How To Fix Common Autofocus Problems

Autofocus problems are usually solvable in under a minute once you know which problem you are looking at, and almost never solvable by buying a new camera. The pattern is the same every time: identify whether the camera is failing to find focus, finding it on the wrong thing, or finding it and then drifting off, and apply the matching fix. This guide walks through the eight most common autofocus failures, what causes each one, and the specific change in technique or settings that fixes it.

Before you start fixing things, make sure the equipment itself is healthy. Clean the rear contacts on the lens with a dry microfiber cloth. Make sure the firmware on both body and lens is current. Power cycle the camera. About one in ten reported autofocus problems is just a dirty contact or a stale firmware bug that the manufacturer already patched. After those baseline checks, the issues below are the ones you actually have to solve with technique.

Problem 1: The Camera Hunts And Will Not Lock

Symptom: you half press the shutter, the lens racks back and forth between minimum and maximum focus distance, and never settles on the subject. Cause: not enough contrast or light for the autofocus sensor to find an edge. Most autofocus systems need a vertical or horizontal edge of contrast to lock onto.

Fixes, in order of speed: aim the focus point at an edge of contrast (the eyebrow instead of the cheek, the lapel instead of the white shirt), turn on the AF assist lamp or use the focus assist light from a flash, switch to a single center focus point which is almost always the most sensitive point on the body, and as a last resort switch to manual focus and use focus peaking or a magnified live view.

Problem 2: The Camera Locks On The Wrong Thing

Symptom: you take a portrait, you get a sharp photo of the subject’s left ear or the foliage behind their head, and the eyes are soft. Cause: the AF area mode is too wide and the camera is picking whatever has the most contrast in that area, not what you want.

Fix: switch out of any “auto-area” or “wide-area” mode and use a single small focus point that you place on the subject’s near eye. On any modern body, enable eye detection AF for portraits. If you are working too fast to move the focus point manually, use a touch-screen tap or a dedicated AF joystick to position it. The whole point is to take the decision away from the camera and make it yourself.

Problem 3: Focus Is Slightly Off On Every Frame With One Lens

Symptom: every shot with a specific lens is consistently focused slightly in front of or slightly behind the subject. Other lenses on the same body are fine. Cause: lens-to-body calibration drift, a real issue on DSLRs that use phase detection autofocus through the mirror box.

Fix: use the camera’s autofocus fine-tune or autofocus micro-adjust function. Most DSLRs have it buried in the menu. The procedure: print or buy a focus calibration target, mount the camera on a tripod, shoot the target at the working distance for that lens at its widest aperture, look at where the sharpest plane actually fell, and dial in plus or minus calibration values until the sharpest plane lands on the target line. On mirrorless cameras this problem mostly does not exist because the AF sensor is on the imaging sensor itself, which is why the issue went away for most users when they switched systems.

Problem 4: Focus Drifts During A Burst

Symptom: in a burst of frames of a moving subject, the first few are sharp and the rest drift soft. Cause: you are using single-shot autofocus when you needed continuous autofocus.

Fix: switch to AI-Servo, AF-C, or whatever your camera calls continuous autofocus. Then check that your tracking sensitivity settings are appropriate for the subject. For erratic subjects (kids, dogs) raise sensitivity. For predictable subjects (a runner) lower it so the camera does not get distracted by passing obstacles. Combine with burst mode on the highest frame rate your buffer can sustain.

Problem 5: Focus Is Fine In The Center, Soft At The Edges

Symptom: when you focus and recompose, the subject ends up slightly soft. Cause: focus-and-recompose moves the camera through an arc, which slightly changes the distance to the subject. At wide apertures the depth of field is shallow enough that this small distance change is enough to push the subject out of the critical focus zone.

Fix: stop focusing and recomposing. Move the AF point to where the subject will be in the final frame, then take the shot without rotating the camera. Modern bodies have focus points spread across most of the frame; use them. If your AF system is heavily center-clustered, switch to back-button focus which makes it natural to focus once with the center point and then hold the camera steady while you wait for the moment.

