Friends who are new to portrait photography often feel confused when faced with many "long guns and short guns": "Which lens is most suitable for portrait photography?" Generally speaking, a lens with a focal length of 16mm to 200mm can be used to shoot environmental portraits. The key is what kind of visual effect you want to create. In order to let us have an intuitive understanding of the focal length of the lens, let's do a simple experiment: let the model stand about ten meters in front of the forest, and shoot a portrait with Theory of Three Represents's ultra-wide-angle, medium-focus and telephoto focal lengths of 16mm, 85mm and 200mm respectively, and the aperture is set to F/2.8. We will find that the figure of 16mm is seriously deformed, the trees behind it are photographed the most, the forest has a feeling of being "pushed away", and the ambiguity of leaves is weak; At 85mm, the perspective relationship between the figure and the forest behind is close to what the naked eye can see, and the leaves are obviously blurred; The trees photographed at 200mm are the least, and the distance between the figure and the trees behind him is narrowed, which has a "sense of compression" and the blur is further increased. From this, we can draw a rule: wide-angle lens: it has a large angle of view, can shoot a larger scene, objects are near, far and small, the distance between vertical objects is pushed away, and the ability to blur the background is weak. Medium focus lens: natural perspective, similar to what the human eye can see, and its blur ability is obviously stronger than that of wide-angle lens. Telephoto lens: The minimum viewing angle can magnify distant objects, and the distance between vertical objects is "magnified", which has the strongest ability to blur the background. If we master this rule, we can use it flexibly in actual shooting and shoot pictures with different visual effects, thus highlighting the theme of the work. Wide-angle lens: use its wide viewing angle to show the big scene and shoot the atmospheric picture. In order to avoid large deformation, when shooting a portrait with a super wide-angle lens, it is necessary to avoid putting the character too close to the edge. Using the focal length of 16mm, the head and hands of the character are not obviously deformed because they are close to the center of the picture. Using the principle of perspective deformation, the subject can be deformed appropriately, highlighting the key points and strengthening the theme. Shooting with 24mm lens, because the lens is very close to the model's hand, the hand and pigeon become exaggerated, which has a visual impact of rushing out of the picture. In a vast scene, people and scenery are clearly displayed by using the weak fuzzy ability of the super wide-angle lens. When shooting with a focal length of 28mm, the details of people and scenery can be taken into account. Medium-focus lens: When shooting people with medium-focus lens, it is easy to appear "dull" because of its natural perspective and large viewing angle. Therefore, it is best to choose some distinctive scene elements to see the whole leopard and explain the environment. Although the 85mm lens can't capture more scene elements like the wide-angle lens, it clearly interprets the environment with dots and rattan leaves. The 85mm lens is usually called the "portrait lens", and manufacturers usually design a big circle for it, which can get an unreal Jiao Wai effect, especially useful when shooting female portraits. Telephoto lens: When the background or foreground is far away from the person and you want to emphasize the relationship between them, you can "compress" them together with a long focal length. Using 200mm focal length and 2x zoom lens, the snowy mountain opposite Sailimu Lake is greatly reduced, the picture becomes clean and the theme is more prominent. The foreground is only half as deep as the depth of field behind. When shooting with a focal length of 200mm, the plant blur in front of the model is particularly serious. The telephoto lens has a small viewing angle, so the photographer can cut the subject according to his own needs to form a "compact" picture effect and directly highlight the subject.