High-sensitivity photos will have noise. When should I increase the sensitivity value?
Image noise is what we usually call noise in photography. It is a random change in brightness or color information in an image, usually a manifestation of electronic noise. It is generally produced by the sensors and circuits of scanners or digital cameras, and may also be produced by the inevitable shot noise of film grain or ideal photodetectors.
There are many reasons for noise, such as long time exposure, machine Body overheating, image compression, etc., sensitivity is also one of the factors that affect photo noise. The higher the sensitivity value, the more likely noise will appear in the photo. In the digital age, we adjust the sensitivity of digital cameras by adjusting the amplification of sensor signal processing. Due to the increase in amplification, the signal-to-noise ratio of the output signal is reduced. Of course, noise appears. More specific principles are here. Do not discuss.
We know that the exposure effect of a photo can be affected by changing the three elements of exposure, aperture, shutter and sensitivity. In addition to special creative needs, we generally hope that the photos we take can be correctly exposed , These three interact, and all three are numerically bounded, so we need to apply flexibly.
When we need to use a small aperture to shoot, to ensure accurate exposure , You need to give priority to slowing down the shutter speed, and finally consider increasing the sensitivity appropriately, if conditions permit, cooperate with a tripod to keep the camera stable, and when we need to use a high-speed shutter to shoot, we need to give priority to shooting with a large aperture, and finally consider appropriate Increase the sensitivity.
When we need to reduce the aperture and require a certain shutter speed when shooting, or the aperture value has been opened to the maximum, without a tripod, the shutter speed has been slow enough to ensure stable handheld shooting. We can only increase the sensitivity value of the camera. Considering that the current cameras have built-in noise reduction functions, the post software can also handle the noise appropriately. The post-processing space of RAW files is relatively large, so we can still use a certain range of high sensitivity Numerical values. Of course, if the recording requirements are greater than the image quality requirements, then higher sensitivity values can also be used.
Author:SINA,If you need to reprint,please indicate the source:http://www.todaycamera.com/camera-reviews/high-sensitivity-photos-will-have-noise-when-should-i-increase-the-sensitivity-value