As anyone who used an SLR 20 years ago knows, autofocus today does amazing things—from facial recognition and eye tracking to overall impressive speed and accuracy. Yet as amazing as autofocus may be, there are still times when it’s better, faster and more accurate to go manual. From tricky lighting scenarios to subject-specific technical challenges, here are six situations in which photographers should switch from autofocus to manual focus mode.
1. When Using a Tripod And Shooting A Still Subject
When the camera is on a tripod and the subject isn’t moving, this is the perfect situation to use manual focus. In fact, it’s all but necessary lest you risk the camera refocusing and accidentally choosing the wrong point of focus. Landscape photographers, for instance, may want to lock down their camera and manually focus to ensure a foreground tree or rock is in sharp focus rather than the wide-open background. Tabletop photographers most certainly lock their cameras to a tripod and manually focus, picking precisely the point that will provide sharpness exactly where they need it.
2. When Tolerances Are Tight And Precision Is Required
In certain circumstances, you need to focus on a very specific image element. This is made easier, of course, when the camera is on a tripod and the subject isn’t moving around, but it doesn’t have to be that same scenario. The effect is especially pronounced when working with a wide aperture that produces shallow depth of field because missing focus means an unusable frame. More often, though, such specific focus requirements come with depth of field—when the photographer is charged with ensuring the entirety of an object is in sharp focus front to back. Product photographers and tabletop shooters deal with this, for sure, but so do architectural photographers and landscape photographers who utilize the knowledge that depth of field falls one-third in front of the point of focus and two-thirds behind it. By keeping this in mind and focusing partway into the area that needs to be sharp, maximum depth of field can be applied where it’s needed—and it’s only repeatable with manual focus.
3. When Compositing Multiple Exposures
Speaking of repeatability, when shooting multiple frames for compositing together later in post—whether that’s for focus stacking, noise reduction or creative problem solving—autofocus is a big no-no. That’s because anything that changes the frame between shots can ruin the entire process and make compositing multiple exposures difficult or impossible. In these situations, photographers use cable releases or tethered capture to keep hands off the camera, and so if the camera were to refocus even slightly, the precise sharpness and depth of field could change and cause real issues depending on the nature of the composite. So the best approach when shooting to make a layered file is to switch to manual focus to ensure the shot’s sharp where you need it to be.
4. When The Subject Is Moving Too Fast For Autofocus
For many years, sports photographers swore by their ability to manually focus with more precision than early generations of autofocus could keep up—particularly when it comes to athletes running and jumping. And while autofocus has certainly come a long way, there are still situations—and still cameras—that make autofocusing with a fast-moving subject difficult or impossible. If you find you can’t keep up with a subject while set to autofocus, switch to manual and think ahead. Choose a point of focus where the subject will be in a moment’s time, and when they reach the prefocused position, fire away.
5. In Tricky Lighting Situations
This could be low light or a backlighting scenario—both of which can cause autofocus to hunt for focus and move right through the perfect point of focus. Sometimes it finds it, sometimes it doesn’t. Rather than waiting for the camera to stumble into sharpness, flip the switch to manual and nail the focus precisely as you like it. The human eye usually does much better in low light and backlight, so taking over with manual focus is usually a recipe for success when the ambient light makes autofocus difficult.
6. When You’re Shooting Through An Opening
Have you ever tried to photograph your kid’s baseball game by aiming your camera through a chain-link fence, only to find that the camera keeps trying to focus on the fence a few inches from the camera? This problem can be helped by ensuring your camera is as close to the fence as possible, but depending on the size of the opening it may not be enough. Since the action is likely to be at infinity—or at least fairly far from your lens—manual focusing becomes easier as big movements on the playing field don’t necessarily make for changes in focus. Similarly, if you’re shooting through any opening—an archway in Venice, for instance, or an open window to view the landscape beyond—the camera can easily be confused and try to focus on the framing device rather than the subject beyond. So in these situations, switch to manual focus and dial in the sharpness by hand.