You can adjust the eyepiece to quite a large correction, but if you need even more correction, then interchangeable diopters are available for DSLR / SLR cameras from many major manufacturers in the range from -5 to +4. No, this won't help your autofocus work better, but it will help you recognize when it misses and correct the situation with manual focus.
2. Understand your viewfinder
What the hell do all these things inside mean? At this point, you might want to get the instructions (remember that paper book that came with your camera?). Most conventional DSLR cameras have 9-11 focus points. The best of the best, professional cameras can have from 45 to 51 points (although in fact you can only choose 11-19, the rest of the points are optional).
There are two types of focus points: co-plane and intersection points. Single plane points only work on contrast lines that are directly perpendicular (90°) to their orientation. So, if you're looking through your viewfinder like the one above, you'll see that most of the dots are rectangular, some are oriented horizontally, some are oriented vertically.
Points of the same plane will only work perpendicular to their orientation. So - let's say you were shooting a tree - a vertical focus point wouldn't be able to find the edge of the tree trunk, but a horizontal one would. You can use this to your advantage when choosing a focus point that will lock onto the line you want and ignore those you don't want to focus on.
Cross point focus points will work with lines of contrast placed in any way. Most cameras have a single focusing intersection point in the center, surrounded by points on the same plane. The newest cameras today contain intersection points at all focal points.
Each focus point also has a specific sensitivity. Most require a lens with limit value aperture of at least f5.6 to at least use autofocus. On most cameras, the surrounding AF points are exactly this sensitivity, and the center point provides hypersensitivity if you are using a lens with an aperture limit of at least f2.8.
So if you are working under low light, you can achieve better autofocus using the center focus point. Even if you don't use an f2.8 lens, or better yet, there are no light restrictions to favor the center point, it can still give a more accurate result because it is the intersection point.
When we look at the focus point rectangles, it's worth remembering that the real area of the sensor is 2-3 times larger than what is displayed. Keep this in mind as you focus. If you fix the focus on someone's bridge of the nose, remember that the person's eyes will also fall into the active area of the sensor. Autofocus will lock on to the eye rather than the bridge of the nose because the eye has more edge contrast than flat lighting on the nose. Often this may not matter, but if you are working at a very shallow depth of field, you will feel the difference in which area of the image is most sharp.
3. Lend a helping hand to your lens
Most autofocus systems have a certain amount of errors or deviations and may actually miss the point of optimal focus due to the mechanics and inertia of lens movement. You can minimize this effect by manually focusing the lens as close to the desired focus as possible, and then let the autofocus system finish focusing. Or, if this seems too difficult for you, at least let the autofocus make two attempts to achieve correct aiming. Half-press the shutter button to set the approximate focus, and then press again to fine-tune it.
The advantage of lenses is more high level in that they allow full manual control even when autofocus is locked. Cheaper lenses do not allow manual focus adjustment after locking, although this good way make sure the focus is as perfect as it can be.
4. Find a good line
Autofocus systems work on contrasting lines, so they may struggle on subjects with low contrast (eg cheek or forehead, white dress or black tuxedo, sand, monochrome walls, etc.). In areas like these, autofocus can go all day long and never lock. The approach is to find the "best line" - it could be the eyes, the lines between the contrasting shirt and suit, between heaven and earth, the doorway. Anything with contrast will help autofocus work better and faster.
Low Focus Zone
Best Area to Focus
5. Don't use all-point focus mode
Unless you're in a terribly fast-paced situation that requires incredibly fast aiming, it's best to avoid all-point focus mode. This mode doesn't know what you want to focus on and is usually fixed to whatever is closest to the camera. There are situations in which this is exactly what is needed, but they are few and far between.
6. Focus and recompose - but do it the right way
I'm used to focusing and recomposing using the center focus point all the time. I lock the focus and then recompose the shot. I once read a few articles that said you shouldn't do this - that you should use the point closest to the area you want to focus on. Theoretically, this is justified by the fact that during the movement of the camera, due to the movement of the lenses and the change in the angle value, the distance between the subject and the lens also changes.
If you use a focus point directly on the subject and do not recompose the frame, there will be no change in the distance between the subject and the lens, and therefore erroneous focusing. So, I decided to take some pictures to show you that it is - and it is not.
