What are the functions of the fixed-focus lens?

First of all, the fixed-focus lens has great advantages for autofocus cameras, and the focal length of the zoom lens can be adjusted at any time, which will weaken the ability of fast focusing to some extent. When you adapt to a fixed focal length, the sensitivity of the focal plane will also improve, and you will easily judge whether your subject is out of focus, which will also be of great help to improve your ability to judge the focus.

We often say that the fixed focus basically depends on walking. Although zooming is easy for us to lengthen and shorten the focal length, it brings not only the change of focal length, but also the distortion, which is very serious at the wide-angle end and telephoto end. Generally, the cheaper zoom lens can't correct these distortions well, and for many novices, it doesn't have the ability to predict them.

Compressing space by focal length change

When using a fixed-focus lens, you don't even have to look at the viewfinder all the time. When you are familiar with a focal segment, you will know the picture covered by this focal segment, and you don't need to look at the viewfinder repeatedly. This is very useful in street shooting. Many times, in street photography, we don't have much time to hold the camera in front of us, adjust the focal length, focus, composition and then take pictures. Many pictures are often taken in an instant, not to mention those moments when it is inconvenient to hold the camera. Using fixed focus, we can easily predict the focus by the depth of field ruler. Muscle memory will help you take a photo at waist level, focus in a very short time, and press the shutter to complete a shot.

Everyone should be familiar with Capa's famous saying: If you don't shoot well enough, it's because you're not close enough. It is true that zoom lenses can easily zoom in on the pictures, but these pictures always seem to be very detached from the theme and heartless. Instead, you need to rely on your steps to force some reactions and make the composition full of emotion. Compared with the design of zoom head, the fixed focus head will be smaller and lighter, and you can take two zoom heads out of the street at will without feeling pressure. Because the design is compact, it will be less aggressive than street shooting, and the smaller the body, the less afraid it is.

Because of optical design, zoom lens rarely breaks through f/2, and f/ 1.8 of 50mm fixed-focus lens becomes the basic standard. In addition to Sony Zeiss' 55mm/1.8, N C's 50/ 1.8 can be bought for only a few hundred dollars. You can check the price of constant aperture f/2.8 of 2470 zoom lens to know how big the gap is.

Fixed focus lens can easily achieve a larger aperture, which will be very useful in low light environment.

Of course, the fixed-focus lens is not perfect. Its biggest drawback is its limitations. It sacrifices convenience, so you can only shoot in a fixed frame. Only when you can effectively and correctly construct the theme in your position will your fixed-focus lens be effective. Too close or too far, you can only escape. Maybe when you run, the picture you want to take disappears.

However, there will be progress only if there are restrictions. We will optimize the content to the maximum extent within the limits. We must rely on sports to change the composition, which will bring us more thinking and enable us to experience photography for ourselves.