Who said what the camera's tolerance is?

1. The latitude (dynamic range) of a digital camera refers to the range between the maximum light intensity and the minimum light intensity that an image sensor can record, that is, the ability to record gray levels from white to black. Tolerance is one of the three most important imaging indicators of the sensor, and the other two are color depth and available high sensitivity.

2. The dynamic range is generally expressed by the number of gears in exposure value, and the unit is Evs. If the ratio of the maximum and minimum light intensities is 1024: 1, the dynamic range is 10 step aperture (1024 equals to the power of 2 10), which is expressed as 10ev. At present, the mainstream high-tolerance sensor cameras include Nikon SLR D8 10( 14.8Evs) and Sony micro-camera A7( 14.2Evs). Generally, the sensors with tolerance are around 1 1ev;

3. Because the minimum light intensity that the camera can record is related to the noise of the image sensor, the dynamic range is also a function of ISO value. The higher the ISO value, the more serious the noise and the lower the dynamic range. Some digital cameras extend the ISO value at the low or high end of the ISO value. These extended ISO values can reduce noise, but also reduce the dynamic range, which will not be described in detail here.

4. Generally speaking, the higher the tolerance of the sensor, the wider the area from white to black recorded by the camera, and the less likely it is to lose the image details of the brightest or darkest part; On the contrary, the imaging details are more likely to be lost, which means that highlights are more likely to die white and dark parts are more likely to die black. Therefore, the higher the tolerance, the stronger the imaging ability of the sensor;

5. Because the imaging ability of the sensor is restricted by many technical factors, such as A/D technology (analog-to-digital conversion technology) and SNR technology (signal-to-noise ratio technology), tolerance, color depth and available high sensitivity are all technical indicators that affect the imaging of the sensor, and various technical indicators of the sensor interact and restrict each other. If only the tolerance is high and other indicators are not good enough, the imaging quality is still not good enough. For example, the dynamic range that the sensor can capture is related to the camera's ability to convert optical signals into digital signals and store them (A/D technology). This ability is determined by the A/D conversion factor (called bit depth) in digital technology. The higher the bit depth of the recording medium, the larger the dynamic range that can be maintained. If the tolerance is only high and the A/D bit depth is not enough, the tolerance that the sensor can keep is still not high enough.

6. At present, most of the RAW files of SLR cameras can record the bit depth of 10 to 14 (JPG is 8 bits deep), so the theoretical dynamic range recording capacity is 10 to 14Evs. Therefore, the imaging quality of 14 file tolerance is better. If 14 is not reached,