There was absolutely no advantage in using the nearest non-center point without changing the composition. In fact, focusing using the center point and recomposing was, indeed, more accurate in all cases except for one - macro. I took shots at all focal lengths from 17mm to 200mm and checked all distances from macro to 10 meters - with the same results.
Each test using the center focus point and recomposing the frame resulted in a sharper picture. Greater sharpness from using the center point and recomposing, less sharpness from using an outer focus point right on the subject. To clarify, the above theory is correct, in that you lose sharpness by moving the frame away from a fixed center point. What's not true is that using an outer point directly on the object will bring back sharpness - it won't.
I think there is a good chance that on my camera the center focus point is three times more sensitive than any of the other eight points, and it is this one that is most accurate. But so is the case with many cameras, with the exception of high-tech new models like the Canon 1Ds Mark III or Nikon D3X. Other possible the reason is that most lenses are sharpest in the center and lose sharpness towards the edges.
Here are three of the most typical examples of what I shot on two different cameras. An insert is an inscription on a scale of 100%.
Center focus point, no composition change. Lens 50mmf 1.8.
Lens 50mmf1.8. Central focus point. The camera is moved to the left after fixing the focus.
Lens 50mm f 1.8. Left focus point. Focus on the object.
What can I say - whether to switch the focus point or not, in my opinion, is a matter of time. But try it yourself, your result may differ.
A small note on macro - such shots should always be taken with a tripod and manual focusing, due to the extremely shallow depth of field and the proximity of the lens to the subject.
7. Use the correct focus mode
Most DSLR cameras have at least two similar focus modes. The first is "One Shot" (Canon) or "Single Servo" (Nikon). This mode assumes that the object is stationary. Focus locks, you get lighting confirmation on the internal display, and then you release the shutter. You will not be able to release the shutter if the focus is not locked.
The second type is “AI Servo” (Canon) and “Continuous Servo” (Nikon). This mode is suitable for shooting subjects in motion, including sports events, wildlife etc. The camera finds the subject using the focus point, and the focus will constantly change to keep up with the subject, but will never lock. The shutter button will work even if the focus is not perfect.
There are also other modes on some cameras, such as Canon's AI Focus, which are great when the subject is static but may start to move, as is the case with young children. Autofocus will lock on the subject, but if the subject moves, the camera will enter AI Servo mode to track it.
The third option, pre-focus, is for objects that are moving towards or away from you. The camera will try to predict the movement and give you an acceptable focus.
8. Don't change depth of field for good focus
Although using a larger depth of field with a smaller aperture can increase the "apparent" sharpness of an image, remember one thing: no matter what the depth of field is, there is only one point of focus. So always practice good focusing techniques no matter what depth of field you use.
9. Use a tripod or find a foothold
When we take a photo, we all unconsciously sway back and forth - in particular, leaning towards the subject with a heavy camera and lens kit. It `s naturally. Everyone has it to one degree or another. And if you're shooting with a very shallow depth of field, that small amount of distance you shift can have a big impact on the sharpness and the sharpness of focus you want. If you're using a 4" depth of field, a 2" offset can have a disastrous effect. So use a tripod.
Now I have to add, since I use a tripod myself - I hate them. They affect the way I work and, most of the time, the way I shoot. So, if you prefer to avoid using a tripod, at least take the time to practice your position. good photographer. One foot in front of the other, legs slightly bent, arms pressed to the sides, not dangling in space (remotes can come in handy here remote control), and the weight of the body is distributed centrally over the legs.
10. If still unsuccessful - use manual focus
I hear a deep sigh every time I offer this to photographers. They regularly state, "I shoot only in manual mode, never on automatic." But offer them one more time manual focus, and they will look at you as if you just offered them to sell their children. Manual focus in most cases (given that your diopters are set correctly) will help achieve the best and most exact result. Especially in this digital age, when it's so easy to see an image at 100% or even 200% magnification on our monitors.
In fact, if you look at the unofficial autofocus specs, you'll notice that they aren't very accurate. Here is the specification for "sharpness": An image is considered sharp if it appears sharp in print 6x9 from a distance of 10 inches. Yep, that's it. No 100% zooms, no 20x30 prints. Just this.
Today, a number of new cameras are being produced with a built-in Live View mode. It could be useful tool at manual focus. Turn on your Live View, zoom in on the subject/focus point and check the sharpness on the display. This doesn't work very well in my case since I'm almost always in the conditions bright lighting: deserts, beaches, etc. - but for some it will work just fine.
