What's the difference between the lens lengths of SLR cameras?

Generally speaking, the lens used in SLR cameras has a long focal length and a short focal length.

Because of the long focal length, the requirements for images will be higher. In order to eliminate the need of distortion and aberration aperture, different lens groups are often added, which will inevitably lead to the lens becoming bigger and longer.

The shorter the focal length, the larger the viewing angle, and the more scenes covered by the shooting picture, that is, wide angle and super wide angle.

The longer the focal length, the farther the scene that can be "zoomed in", such as shooting birds at a distance. This is telephoto.

Maintenance of SLR lens:

1. Install the UV mirror:?

In order to protect the lens, you usually buy a UV mirror (installed outside the lens of the lens) when you buy the lens. UV mirrors can protect our lenses from dust pollution, and some UV mirrors are also helpful for shooting (such as nd mirrors). ?

2. Install the engine hood:

In addition to installing a UV mirror, a hood is usually installed in addition to the lens. The hood can not only prevent the lens from bringing in too much light and ultraviolet rays when shooting, but also provide buffer when the lens falls and protect the lens from too much impact. ?

3. Cover the lens:?

When the lens is not used at ordinary times, it is best to cover it or put it in the camera bag. Although it is protected by UV mirror, it will be dirty, so please cover the lens honestly. ?

4, pay attention to the use of matters:?

Never touch the mirror, image sensor and any other parts of the camera with your hands. Handle the camera carefully and get into the good habit of hanging it around your neck. After shooting, carefully wipe the dust on the camera surface with a soft and clean cloth in time. Please turn off the power switch when inserting or removing the memory card. Check the pin holes or contacts of the memory card regularly for foreign objects. ?

5. Clean the lens regularly:?

The maintenance of lenses is carried out according to the principle of blowing, wiping, washing and protecting, that is, keeping the lenses clean at any time. If it gets dirty accidentally, please clean the dust with a blowing brush/balloon first, and then gently wipe it with a soft and clean cloth. If it is not clean, you can gently wipe it with lens paper dipped in a little lens cleaning solution. If there is dust in the camera, please do not disassemble it yourself. Please send it to a professional shop for repair.

6. Reduce the number of lens shedding:?

Minimize the number of times you take off your lenses. When changing lenses, it's easy to get dirty things into the camera. When replacing the lens, be sure to turn off the power of the camera and avoid strong light and dusty environment. It is best to replace it indoors or in the car, and try to avoid replacing it in the wild, with the bayonet of the fuselage facing down.

7. Pay attention to the placement environment:

SLR cameras should not be stored in hot and humid places. Try to store it in a dry and ventilated place or a drying box, or put some desiccant in the camera bag to keep the humidity in the box at 35%-40%. Don't put the camera in the trunk of the car at ordinary times to prevent the camera from being damaged by low temperature or high temperature.

If you need to shoot in rain and snow, please be waterproof and try not to shoot in desert and other areas.

If the lens is taken from a cold environment to a warm environment, condensation may occur on the surface and internal parts of the lens. In order to prevent condensation in this case, you can first put the lens in a sealed plastic bag and take it out after it gets warm. On the contrary, please use the same method. Of course, a good quality camera bag is a good idea.