Many modern cameras have built-in face detection and use it for autofocus. As soon as one or more faces are detected in the subject, the camera tries to focus on these faces, even if the person(s) are moving. This is, of course, very convenient in many situations. However, especially newcomers to photography are often not aware of the effects of this function.

Face detection as standard

Face detection is often activated by default, especially in entry-level cameras. The manufacturers assume that the target group for these cameras mainly takes pictures at family celebrations or similar occasions and that people are therefore the focus of interest. This is certainly not entirely wrong. Face recognition then ensures (to a certain extent) that the focus is really on people. However, this only really works reliably if there is only one person in the picture. If there are several people in the picture, the camera focuses on the person closest to the camera. This is probably correct in most cases. However, one must be aware of this fact. In fact, many inexperienced photographers believe that all people in the picture are always in focus, regardless of the distance from the camera. This is probably because many cameras frame all detected faces in the image. This is then easily interpreted as if all faces can be in focus at the same time.

My research unfortunately could not clarify beyond doubt whether there are cameras that are intelligent enough (I generally don’t consider cameras to be particularly intelligent …) to take into account the different distance of the people from the camera and then (at least in full auto mode!) to choose an appropriate f-stop that gives a sufficiently large depth of field. But one can hope. It should not be particularly difficult.

Pitfall

In my opinion, you should disable face detection when you are not photographing people. When face detection is activated, it always seems to have priority, regardless of the selected autofocus mode. The camera will then sometimes focus on a person in the background or at the edge of the frame, when you really wanted to take a picture of something completely different. This can be very frustrating if you didn’t notice this characteristic of the camera when you took the picture. Paradoxically, this problem increases as face detection algorithms get better. This is because they then recognize people who are only very small somewhere in the picture.

Of course, face detection only works in live view mode on SLR cameras. It seems that face detection works much better on bridge and mirrorless cameras than on SLRs.

Conclusion

For beginners in photography, face detection can be quite helpful. However, I can manage very well without it (although our cameras have the corresponding function). As is often the case, I like to decide for myself where the plane of focus should be in my photo.

What do you think? Please feel free to leave a comment. I’m looking forward to it.