One note about the image above. I usually use it to show the manual focus switch, but the other switch is also of interest: "1.2m to infinity" and "3m to infinity". This switch is related to what I was talking about earlier: don't make your lens hunt for focus through as much space as possible. If you know you won't be focusing on anything closer than three meters, move the lever to the appropriate position and the lens won't have to wander around looking for focus. This can result in more accurate primary auto focus.
11. What should I focus on?
For close-up portraits, the consensus is, in general, worked out: the eyes. For other types of portraits, it's still the face, unless you intentionally want to focus on some other part of the body. Focus precisely where you want the viewer's eye to go.
Landscapes aren't always easy, but you still need to stick to the rule mentioned above. Do not bet on the fact that "this is a landscape with a wide viewing angle, focus on infinity." If you have a subject in the foreground, focus on it and let your depth of field bring the image into the background. If the object in the foreground is not in sharp focus, it is confusing, because in natural conditions we usually see objects that are closer rather than distant ones.
I can now work with focusing at "Hyper Focal Distance", but that's out of the scope of this tutorial. If you are interested in this topic, which is likely, use a quick Google search.
12. Is the subject in focus, but is it sharp?
Focus and sharpness are two different things. Explaining the concept of sharpness can take another lesson of its own, so I'll just point out a few useful points.
If an image is out of focus, you cannot bring it back into focus by sharpening it. You will only get a very sharp out-of-focus picture. Most RAW images need some sort of sharpening. Whether you're using Smart Sharpen, Un-sharp masking, or high pass filtering techniques, most RAW images benefit from sharpness. However, as I gradually started using higher quality cameras, I saw less and less need for sharpening, and now I only use this tool in about 25% of my frames.
Remember also that sharpness depends on the final product. You won't sharpen in the same way on an image that goes to the web as you would on a 16x20 print. And with that in mind, if you intend to sell your photo through a stock agency, don't sharpen it at all. Most will tell you not to do this because you can't predict what the image will be used for and at what size.
On the left are images directly from the camera, unedited ("Straight Out of the Camera"), on the right - with added sharpness.
13. Consider exposure
Shutter speed is another setting that can lead to a lack of sharpness. Each person has a limit on the shutter speed at which he can shoot handheld on lenses with different focal lengths. Some people are more stable than others, but if you're shooting at a shutter speed that can't compensate for the movement (trembling) of your hands, your image will come out blurry. When it comes to standard and wide angle lenses, most people can shoot handheld with them consistently at around 1/30-1/60 of a second.
Larger telephoto lenses require much faster shutter speeds. General rule, which people start with: "1 to the focal length of the lens". So, if you have a 200mm lens, shoot at 1/200th of a second, and start from that level to understand your further possibilities. Personally, I'm shaking like California on its worst days, so I usually shoot for more short exposures. It also depends on how far away you are from your subject, as the farther you are, the more noticeable the movement.
If the subject is moving, keeping the camera stable or on a tripod won't help - you'll still need to choose a satisfactory shutter speed in order to stop the action. Most start at 1/250, but it depends on how fast the object is moving. The requirements also vary depending on whether you are shooting in a static position or following the subject. If the latter, you can choose more long exposure and also get some cool effects. This will allow you to show movement in the background, but will freeze the object itself.
Image stabilization systems on lenses allow you to shoot handheld at faster shutter speeds (up to 3 stops), but will not "stop" movement any better than a lens without an image stabilization system. You can only capture the action with a shutter speed (or high-speed flash).
Image not out of focus. The shutter speed is too long.
14. Choose the right exposure
Correct exposure and good lighting (the essence of all photography) is the key to good focus and sharpness. While sharpness is determined by the line of contrast, if you underexposed the frame or shot in dim light, the image will not be sharp even if all other parameters of good focus are met.
15. I did it all. I'm still out of focus!
There is a small chance that something is really wrong with your hardware. Third-party lenses are sometimes not very well designed, and therefore will not always work perfectly with branded cameras. Some work great, others don't. But sometimes even branded lenses are not made perfectly.
