How to use A, Av, Tv and M files (Photography Technology Compilation)

After that, many friends expressed different views through comments, notes and messages, mainly because there were substantial differences between them. To this end. Today, I will describe the basic principles of A, Av, Tv and M files in digital camera shooting mode (because the principles of "P" program files and "A" automatic files are basically similar), which I believe will be helpful to all friends who have just dabbled in digital photography. "A" (automatic file, or "fully automatic file" or "stupid file") must be declared again. A, Av and TV files are set on the premise of obtaining accurate exposure, and have nothing to do with autofocus. When the shooting mode is set to "A", the camera metering mode is set according to the principle that shutter speed, aperture value and ISO sensitivity take precedence. That is to say, the principle of ensuring shutter speed is the first priority of all kinds of digital cameras (basic guarantee 1/60s or above); Secondly, on the basis of ensuring sufficient exposure, try to narrow the aperture of level 2 or above to get a clear picture; Thirdly, if you can't get enough exposure on the above basis, you can get appropriate exposure by improving ISO. Fourthly, if you still can't get enough exposure when increasing ISO to the local maximum, increase the aperture value of the camera lens to the maximum; Fifth, when the above still can't get enough exposure, start to reduce the shutter speed until you can get enough exposure. This is a combination program of shutter speed, aperture and ISO sensitivity in digital camera "A" (automatic conversion) mode. This mode is the first choice for photographers in good lighting conditions, and the success rate is also high. Av (Aperture Priority), Av- Aperture Priority and A- Auto are completely different modes. The "Av- Aperture Priority" file is based on the aperture value determined by the photographer in advance before shooting. In order to get enough exposure, the camera will automatically increase or decrease the shutter speed on the basis of setting the aperture value. Its biggest difference is that when the photographer can't get the appropriate exposure by increasing or decreasing the shutter speed, he can only get the appropriate exposure by adjusting the ISO sensitivity in manual mode. Because in this mode, the shutter speed and ISO sensitivity are not linked. This is one of the essential differences between semi-automatic mode and full-automatic mode in exposure combination program. This mode is more suitable for taking photos of flowers, people, landscapes, etc., to ensure that the photos taken have sufficient depth of field or good background blur effect. The mode of TV shutter priority and A automatic is the same as the mode of Av aperture priority. The "TV-Shutter Priority" file is based on the shutter speed value determined by the photographer in advance before shooting. In order to get enough exposure, the camera will automatically increase or decrease the aperture value according to the set shutter speed value to get the appropriate exposure. Its biggest difference is that when the appropriate exposure cannot be obtained by increasing or decreasing the aperture value, the photographer can only obtain the appropriate exposure by adjusting the ISO sensitivity in manual mode. Because in this mode, the opening or closing of the aperture has nothing to do with ISO sensitivity. This is the second essential difference between semi-automatic mode and full-automatic mode in exposure combination program. This mode is more suitable for taking dynamic photos of sports, stage performances, birds and animals. Ensure that the photos taken have sufficient clarity. "M" (full manual shift) "M" full manual shift I think everyone must understand it. That is to say, when we set the camera to "M" when shooting, the aperture, shutter speed and ISO sensitivity required for shooting at this time will be set by the photographer, and we will adjust the combination according to the shooting conditions on site, including fine-tuning exposure compensation. You will really enjoy shooting. This shooting mode needs to be honed by long-term shooting practice, and also needs the support of corresponding photographic theoretical knowledge. This mode can cope with almost any shooting conditions. The above is only for pure SLR digital cameras, because some stupid or semi-stupid digital cameras also have the "M" file function, but their actual operation mode is different from that of pure SLR, which basically belongs to a prosthetic leg-it's tedious to operate, but it's good to get used to it (see its manual for details). The above is purely a personal opinion, for your reference only!