Traditional Culture Encyclopedia - Photography major - What is sharpness?

What is sharpness?

Question 1: What does sharpness mean? Sharpness is an index that reflects the sharpness of image plane and edge.

Introduction to sharpness:

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.

Definition of photography field:

In the field of photography, sharpness is used to represent the contrast of image edges. A clearer definition is that sharpness is the derivative amplitude of brightness with respect to space. Due to the characteristics of human visual system, high-definition images look clearer, but in fact, the increase in sharpness does not improve the real resolution.

Question 2: What does high edge contrast+sharpness of high and low frequency resolution mean?

There is no advantage. Now it is all computer software design, and the lens style of Canon Nikon is the same.

In the past, there was a saying that "Nikon is hard and Canon is soft", saying that Nikon lens has large contrast, high sharpness, while Canon has small contrast and poor sharpness, and it was even passed down as "Nikon Sharp Canon Meat". It's just a rumor. When Xinhua News Agency and major newspapers were buying Nikon equipment in the manual era, photographers flocked to praise Nikon for belittling other brands. This trend has not even changed with the collective replacement of Canon equipment by major news agencies. In fact, Canon's lens is not worse than Nikon's. Among the top 19 lenses evaluated by Hasselblad Lab, Canon was shortlisted for 3 shots and Nikon was shortlisted for none.

There is also a saying that Nikon is "stupid and sharp", paying too much attention to contrast (suitable for the rough newspaper printing in the past), losing the level details and being dry and blunt. This statement can't stand scrutiny, because Nikon lenses are not only used by newspaper reporters, but also popular in the high-end printed matter market.

The reason for the above statement is that in the past, the level of lens design was not high, and it was thought that the Japanese could not make a lens that could take care of all aspects like the Germans, so they could only take care of one thing and lose another. Nikon sacrificed levels and details for comparison; Canon lost its hierarchical contrast. But unless you buy old lenses, this statement is meaningless. The final shooting effect of modern lens is more and more similar. From the results, you can't tell Nikon's sharpness and dryness from Canon's meat and embellishment.

Question 3: What is the sharpness of the photo? It should be the definition of photos, that is, the definition of clear photos is for digital picture files obtained by digital cameras. Photo sharpness is an index of image plane sharpness and edge sharpness. The higher the definition, the higher the detail contrast on the image plane, and the clearer it looks. The main picture of a photo with good sharpness is clear; The definition is relatively blurred.

Question 4: What is full-open sharpness? Generally, when the lens aperture is fully opened (maximum aperture), the quality of the photos taken is not good and the sharpness is not high. The jargon is "a little fleshy", and the sharpness of the photo obtained when the aperture is fully open is the full-open sharpness.

Question 5: What is the definition of the TV? Clarity/clarity

Question 6: What does sharpness mean in a camera? Is the edge of the picture clear or blurred?

The higher the sharpness, the clearer the edge, and the more obvious the boundary between the subject and the background of the picture, which improves the definition, but the subject image is pasted.

The sharpness is reduced, the edges are blurred, and the clarity of the picture is reduced, but the layering with the background is strengthened, and it looks seamless.

For information about TV camera gaze, please refer to my whiteness space.

Question 7: How to control the sharpness when taking pictures? What do you mean too sharp? Before taking photos, you can set the sharpness in the camera menu. Post-sharpening can be done by software after shooting. Some people say that the photos you took were too sharp, which should mean that you were too sharp when you adjusted the photos later.

Question 8: What is sharpness? Why do you want to reduce the aperture in order to ensure the image quality? Sharpness refers to the sharpness of the scene in a photo (the sharpness of lines), which can generally be seen through the edge lines of the scene. Image quality is the carrier of sharpness. Narrowing the aperture to ensure the image quality is because a large aperture will affect the depth of field and the level of detail. Just like people's eyes, you can see more clearly when you reduce the aperture, but when you open your eyes (equivalent to increasing the aperture), the scenery is not as clear as when you reduce it. Therefore, narrowing the aperture will improve the image quality, including photo clarity.

Question 9: What is the sharpness of imaging? The most common field is sharpness ~

For example, a high-definition lens can see the hair clearly one by one ~

If the sharpness is low, it may be a group or a few mixed together ~

Question 10: What is the sharpness in photography? What is saturation? What do you have? What does it have to do with color? acutance

Sometimes called "sharpness", it is an index reflecting the sharpness of image plane and edge.

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 vividly displayed. 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.

Saturation capacity

Concentration of color intensity

Two color indicators