Cameras like the Canon 50D and 1D/Ds Mark III have excellent front- and back-focus fit for over 20 different lenses, so if you know one lens is perfectly focused in front of your subject all the time, you can adjust the camera. to fix it. If this option is not available, you need to determine if your lens, or both lens and camera, needs repair.
Here's a test you can do at home to see if it's you or the camera. Find a ruler and place it on the table away from the camera. Put the camera on a tripod and open the aperture as wide as possible. Take a picture of the ruler at a 45-degree angle, focusing on a specific mark - in this example, the six.
If this is the mark that you will see as clearly as possible when you open the image, then everything is in order with your equipment - get back to working on your technique! If the sharpest point is before or after this mark, then you will know that this is a hardware problem and should be taken to service.
16. Conclusion
I covered a lot of questions in this tutorial - great that you read to the end! I think that good focus and sharpness are two of the most important technical parameters to be saved in the image. This can make a difference between shots that look professional and those that look like amateur work (and we all want to look like professionals - whether we are or not).
Please feel free to leave your opinion in the comments - have you ever had problems with focus and sharpness?
Many amateur photographers, having received a new camera, immediately begin to use it for its intended purpose - they shoot everything and a lot. After some time and hundreds of shots, some people start to wonder how their camera works. For many, the real discovery is the possibility of using autofocus control.
Focus is one of the most creative tools in photography. This is the power to draw the attention of your viewers to one specific object from all around the world, and it's just incredible. Below are some tips to help you take control of your new camera's autofocus. They are suitable for both DSLR and mirrorless cameras, but the names of the menu items may vary from model to model.
Cameras do not focus on objects
The first thing that helps you understand autofocus is realizing that cameras don't focus on trees or basketball players or mountains or any object at all. Cameras focus at a certain distance, and everything that is located at that distance from the camera will be in focus. If a person who is two meters from the camera is in focus, then all other objects located at this distance will be in focus. Picking up a new camera and pressing the shutter button halfway to focus, you will see a lot of illuminated squares (or dots, depending on the camera model) in the viewfinder. This does not mean that the camera will focus on all these points, this indication only shows which objects in this moment come into the camera's field of view. It often happens that most of these squares (or dots) do not fall on the objects that you would like to focus on. Let's see how to fix this.
The camera focuses at a certain distance and everything within that distance will be in focus. In this photo, the camera is focused on the area where the dog's face is located. Since the girl is behind this distance, her image is out of focus.
Focus Area Mode: Single or Manual
In order to match the focus to the objects you would like to focus on, you need to change the focus area mode. The default settings give you all these squares (dots) lighting up randomly. By changing the focus area mode to Single or Manual, you can choose in which area of the viewfinder the AF point should be selected. Area selection will be available using the arrow buttons or the dial on the camera. On some camera models, in order to access the ability to change the focus point, you will first need to press a special button.
Select focus area AF-S
By choosing a focus point, you can choose the distance at which the camera will focus
If you let the camera choose its own focus area, you won't be able to predict where it will focus.
Focus Mode: One Shot or AF-S
Once you have control over the camera's focus area, you should select a focus mode. Most cameras default to a mode that determines whether the subject is moving in the frame or not, and adjusts the focus accordingly. This mode may be called AF-A, or AFF or AI Focus. However, this mode has a disadvantage. For example, when we focus in one place and then move the camera to change the composition, this autofocus mode interprets the movement of the camera as the movement of the subject and adjusts the focus according to this data. As a result, the subject in the image may be out of focus. So you need to use this mode very carefully.
In order to get sharp images in most cases, it is preferable to use the single-shot autofocus mode, most commonly called AF-S. In this mode, the camera focuses on a point in the viewfinder and maintains focus there as long as you keep the shutter button half pressed. The focus does not change even when the picture is recomposed. This focus mode will allow you to get a much higher percentage of sharp shots.
In this shot, objects were moving towards or away from the camera, so the AF-C / AI Servo mode worked very well.
Another focus mode, AF-C or AI Servo, is for shooting moving subjects that may get closer or further away from the camera. When using this mode, you must be sure to keep the focus point on a moving subject. Even if you keep the focus point on your subject's eyes, this mode is not recommended for portrait photography, as the camera will constantly adjust the focus a little bit, waiting for your subject to move, which usually results in images that are not sharp enough.
In this shot, my model was sitting still, so the AF-S / One Shot mode was perfect.
