The focal length of a digital camera is equivalent to 35mm. How many times the zoom does it mean?

Explain it in the simplest possible language, it may not be particularly standardized:

Equivalent to 35mm

1. The 135 camera (35mm camera) is what we used to Used old film camera.

2. When the focal length of a lens is equivalent to the diagonal size of the film, we call this lens a "standard lens" because its angle of view is equivalent to that of our human eyes.

Usually the focal length of a standard lens is about 50mm.

Lens with a focal length smaller than this, such as a 28mm lens, have a wider angle of view and are called "wide-angle lenses."

A lens with a focal length larger than this, such as a 200mm lens, has a smaller viewing angle but can magnify distant scenes (like a telescope), and is called a "telephoto lens".

3. Digital cameras no longer use film for light sensitivity. Instead, CCD (or CMOS) is used instead of film. But the size of CCD is usually much smaller than that of film.

For example, most household DCs are 1/2.3-inch CCDs. Then the focal length of its lens, which is similar to the visual range of the human eye and is equivalent to the diagonal length of the CCD, is much shorter, about 10mm.

The high-end card camera uses a 1/1.7-inch CCD, so its "standard lens" is about 12mm.

As for the 24.9×16.6mm CCD (APS-C SLR), its "standard lens" is about 35mm.

4. It can be seen that in the past, the sizes of rubber rings were uniform. When it comes to 28mm, it thinks of "wide angle". When it comes to 85mm, it thinks of "lens suitable for portraits". Photographers don't care. No matter which brand or model of camera you get (of course, 120mm cameras and large format cameras are not discussed here), you can always easily find the right focal length. But on digital cameras, it becomes confusing because of the different sizes of CCDs. In order to avoid this confusing situation, the real focal length of each lens is uniformly converted into "equivalent to the focal length of a 35mm camera."

How many times of zoom:

1. Because the telephoto lens has the ability to magnify the scene. The size of the image is directly proportional to the focal length. For example, if you shoot the same rock at the same distance and use a 100mm lens, the size of the rock will be twice as large as that shot with a 50mm lens.

2. Assuming the lens is 28mm-140mm, then the telephoto end can enlarge 140/28=5 than the wide-angle end, which is 5 times zoom. 24-120mm lens? Also has 5x zoom.