What subjects are suitable for shooting AV files in photography?

What subjects are suitable for shooting AV files in photography? Av files, namely aperture priority mode (Canon is AV, Nikon is A), belong to semi-automatic shooting mode in cameras. Select the aperture (aperture value) and the camera will automatically calculate the shutter speed to get the "correct" exposure.

▲ Aperture priority mode

In order to further understand the aperture priority mode, let's review the basic knowledge about aperture and exposure.

Aperture: Aperture is an opening (hole) in the lens, which is used to control the amount of light passing through the lens. Such as f 1.4, f2.8, f 1 1, etc.

▲ The smaller the aperture value, the larger the hole. The larger the aperture value, the smaller the hole, which is inversely proportional.

The main function of aperture is to control the depth of field and exposure: the larger the aperture value, the shallower the depth of field and the smaller the exposure; The smaller the aperture value, the deeper the depth of field and the greater the exposure.

Three elements of exposure: the exposure of a photo is determined by the interaction of aperture, sensitivity and shutter.

▲ three elements of exposure

Key point: Changing one of the factors will affect other factors, that is to say, you can't just consider any one of them alone, and you must always pay attention to all the parameters in your mind when making adjustments.

So, what subjects are AV files suitable for shooting? 1, large aperture-protruding body

Aperture can control the depth of field, so aperture priority is mainly used in shooting occasions that need priority depth of field, such as portraits, landscapes, macro and so on. At this time, the subject is usually required to be "eye-catching". At this time, you can choose the large aperture of the lens through the aperture priority mode, such as F2 and F2.8, combined with long focal length and close-range shooting.

▲ In portrait shooting, a large aperture is often used to blur the background and highlight the subject.

▲ Close to shooting to create a shallow depth of field.

2. Small aperture-clear distance

Small aperture can produce large depth of field, which can make far and near scenes clear. Therefore, when shooting still life, scenery, portraits and other subjects, try to choose a lens with a small aperture, such as F 16 and F22. Of course, shooting with a small aperture will slow down the shutter speed, and a tripod is often needed to stabilize the camera.

▲ A small aperture can produce a large depth of field, which can make distant and nearby scenes clear.

It should be noted that sometimes even a small aperture like f/ 16 cannot keep a photo in focus from front to back, so it is necessary to use depth of field synthesis technology. Please refer to the big move to break through the lens limit and create infinite depth of field, including the pre-shooting and post-tutorial of depth of field synthesis.

3, small aperture-shoot stars.

When the aperture of the lens is reduced, there will be diffraction phenomenon-light will be diffracted by the lens blade, resulting in starlight. The smaller the aperture, the better, sharper and clearer the star.

▲ Small aperture, shooting the stars of the sun, the sunlight penetrates the leaves to be brighter.

Please refer to the large-scale Star Mountain mentioned above for the shooting of Star Mountain, which should be shot like this! Introduction to the shooting skills of gorgeous "Star Mountain"

4. Low light environment

For example, in rainy days, indoors, or at night, aperture priority can also be used, because in this case, it is often necessary to brighten the whole picture, but if the shutter speed is adjusted to brighten it, once the shutter speed is too low, it is easy to blur the picture. On the contrary, fixing the aperture value at the maximum value can not only supplement the light, but also maintain the clarity of the picture to a great extent.

▲ In low light environment, a large aperture brightens the picture and reduces the chance of jitter.

5, charming lens (spot) effect

Generally speaking, the larger the aperture of the lens, the more obvious the shooting. In other words, a large aperture is easy to have a lens, because the larger the aperture, the smaller the depth of field, and the more Jiao Wai areas, the stronger the shooting effect; Conversely, the smaller the aperture, the greater the depth of field, the smaller the defocus range and the weaker the defocus.

▲ But in practical application, the bigger the aperture, the better. It is true that the larger the aperture, the larger the "head" of the astigmatism point, but if the number of point light sources in the background is large and densely distributed, the larger the aperture will make the astigmatism points overlap each other, which is not very beautiful, as shown in the following figure.

▲f/ 1.8, the light spots are greatly blurred and connected together.

In this case, the effect may be better if the aperture is slightly narrowed, so that the light spots are separated from each other, the outline is clearer, the number is more, and the brightness is higher:

▲f/3.5, the light spots are separated from each other, the outline is clearer, the number is more, but the effect is better.

What should you pay attention to when using aperture priority mode 1? Always pay attention to the shutter speed: the most direct response to aperture adjustment is the shutter speed. The camera will give a suggested shutter speed according to the luminous flux, and it is impossible to carefully judge the shooting environment at that time, such as low light environment. The camera may give a speed lower than the safe shutter according to your aperture, resulting in hand shaking.

▲ Use tripod in low light environment to avoid image jitter.

2. Exposure compensation: In semi-automatic mode, the camera will automatically calculate the "correct" exposure. If we don't recognize this exposure value, we can use exposure compensation to increase or decrease the exposure. The simplest method is to judge whether to make positive exposure compensation or negative exposure compensation according to the formula of "white plus black minus".

▲ In order to make the flowers stand out, a darker shooting environment was selected, and the exposure compensation was reduced by 0.3, so that the bright flowers stood out with a darker background.

3, the best aperture: I believe many people have heard that "it is best not to use the maximum aperture of the lens when taking pictures, so as to avoid loose imaging of photos; If the aperture is too small, the imaging will be reduced. " In a certain aperture range, the imaging quality of the lens is the best, and this aperture range is called "optimal aperture". Every shot is different. According to the different optical design of the lens, we generally think that the aperture 2-3 levels smaller than the maximum aperture is the best aperture of this lens.

▲ Best aperture of lens

If the above content is helpful, please like it and leave a message! Want to know more about photography skills, welcome to pay attention to ink printing.