What do AE, AF, SAF, MAF and EV on digital cameras stand for?

AE, AF, SAF, MAF, EV on digital camera stand for:

1, exposure value (EV): the aperture value (f value) is matched with the shutter speed to represent the exposure value. ?

2.AE is the abbreviation of automatic exposure control device. AE lock is locked in a certain AE setting, which is used to manually control the exposure during automatic exposure to ensure the normal exposure of the subject. ?

There are several points to note when using AE lock: 1, and manual mode or AE lock cannot be used when taking selfies. 2. Do not adjust the aperture size after pressing AE lock. 3. When shooting with a flash, do not use (AE) lock. ?

3. Supplementary explanation

ISO sensitivity is an international unified index to measure the photosensitive speed standard of film used in traditional cameras, which reflects the photosensitive speed of film (actually, the photochemical reaction speed of silver and light). Traditional cameras can choose low-speed, medium-speed or high-speed films with different ISO sensitivities according to the specific conditions of shooting scenes.

For digital cameras, actually, film is not used, but the intensity of incident light is sensed by CCD or CMOS and related electronic circuits. In order to unify the measurement unit with the film used by traditional cameras, the concept of ISO sensitivity is introduced. Similarly, the ISO sensitivity of a digital camera also reflects its exposure speed.

When the ISO value increases by 1 times, the photosensitive speed also increases by 1 times. For example, the sensitivity of ISO200 is 1 times higher than ISO 100, ISO 100 is 1 times higher than ISO200, 4 times higher than ISO 100, and so on.

The ISO sensitivity means that if you choose a higher ISO sensitivity under the same EV exposure value, you can get the same exposure with a faster shutter speed under the same aperture. On the contrary, a smaller aperture can be used to maintain correct exposure without changing the shutter. Therefore, when shooting in dim light, you can often choose a higher ISO sensitivity. Of course, for SLR cameras, you can also choose to use a larger caliber lens to improve the luminous flux. For ordinary digital cameras, because they use a fixed lens, only by improving the ISO sensitivity can they adapt to shooting in dim light, especially when auxiliary light cannot be used.

The film used in traditional cameras is improved by different production processes. Because there is no relevant information, it is estimated that digital cameras can improve the sensitivity by increasing the amplification gain. Due to the inevitable electronic thermal motion of electronic devices, noise will inevitably be generated, and the greater the gain, the greater the noise, which will produce more noise and noise on the image. In order to overcome this problem, some digital cameras adopt noise reduction function to minimize its influence. But it can only achieve good results within a certain range.

The Minolta D7 and Canon G 1 I have used have no noise reduction function, and the images taken with ISO sensitivity increased to 200 are unbearable. Even if ISO sensitivity is increased to 800, Canon D60 is cleaner than the former. However, if it is raised to ISO 1000 and exposed for a long time, you can still see a lot of noise and noise. Therefore, the noise reduction function can only work within a certain range.

Therefore, in the case of poor lighting conditions, we should first consider the application of auxiliary light (flash and reflector), then consider the use of tripod when auxiliary light cannot be used, and finally consider the method of improving ISO sensitivity.

For places with dark light, such as the shooting stage, you are not allowed to use flash or tripod. You can try to choose a digital camera with large lens diameter and noise reduction function, and a SLR digital camera can choose to shoot with a large lens.

Night shooting often uses a smaller aperture and a longer exposure time. If you choose a higher ISO sensitivity, it will inevitably produce noise and noise. At this time, a tripod can be used, and cable release may be used again. By choosing a lower ISO sensitivity, noise and noise can be avoided.

The performance of various digital cameras is different under different ISO sensitivities, so it is necessary to test them, even if they are improved, they should be controlled within a tolerable range. Because, although it can be adjusted by software later, it will inevitably reduce the clarity of the image accordingly.

Therefore, when buying a digital camera, you need to consider choosing a camera with noise reduction function. The lens aperture is larger, which is more conducive to shooting in low light. Try to use flash and tripod when shooting, and try not to use one with higher ISO sensitivity. 、