How to use focusing skills correctly

Lead: Photography is a very substantial hobby, but it is really not easy to take good photos. If you want to shoot successfully, you must develop good shooting habits, such as finding out various focusing techniques. Let's talk about how to use focusing skills correctly, hoping to help everyone.

Single autofocus

When the camera leaves the factory, it is set to the default configuration, that is, you can keep focus by pressing the shutter. If the camera is set to single autofocus, all you need to do is activate the autofocus sensor and observe the viewfinder (assuming you only have one choice), and the focus of the important part of the scene will be clear. If you focus by half pressing the shutter, the lens will automatically focus on this point. Just press the shutter to take this photo. Although in most cases, you will want to change the composition. Press the shutter for half a time, you can recompose the composition in the way you like, and then press the shutter all the time to finish shooting. This focusing method is especially suitable for hand-held photography.

This method is inconvenient or useless on a tripod, because it is necessary to focus on the composition first, and then lock the tripod head, which slows down the shooting speed. The bigger problem is that you need to keep pressing the shutter button. For most cameras, if you point at the focus that you think is clear, such as deer's eye, and then re-compose it, and then press the cable to release it, the image may not be clear. The reason is that the autofocus sensor may be moved to change the focus from the face to a point in the background when the composition is re-composed. When you start to release the cable, autofocus is activated again, quickly focusing on the background and keeping the deer out of focus.

To avoid this possible problem, please check whether the release of your wired or wireless cable will cause the camera to refocus. If there is, the problem will be solved. Just turn off the autofocus button before exposure. Although the problem is easy to solve, it is also troublesome to turn autofocus on and off. Your camera may (hopefully) have a better solution than what we discussed.

Red foxes often chase mice and ground squirrels around our barn. This red fox is so used to us that it will come when we call it. On the river bank, throw a small piece of meat, and the red fox will jump up quickly, which is a good time to take pictures.

Continuous autofocus

This mode is very suitable for tracking moving subjects, because it will keep autofocus no matter whether the lens moves closer or farther. Usually continuous autofocus is on the camera body, which may be the choice of a switch or a series of buttons. Continuous autofocus can also be started by the shutter button.

For example, we used a 300 mm telephoto lens to photograph a black-and-white vulture hovering over the body of a Kenyan lion. Using the continuous autofocus function, when the vulture approaches, it is set as the autofocus center, and then it moves along with its flight trajectory to keep the autofocus point on it all the time. When it enters the viewfinder, you can get many pictures by pressing the shutter. Because the camera can automatically adjust the focal length when the distance of the subject changes, the chances of taking clear photos are greatly increased. Just be sure to use the shutter speed of11000 seconds. Following the theme of translation requires constant training to improve.

What about the autofocus sensor? Do you see it? Remove the cloud behind the subject, it will re-lock the new target, and then the vulture will lose focus. Using a large lens with an aperture of f/4 on the tripod, such as 600mm, has a very good follow-up performance. This kind of large and heavy super telephoto lens is impossible for ordinary people to hold effectively and needs to be installed on a tripod. Suppose you photographed a sandhill crane in a wildlife sanctuary. Use a heavy tripod to support the whole weight of the huge lens and the tripod head, so that the camera and lens on the tripod head can be successfully balanced, so that you can move in any direction without locking the tripod head. When the sandhill crane approaches, aim at it to start autofocus. As it moves and sees a good composition, you can press the shutter at any time.

I like shooting birds in flight. It's not difficult to practice more. Continuous autofocus will help you get a clear focus. There is also a common mistake that many people make. Suppose at dawn, the swan flies to the right of the reserve. However, first they have to pass through an area where humans are not allowed to enter, so they have to fly about 100 yards before entering the camera range. Once swans fly near, many people begin to track their tracks with autofocus, which is a good idea. When the bird flies close, follow the bird's trajectory, see the appropriate composition, and press the shutter as quickly as possible to take pictures.

So, what's the matter? Human nature instinct, from the beginning to maintain a balanced posture to follow the flying birds. Unfortunately, as the swan approaches, the shooting opportunity becomes better, but at this time, you will lose your balance, and it is difficult to maintain the speed of translation and shaking, and it is also difficult to maintain autofocus on the swan. Then, since you know where you want to shoot, you'd better keep a good balance at this point where you want to shoot, and then turn your legs and upper body in the direction where the swan flies. In this way, you will lose your balance a little at first, but as you follow the movement of the birds, you will just regain your balance when you really start shooting.

