Is what you see in the viewfinder of a SLR camera exactly the same as the photo you take?

Let me answer. Optical viewfinders are divided into two types. One is separated from the lens and is generally called an optical viewfinder (used in point-and-shoot cameras in the past). The other is through the lens and is generally called ttl. Viewfinder (mostly used on SLR cameras) Compared with LCD viewfinders, the first two viewfinders have many advantages. First of all, it can avoid excessive power consumption due to turning on the LCD, thereby extending the shooting time and battery life. Secondly, when shooting outdoors, it can avoid framing errors caused by reflections from the LCD screen. Detailed comparison of the differences between these three viewfinders:

1. Optical viewfinder No matter whether the camera lens is fixed focus or zoom, the viewfinder of the optical viewfinder remains unchanged. It works with The lens has nothing to do with it, it just mimics the angle of view and focal length of the lens. Most of the household point-and-shoot cameras (including household-grade digital cameras) use this framing method. The size of the viewfinder light hole determines the clarity of the image. For users who wear glasses, it is more important to have a relatively larger light hole, because the glasses will make their eyes farther away from the viewfinder. This makes it impossible to frame the scene accurately. Some viewfinders are now equipped with a diopter adjustment function, allowing photographers to take pictures more accurately without wearing glasses. However, only near- and far-sighted people can adjust the diopter. For photographers with normal vision, diopter adjustment is meaningless.

The optical viewfinder should be as close as possible to the center of the optical axis of the lens to reduce viewing parallax. Parallax occurs because the camera lens and viewfinder view the subject from different positions, so there are some differences in what they see. Generally speaking, the optical viewfinder cannot display 100% of the image captured by the lens, probably only 85% or less of the actual frame. This is why ttl viewfinder was developed.

2. TTL optical viewfinder

This viewfinder is usually equipped on more expensive digital cameras, and it can display the image captured by the lens. In traditional film cameras, the vast majority already adopt this framing method.

Different TTL viewing systems work in different ways. When used specifically, the details they can display are also different, but they all achieve this by reflecting or scattering the light passing through the lens. The purpose of framing. So for digital cameras that use TTL optical viewfinders, the images seen through the LCD screen and the viewfinder are consistent.

3. Electronic viewfinder

This viewfinder has the same advantages as the TTL viewfinder: it displays the entire scene to be photographed, can be seen in daylight, and can display aperture, Shooting information such as shutter speed, but in addition, the camera menu can also be displayed, which is not possible with other viewfinders.

The disadvantages of the electronic viewfinder can be summarized into three: unlike optical viewfinders and TTL viewfinders, it requires a lot of power; similar to LCD displays, it is easy to reflect light, thus affecting the accuracy of viewfinding; unlike optical viewfinders The system seems relatively rough in comparison. The last item is important because such a system cannot show the smallest details in the captured frame, such as whether the person's eyes are open, etc.