What does the l key of a SLR mean?

The L key means the lens lock key in SLR photography. When we need to use a long focal length lens for shooting, we may need to enlarge the aperture, and then we need to lock the lens on the camera. This can prevent the lens from moving accidentally when the camera is moving or shooting, and maintain the stability of the shooting effect.

The L key can also represent the "long exposure delay" function. This means that when a long exposure is required, by setting an extended exposure time, you can avoid photo blur caused by handheld photography or scene movement. This function is very suitable for night scene photography, star trail photography and other fields.

In addition, the L key is often used to select the focus point function and specify the location of the focus. This is useful for shooting scenes that require an obvious subject. By selecting the appropriate focus point, you can make the subject more prominent in the photo and achieve better shooting effects. This is also one of the advanced shooting functions provided by SLR cameras.