What does "wide angle" mean in photography?

Refers to the wide-angle lens of photography.

Wide-angle lens is a kind of lens, which has a wider angle of view and shorter focal length than general lens, and is often used to shoot objects with larger area.

Generally, the focal length of a wide-angle lens is 38-24 mm and the viewing angle is 60-84 degrees. The ultra wide-angle lens has a focal length of 20- 13 mm and a viewing angle of 94- 1 18 degrees.

Because the wide-angle lens has a short focal length and a large viewing angle, it can shoot a large area of scenery in a short shooting distance. Therefore, it is widely used to take large-scale landscape photos. In photography creation, shooting with a wide-angle lens can achieve the following effects:

First, it can increase the sense of spatial depth of photographic images.

Second, the depth of field is long, which can ensure that the scene before and after the subject can be clearly reproduced on the screen. Therefore, the vast majority of modern pocket automatic cameras (commonly known as fool cameras) use ordinary wide-angle lenses of 38-35 mm

Third, the lens covers a large area and shoots a wide range of scenery. wide-angle lens

Before introducing the wide-angle camera, let's know the focal length of the camera. In fact, when people talk about the focal length of a digital camera, they are not talking about the actual focal length of the digital camera, but about the equivalent focal length, that is, the focal length relative to the traditional 135 camera. From the principle of photography, the smaller the focal length, the wider the field of vision, and the wider the range of scenery that the photo can accommodate; The larger the focal length, the narrower the field of view, which means that you can shoot distant objects.

In traditional cameras, wide-angle lenses over 28mm are very popular. However, due to the particularity of small photosensitive devices in ordinary digital cameras, the physical focal length of the lens needs to be very short to achieve a wide angle, which leads to high requirements for aberration correction and anti-glare coating. With people paying more and more attention to wide-angle shooting, now around 3000 yuan, cheap wide-angle digital cameras are becoming more and more popular. Ricoh is the originator of a portable wide-angle digital camera with high cost performance. From G3/G4 wide angle to RX/GX series products, 28mm wide angle is its biggest selling point. In addition, Canon, Olympus, Konica Minolta and other cameras have also introduced 28mm wide-angle cameras.

For most popular digital cameras on the market, the wide-angle focal length is generally between 35 and 38mm. The real wide-angle digital camera is actually a product with a lens focal length covering a wide angle of 28mm. Because the wide-angle field of view of 28 mm is wider than that of 35mm and 38 mm commonly used in digital cameras, the wide-angle field of view of 28 mm is 76 degrees, while that of 35mm is only 62 degrees, so it can produce very unique visual effects and accommodate a wider scene. This is also the reason why consumers are more optimistic about 28mm wide-angle digital cameras. The biggest feature of wide angle is that it can shoot a wide range, with exaggerated sense of distance and wide focus range. When using wide angle, you can enlarge the object in front of you and narrow the object in the distance, and the surrounding images are easily distorted. Wide-angle can also adjust any point in the image to the most appropriate focal length to make the picture clearer, which can also be called complete autofocus.

Wide-angle digital camera has short focal length, wide viewing angle and deep scenery, which is suitable for taking photos of large scenes, such as architecture and scenery.

4. The scene shot at the same shooting distance is smaller in the picture than the scene shot with the standard lens.

Fifth, perspective distortion and image distortion are easy to appear in the picture. The shorter the focal length of the lens and the closer the shooting distance, the more obvious this defect is.

Wide-angle conversion method

In the era of 35MM film, the standard lens is about 50MM, which is close to the visual angle of human eyes, so it is called "standard" lens.

Greater than this value is usually called focal length, and less than this value is called angle.

Common names are as follows:

Focus angle appellation

17mm 180 fisheye

2 1mm90 super wide angle

28 mm 74 wide angle

35mm 62 quasi-wide angle

50 mm 47 standard

85mm, 28th medium coke.

105mm 23 medium focal length

135 mm 18 medium focal length

200mm 12 telephoto

300mm 8 long focal length

The calculation of its perspective is actually very simple. It is an isosceles triangle with the diagonal length of the photosensitive surface (rectangle) as the "bottom" and the focal length of the lens as high. You can calculate its vertex angle as the viewing angle.

In order to "understand" the lens conveniently, the lens usually uses data such as "34.5- 1449mm [4: 3] is equivalent to a 35mm film camera", and you can directly use it to calculate:

We know that the diagonal length of 35 mm film (36*24mm) is 43.2mm, and we can calculate its isosceles triangle. For example:

Let: the viewing angle is θ.

Then: tan(θ/2)=(43.2/2)/34.5=0.626

Calculate θ=64 degrees.