This section of the photo tricks from Radozhiva describes the main features of the AF-L / AE-L button.
Button AF-L / AE-L available on almost all modern digital SLR cameras, on Nikon cameras so for sure. I will give examples specifically for Nikon cameras, but the general principle is the same for almost all cameras.
Button AF-L / AE-L stands for Auto Focus Lock / Auto Exposure Lock - auto focus lock / auto lock exposure... The whole point of the button is hidden in its name - the button is mainly designed to lock focus and exposureroughly speaking, the 'it freezes' or 'stops'froze exposure and focus position in a specific position.
Why is such a lock necessary? Very often, the work of the camera's automation cannot 'understand' the photographer's idea and the photographer must get out as best he can with the help of semi-automatic and manual settings. To facilitate the task in the settings and immediately get a good result, there is a quick transition from the automatic mode of the camera to the manual locked 'Lock' mode. Situations in which automatic metering exposure cannot give a good result, and there are many situations where autofocus can fail.
Button AF-L / AE-L basically configured for several modes of operation:
- Block. AE / AF - in this mode, pressing the button locks exposure and auto focus lock. While the button is pressed AF-L / AE-L auto focus and metering exposure unavailable. This mode is rarely used.
- Block. only ae - when the button is pressed, only measurement is blocked exposure, This is one of the most convenient methods for working with the button. This is a great way to compose frames with complex lighting.
- Block. AF only - Auto focus lock is performed, a convenient mode when you need to take a series of shots while focusing on the same stationary subject. In focus mode AF S the same thing happens - the camera stops focusing when the lens has correctly focused. True, in the mode Block. AF only You can lock the focus in any position. This function is convenient for reflowing the frame.
- Fix AE block - this mode is the same as Block. only ae with the difference that when you press the AE-L / AF-L button, the exposure is frozen until the AE-L / AF-L button is pressed again.
- AF ON - a number of Nikon cameras do not have an additional AF-ON button on the camera body, therefore, the button AF-L / AE-L can be programmed to work in AF-ON mode. When the AF-ON mode is on and the AE-L / AF-L button is pressed, focusing by the usual method is blocked by half-pressing the shutter button. This mode is convenient to use. to create a focus trap effect.
- Block. Fv Is a very useful setting that allows you to lock the flash output. FV stands for Flash value (flash power value). In this way, the flash output can be locked, but the flash will not send test impulses and immediately will give an impulse of the necessary power. Also, there is another very useful flash lock function. When the camera is set to Block. Fv for button AF-L / AE-L, then when you press the first time on AF-L / AE-L one will happen test pulse flash and the camera measures the desired flash output and will no longer give test pulses.
- Other features: depending on the camera, button AF-L / AE-L You can assign many other functions for working with the focusing system and the method of metering exposure. For example, you can make it so that when you click on the button AF-L / AE-L the camera will go into one of the metering methods: matrix, weighted average, spot. Also, in the view mode, some cameras use the button AF-L / AE-L for lock delete pictures. Button AF-L / AE-L on Nikon D800 can be programmed to the virtual horizon function in the viewfinder.
If you set the button to Block. Ae, then you can consider such examples:
Example 1: We photograph the object with a strong difference in brightness in the frame. On the one hand, the sun shines through the foliage, and the automatic exposure system tries to adjust to the huge amount of light, on the other hand, there is our object in the frame, which is in a strong shadow. If we took a picture in the automatic metering mode, then most likely we would get a dark silhouette of a squirrel. When using the button AF-L / AE-L you can point the camera at a tree trunk, click AF-L / AE-Lto camera measured exposure by shadows, transfer the camera to a squirrel and take a picture, in this case we do not care what happens to the foliage, our main object will be normally exposed.
As can be seen from the example above, we got fully exposed foliage, but the squirrel has good brightness. Of course, this is a primitive example, but in the life of a photographer there are a lot of difficult situations.
Example 2: shot in the temple, automatic exposure metering tried to adjust to the bright light of electric candles, but my idea to show the beauty of the frescoes completely failed. To avoid such a dark picture, it is enough to point the camera at the mural so that the light of candles does not get into the lens, the camera will calculate the exposure, press the button AF-L / AE-L, compose a picture with candles and press the shutter button. Of course, there are many other ways to achieve the correct result, for example, using exposure compensation.
Example 3: if you configure the button AF-L / AE-L focus lock, then this function is convenient to use for shooting a series with the same focus position. For example, I photographed a burning suitcase. The object was always at the same distance from me, therefore, you can press the button AF-L / AE-L and constantly take a suitcase, and then choose the best shot with fire.
A large number of examples can be invented, the main thing is to understand the principle of the exposure meter and focusing.
I often use the button AF-L / AE-L, In most cases, it serves to lock the flash power and fix the exposure lock. The main thing is not to forget that it was pressed AF-L / AE-L in AE hold mode. For all kinds of focus manipulations, I use a simple manual focus mode.
Button AF-L / AE-L You can customize to various useful functions and simplify the shooting process. I advise you to conduct your own experiments with the button AF-L / AE-L.
Help to the project. Thanks for attention. Arkady Shapoval.