A required course for introductory photography: What is an aperture?

There are more and more people who love photography, but many players who are just getting started have very shallow concepts about the common camera parameters. The theme of this issue is aperture. Aperture, shutter, and ISO are the core points of photography, and beginners may not know what effect the aperture has on the picture. What is an aperture today?

1. Popularization of knowledge: what is the aperture?

Aperture is a device used to control the amount of light passing through the lens and entering the photosensitive surface of the body. It is usually inside the lens. We use f-number to express the size of the aperture. The current aperture is mainly divided into three types, fixed aperture, cat-eye aperture and iris aperture.

The lens we are currently in contact with uses an iris diaphragm, which is composed of multiple overlapping arc-shaped diaphragm blades, and the more the number of blades, the closer the aperture of the iris diaphragm is to a circle. If you feel that it is not straightforward enough, you can refer to the picture, which is a typical and common iris diaphragm composed of diaphragm blades.

There are two main ways to write the aperture value, one is F1.2, F2.8, F4, and the other is f/1.2, f/2.8, f/4. The smaller the value next to F, the larger the aperture; the larger the value, the smaller the aperture. Pay attention to this.

2. How to identify the aperture configuration of the lens?

Many beginners do not know how to identify the aperture configuration of the lens when buying a lens, so there is a risk of being fooled by the merchant. Next, I teach you how to understand the aperture configuration on the lens. In fact, it is very simple, it is the F value written on the lens, this F value will only write the maximum aperture value of the lens. The aperture configuration of a general lens is divided into two types, one is a constant aperture lens, and the other is a variable aperture lens.

Let me talk about the constant aperture lens first. The logo of a constant aperture lens is very simple, that is, it directly indicates the maximum aperture value of the lens, and it is a fixed value, such as F1.2, F2.8, F4 and so on. For the lens, such as 1:1.2, 1:2.8, 1:4. Constant aperture lenses are usually relatively high-end products, such as Canon red circle lenses, Nikon golden circle lenses and so on.

Let’s talk about variable aperture lenses. This type of lens is usually based on entry-level to mid-range lenses. That is, the maximum aperture of the lens is not constant and will change with the change of focal length. For example, an 18-55mm f/3.5-5.6 set of camera head has a maximum aperture of f/3.5 to f/5.6. As the focal length increases, the aperture will become smaller, and 1:3.5-5.6 will be written directly on the lens.

3. How to adjust the aperture on the camera?

Introduced the aperture on the lens, then how to adjust the aperture on the camera?

To adjust the aperture value, you need to use the camera’s AV gear (aperture priority gear) or M gear (manual gear). Generally speaking, the pulsator on the top of the camera can directly adjust the aperture value (mainly SLR cameras and some mirrorless cameras) ); If it supports touch (no matter whether it is SLR or micro-single or card), you can tap the aperture display area on the screen, and then you can change the aperture value by sliding.

The micro-single and card cameras that do not support touch screens can be adjusted directly by using the pulsator on the fuselage in AV mode. In M mode, you need to click the switch button to change to the aperture value before you can use the pulsator to adjust, which is more complicated.

Because today’s cameras generally support touch operation, adjusting the parameters is particularly simple, just like using a mobile phone.

4. What is depth of field? How does the aperture affect the depth of field?

What is the depth of field, too professional words will not be introduced, and everyone cannot understand it. In layman’s terms, the depth of field is the degree of blur or clarity of the foreground, background, etc.

Aperture is a direct parameter that affects depth of field, so everyone should understand the effect of aperture size on depth of field. The specific relationship is as follows:

(1) The larger the aperture, the shallower the depth of field, and the more blur
(2) The smaller the aperture, the deeper the depth of field, and the less blur

We can easily understand the relationship between depth of field and some camera environment and aperture. We often see some large scenery films or exquisite photos during travel. In fact, it has a lot to do with the factors mentioned above. Through adjustment, we can grasp the relationship between these aspects and the blurring of the picture, thereby controlling the overall feeling of the picture and shooting more blockbusters.

5. What are the applications and effects of large aperture and small aperture?

For photography beginners, there will be a lot of problems in the realization of too advanced shooting operations at the very beginning, so the subject of shooting should start with the operation of the entry. For the function of large aperture and small aperture, as well as the impact on imaging, we mainly summarized four very basic forms of expression, which can be easily achieved by beginners and daily shooting.

5.1, blur

Blur is one of the most commonly used methods in photography. Blur uses the characteristics of large aperture. If the lens aperture is not large enough, you can also take advantage of the telephoto lens. If there are neither, it will be difficult to achieve an excellent blur effect. The purpose of blur is to highlight the subject in the picture by blurring the foreground and background of the picture. It is generally used for close-up and portrait photography. If it is a conventional wide-angle or medium focal length, there is already a good blur effect around F4; if it is a long focal length, F5.6-F8 can also achieve excellent refinement effects.

5.2 Light spot

The light spot is actually a branch of the blur effect. When shooting, if a large aperture is used, and there are some light sources in the foreground and background, such as lights, reflective bright spots, etc., light spots will be formed. In theory, the larger the aperture, the more obvious the effect of the light spot. However, too large aperture may cause the spot size to be too large, and the viewing effect is not obvious. In addition, the light spot is not only shot at night, it can still be shot during the day.

5.3 Starlight

Astral, the main use of the small aperture of the lens to shoot the picture effect. Many people think that shooting stars requires the use of long-exposure shooting techniques. In fact, it does not take a few seconds or tens of seconds to achieve the effect of stars, and a very obvious starburst can also appear with an exposure of about 1 second. Generally speaking, the smaller the aperture, the better the effect of shooting starburst. The theory is that the aperture of F8-F11 can show the starburst effect.

5.4 Traffic flow, water flow

Another small aperture application, and the most common photography technique, is to use long-time exposure operations to capture the motion trajectories of objects, such as traffic flow, water flow, and so on. When shooting this kind of picture, the exposure is a few seconds to 30 seconds, and then it is recorded with an F8-F16 or even smaller aperture, so that the trajectory of the object’s movement can be recorded.

If beginners are interested in high-end operations such as shooting the starry sky, galaxy, changing the spot shape, light painting, etc., we will introduce them separately in the subsequent tutorial articles, so stay tuned. Basically, our most common applications and effects of large and small apertures are these. Beginners can start practicing from these four.

In fact, the application and gameplay of aperture are still very rich, but for beginners, what should be mastered is the most basic collocation, such as what kind of shooting technique needs to match how many aperture values. When you are proficient, you can advance to experience more advanced photography skills. These seem to be very simple, but every beginner has learned this way. There are no shortcuts to photography. Everyone needs to come step by step and come on.

About Yalong

I like to write articles about digital products and digital life, and believe that it is these products that ultimately change people's lifestyles.

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