Defines the magnification of magnification photography, depending on

Depending on the resolution of the human eye, the resolution of the human eye at the apparent distance is 1 angular minute, and any surface smaller than this can be regarded as a point. The photo is for people to see, so the magnification is set accordingly. Under a proper magnification, the photo is clear only if the diameter of the dispersion circle does not exceed 1. Similarly, when the diameter of the dispersion circle exceeds the angle of1,the apparent distance will be unclear. At this time, the observation distance will be enlarged to make the diameter of the dispersion circle less than1angle, and the photo will be clear again. The concept of depth of field is also based on this.

The close-up ability of a camera/lens is determined by the focal length and the nearest focal length * * *:

-With the same focal length, the shorter the nearest focal length, the stronger the magnification;

-The nearest focal length is the same, and the longer the focal length, the stronger the magnification.

What if the focal length is different from the recent focal length? At this time, it is necessary to introduce "magnification": "magnification" refers to the ratio of the image formed on the photosensitive element to the original. The higher the magnification, the stronger the close-up ability of the camera/lens.

Generally speaking, the magnification of a professional macro lens is not less than 1: 1( 1.0 times). The "small macro" lens should also have a magnification of not less than 1:3(0.33 times).