Autofocus usually focuses on the foreground of an object, such as the grass in front of this swamp rabbit. Using manual focusing, carefully adjust the focus to the rabbit's eyes.

Many cameras have a series of autofocus sensors to help you focus on irregular moving objects. This is called dynamic focusing. It does have advantages, but I prefer to choose a little focus (usually the central focus) and then follow the movement of the object to keep the focus.

Suppose you shoot a Canadian swan resting quietly by the pool, and the camera is set to single autofocus. Suddenly, the swan began to slide on the water, ready to fly away. This is a rare opportunity to photograph Canadian swans flying in all directions on the water. But if you use single autofocus, the bird will easily lose focus because you don't have time to refocus or switch to continuous autofocus.

In Samburu National Park, I once photographed an East African pronghorn standing under a tree with a focus button on the back of the camera. Since my camera has been set to continuous autofocus, keeping the focus button on the back of the camera can make me focus in time, so that I can shoot this running antelope that is catching up with the big army quickly.

Rear focus button

Like the problems encountered by the Canadian swan just mentioned, it is easier to solve if you use the focus button that few people know on the back of the machine. Many cameras have a button on the back of the fuselage that can start autofocus and turn off the focusing function of the shutter. Pressing the shutter button now will only activate the camera's metering function and start shooting. This function is usually turned on in the custom function, but it also varies according to the camera type. Many Canon cameras, custom function # 4 is used for control. Nikon D70 is in the custom function of # 15. Study your custom function settings carefully and find what you need.

It sounds inconvenient to control autofocus with the back key, but it will solve many autofocus problems. Almost all my Canon cameras are set like this, and they are often set to continuous autofocus. This allows us to quickly enter single autofocus or continuous autofocus. Next, let's talk about its working procedure. Suppose you are shooting a waterfall. Aim at the most important part of the waterfall, activate autofocus, and then use the back focus key to control the lens focus. Once the focus is accurate, release this button, even if the camera is set to continuous autofocus, the focus distance will be locked. Now you can re-compose, press the cable to release, or start timing shooting, all without refocusing the camera.

When shooting the Great Horn Elk Waterfall, the focus button on the back of the camera performed perfectly. In the viewfinder, only the middle autofocus is active. Aim it at the upper right corner of the waterfall so that the sensor will? Do you see it? Some white water and black stone, press the focus button on the back of the machine to determine the focus, release the button, re-compose, and then shoot.

In the example of just shooting the Canadian swan, you can set the autofocus on the swan's head, then use the focus button on the back of the machine to focus, release the button, re-compose, and finally shoot. If the swan starts to take off, as long as you keep following the swan's flight path and keep pressing the focus button on the back of the machine, you can control the shooting. Because the camera has been set to continuous autofocus, there is a chance to get a clear and sharp image.

In essence, you can quickly switch between single autofocus and continuous autofocus when using the focus button on the back of the machine to start autofocus. Another place to use the focus button on the back of the machine is a low-contrast scene or grass in the foreground. If you focus on the part with the most obvious contrast in a low-contrast scene, perhaps the trunk in the thick fog, press the focus button on the back of the motor to focus automatically, and check whether the lens in the viewfinder is focused correctly. Release the button again, re-compose, and shoot. While shooting a lion staring at its prey in the grass, focus on the lion's face exposed in the grass, press the focus button on the back of the machine to find the right focus, release the button and make a composition, and then you can take another sharp photo. Once you get used to it, you will find this kind of focusing method is very good. This is one of the most commonly used and best technical means in 10 years.

This system has a small disadvantage, that is, when pressing the focus button on the back of the machine, the shutter button must be pressed at the same time. Although it is easy to operate with more practice, I admit that it is easier to set the camera to continuous autofocus mode and keep the shutter control. One finger can control autofocus and complete shooting. We select this function when shooting only moving objects.

If the active sensor focuses on the top of the tree, autofocus will perform well. Will it? Do you see it? Contrast between the top of pine tree and the dawn sky.