What does photo sharpness mean?

Sharpness, sometimes called "sharpness", is an index that reflects the plane sharpness and edge sharpness of an image. If the definition is increased, the detail contrast on the image plane is also higher and looks clearer.

For example, in the case of high definition, not only the wrinkles and spots on the face on the screen are clearer, but also the protrusions or depressions of facial muscles can be lifelike.

On the other hand, dark lines or black lines in the vertical direction, or places where black-and-white images suddenly change, in the case of high sharpness, the edges of lines or black-and-white images suddenly change more sharply, and the overall picture appears clearer. Therefore, improving sharpness is actually improving clarity, which is the good side that people need.

However, the higher the definition, the better. If the sharpness is adjusted too high, white lines will appear on both sides of the black line, and the image will look distorted and dazzling. If this happens on a block image, the image will be seriously distorted and ugly.

For example, when this happens on a small face image, not only the edges of the face will have white edges, but also the edges of black and shadow parts such as hairline, eyebrows, eyes, nose and lips will have white edges, which looks very uncomfortable. It can be seen that although the sharpness is too high, it will improve the clarity, but it will also make the graphics out of shape, which is also not a good thing.

Therefore, in order to obtain a relatively clear and true image, the sharpness should be adjusted appropriately.

Extended data:

Two aspects of photo clarity:

In fact, in the field of photography, the high definition of the lens is a double-edged sword. On the one hand, it makes the visual effect of the picture clear. On the other hand, due to the improvement of contrast, some unpleasant big details are enlarged and small details are covered, which leads to the decline of actual details and lack of hierarchy.

For example, in portrait photography, excessive sharpness makes the small scars and pimples of human skin magnified and prominent (that is, more obvious than what the actual naked eye looks like), resulting in rough and dry face. Therefore, in portrait photography, we should choose a lens with moderate sharpness instead of blindly pursuing high sharpness.

In addition, it is expensive to artificially increase sharpness through software. After excessive sharpening, most observers will see the separated boundary and feel a halo of light and dark around the line segment.

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