Interpretation of sensitive terms

Sensitivity is a measure of the sensitivity of a negative to light.

Sensitivity, also known as ISO value, is a measure of the sensitivity of negative film to light, which is determined by the measurement of sensitivity and several values, and has recently been standardized by the International Organization for Standardization. For the negative with low sensitivity, it takes a long exposure time to achieve the same imaging effect as the negative with high sensitivity, so it is usually called slow negative.

Highly sensitive negatives are therefore called fast negatives. Whether it is digital or negative photography, in order to reduce the exposure time, relatively high sensitivity usually leads to the decline of image quality, due to coarse negative particles or high image noise or other factors.

Color temperature: It is a unit of measurement, indicating the color components contained in light. Theoretically, blackbody temperature refers to the color of an absolute blackbody heated from absolute zero. After heating, the black body gradually changes from black to red, yellow and white, and finally emits blue light.

When heated to a certain temperature, the spectral component of the light emitted by the blackbody is called the color temperature at that temperature, and the unit of measurement is K. If the light emitted by the light source contains the same spectral component as the light emitted by the blackbody at a certain temperature, it is called a certain K color temperature.

Depth of field: refers to the range of the distance between the front and back of the object measured by imaging in front of the camera lens or other imagers. The distance from the aperture, lens and focal plane to the subject is an important factor affecting the depth of field. After focusing, the distance between the clear images before and after focusing is called depth of field.

White balance:

Literally means white balance. White balance is an index to describe the white accuracy of the mixed red, green and blue primary colors in the display. White balance is a very important concept in the field of TV camera shooting, through which a series of problems such as color restoration and tone processing can be solved.

Aperture: a device used to control the amount of light entering the photosensitive surface of the fuselage through the lens. Usually in the camera. For the manufactured lens, we can't change the diameter of the lens at will, but we can control the luminous flux of the lens by adding a polygon or circular aperture diaphragm with variable area inside the lens. This device is called an aperture.

In order to express the aperture size, we use the f number to express it, which is written as f, and the aperture is different from the f number. On the contrary, the size of the aperture is inversely proportional to the size of the f number, which is also called the aperture number. For example, a lens with a large aperture has a small f number and a small aperture number. A lens with a small aperture has a large f number.