Characteristics of telephoto lens

Shooting with a long focal length lens has the following characteristics:

First, the angle of view is small. Therefore, the spatial range of the shooting scene is also small, and the shot image is larger than the standard lens at the same shooting distance, which is suitable for shooting the details of the distant scene and shooting the subjects that are not easy to get close to.

Second, the depth of field is short. So you can highlight the subject in a messy environment. However, this brings some difficulties to accurate focusing. If the focus is slightly inaccurate when shooting, the subject will be blurred.

Third, the perspective effect is poor. This kind of lens has obvious characteristics of compressing spatial depth and exaggerating background.

When using a long focal length lens, it is usually used to shoot distant scenes. Due to the absorption of air and the influence of diffused light. Therefore, it is not easy to achieve very accurate focusing because of the small contrast of the captured image and the serious extinction of dust particles. When shooting with a telephoto lens above 300mm, it is still difficult to focus all colors of light on one point, resulting in sub-spectral problems. Based on the above situation, sometimes the image quality of the shot works is not high.

Fourth, the longer the focal length of the lens, the more stable the camera must be to avoid image blur. The rule of thumb is that you can only shoot with the lens in your hand when the shutter speed is at least equal to the reciprocal of the lens focal length in millimeters, which is the so-called "safety shutter". That is to say, when the shutter speed is lower than1100 seconds, you can't shoot with 100mm lens, and when it is lower than 1/500 seconds, you can't shoot with 500mm lens. Most telephoto lens shooting work needs a tripod, so you have to carry not only the telephoto lens, but also the tripod.

Although the use of long focal length lens is influenced by many factors, its advantages are the main ones. It is widely used in many fields, such as shooting scenic figures, tourism photography, portrait photography (when shooting standard photos, use a common telephoto lens of about 100mm to reduce image distortion), shooting stands, sports scenes, shooting animals in zoos, shooting animals in the wild, and shooting close-ups with auxiliary mirrors.