In some cameras, you can find other focus modes, such as 3D tracking and face detection, etc. They may show nice results in some situations. But most of the time AF-S/One Shot will the best choice For you.
Not all focus points you see in your camera's viewfinder are equally effective. The center focus point is usually more accurate. It is more sensitive, and can actually do a better job than dots located in outer areas. The center point is always a cross type, which means it works better in low light conditions. In addition, your lens is brighter in the center, which also makes the focusing process easier and more accurate.
AT similar situation it will be difficult for the camera to focus on the dark faces of people in the foreground, so focusing on the center point is a great option
To understand which autofocus mode to choose, you must first understand what you are photographing. Autofocus modes and settings on all cameras are about the same. They may differ in name and be managed differently, but the principle is the same everywhere. So what is autofocus?
First, make sure you have autofocus turned on. On advanced cameras (Nikon / / D7000 / D7100) there is a separate switch on which there is an M (manual focus) mode and some other modes - different autofocus, or simply AF.
The M (Manual) mode works the same way cameras did in the 50s, that is, without autofocus. If you do not have such a switch, then the autofocus modes on your camera are controlled through the menu.
In addition, autofocus lenses with a built-in motor (AF-S) also have an autofocus switch, very often marked M / A - M. Make sure that the lens is not in manual mode either. Do not confuse the AF-S lens type with the AF-S autofocus mode, they are different things, although they are called the same thing.
Autofocus modes are as follows:
AF-A (Auto). Automatic mode, in which the camera decides for you how to focus. If you are not sure which mode you need, choose the automatic mode.
AF-S (Single). Mode for static scenes. In this mode, the camera focuses once when you press the shutter button to the middle, and that's it. The camera no longer focuses until you release the button. Great for landscapes and portraits.
AF-C (Continuous). Tracking mode, where the camera constantly follows the subject and adjusts autofocus continuously until you release the shutter button. Turns on when you press the shutter button halfway. This mode is great for photographing wildlife, sports, and fast-moving children.
In the Custom Settings Menu, in the Autofocus section, you can find AF-S / AF-C priority selection.
Release is the shutter release immediately, even if the image is not at all in focus. I hardly remember ever having sharp shots in this mode.
Focus- The shutter only works when the image is strictly in focus. This is very slow and you risk missing a frame.
I recommend value release+focus for AF-C, it's something in between. Even if the first frame is out of focus, the next ones will be much better in continuous shooting. In this case, you will not lose the first frame, although it will be a little blurry. Focus is good for AF-S because nothing moves in the frame.
In addition, you still have to choose the type of autofocus area.
Nikon usually offers three options:
Conditionally, the areas can be divided into two types:
Multiple sensors (AF-Area). Focus information comes not only from the sensor you have selected, but also from the surrounding points, and the surrounding sensors are not highlighted in any way. For example, on the Nikon D7000, you can select a zone from 9, 21 or 39 points. Usually, the faster something moves in the frame, the more area is required. To be honest, I don't use these zones, I prefer 3D-tracking.
3D tracking. This mode can be on some models along with a white rectangle and a crosshair, on other models somewhere else, for example, when choosing the size of the autofocus area. As the name implies, this is a tracking mode, and when tracking, not only the distance to the object is taken into account, but also the color. You choose a focus point, autofocus clings to what is under this sensor, and then starts to follow it if the subject moves or you turn the camera.
The fundamental difference between AF-Area and 3D-tracking is that in the first case, the camera focuses on what falls into the selected autofocus area, and in the second case, the camera itself moves the area behind the object, switching autofocus sensors. Therefore, in 3D mode, it is very convenient to focus on something specific, then move the camera to frame it differently, but autofocus will still focus on what it was aimed at initially. This differs from the AF-S mode in that AF-S is not aware if the object moved further or closer during framing, or even flew out the window.
In addition, 3D tracking can even replace single focus point selection. Instead of going through the points with the selector until you get to the one you need, you can simply visit the center in 3D mode and then crop it as you need, while the camera will keep focus on the object, moving the focus point, switching autofocus sensors. The object, at the same time, will not be able to escape from autofocus.
Keep autofocus in auto mode (AF-A, white rectangle), this mode will work fine in most situations without your help. If the work of autofocus did not suit you in any particular case, then start thoughtful settings.
That's all autofocus.