Problem 6: Low-Light Autofocus Failure

Symptom: in dim rooms, the AF refuses to lock and you fall back on guessing. Cause: the AF sensor needs a certain minimum amount of light to work. Some cameras work down to -3 EV or even -6 EV, others need at least daylight.

Fix: in order, use a faster lens that lets more light to the AF sensor (f/1.4 or f/1.8 prime lenses help), enable AF assist lamp, point the center focus point at the highest-contrast edge available (a window edge, a bright reflection, the white of someone’s eye), and if all else fails use a flash with an AF assist beam that throws a pattern of red lines onto the subject for the sensor to lock onto. As a last resort, prefocus manually at the working distance and shoot using hyperfocal principles.

Problem 7: Autofocus Works Outside, Fails Indoors

Symptom: the camera focuses fine in daylight but struggles under domestic incandescent or LED light. Cause: artificial light is often a much narrower color spectrum than daylight, and some AF sensors have wavelength sensitivities that handle one better than the other. There is also less total light.

Fix: same approach as low light in general. Faster lens, AF assist beam, single center point, aim for contrast edges. On some bodies, switching from phase detection to contrast detection (Live View on a DSLR) actually works better indoors because contrast detection uses the imaging sensor which is more wavelength-tolerant.

Problem 8: Back-Focus Or Front-Focus Only At Wide Apertures

Symptom: at f/2.8 or wider the camera consistently focuses just in front of or behind the subject. Stop down to f/5.6 and the problem disappears.

Cause: shallow depth of field reveals tiny calibration issues that the wider depth of field at smaller apertures hides. Fix: same as Problem 3, use autofocus fine-tune. If the camera does not support fine-tune, send the lens and body to the manufacturer for calibration, or switch to eye detection or live view contrast detection focusing, which both use the imaging sensor and do not have the calibration issue.

Understanding How The AF System Decides

Knowing roughly how your autofocus system makes decisions makes troubleshooting faster. Phase detection AF (used on DSLR mirror boxes and on modern mirrorless sensors) compares two sub-images and measures how far apart they fall, which tells the camera which direction to move focus and by how much. It is fast but it depends on a clear comparison signal, which is why low contrast and low light hurt it. Contrast detection AF (used in Live View on DSLRs and on early mirrorless) racks focus back and forth and watches for the moment image contrast peaks. It is slower but more wavelength-tolerant and does not suffer from calibration drift. Most modern mirrorless bodies combine the two: phase detection finds the rough zone, contrast confirms the final position. This is why mirrorless AF is generally more accurate at wide apertures than the older DSLR-only phase detection systems were.

AF For Specific Subjects

Portraits Of People

Eye detection AF on, AF-C, single point as fallback. Place the AF point on the near eye. Trust the camera to track if you hold the back-button down through a burst.

Sports And Wildlife

AF-C with a small group of points (not a single point, which can lose subjects, not auto, which picks the wrong subject). High frame rate burst mode. Tracking sensitivity set to medium-high for erratic subjects like birds in flight. Pre-focus on the spot where action will happen, then track as the subject enters.

Landscapes

AF-S with a single center point placed about a third of the way into the scene, or use hyperfocal distance focusing manually. Stop down to f/8 or f/11 for full depth of field.

Macro And Close-Up

Manual focus is often more reliable than AF at very close distances because the depth of field is so thin. Use a tripod, magnify Live View, and dial focus manually. Or rack focus by gently rocking the camera back and forth and shoot a burst, picking the sharpest frame in post.

The Settings Checklist For Reliable Autofocus

• Single point or small group AF area mode, not wide-area auto.
• AF-C / AI-Servo / continuous for moving subjects, AF-S / one-shot for static.
• Back-button focus enabled, so shutter half-press does not refocus accidentally.
• Eye detection AF on for people and pets.
• AF tracking sensitivity adjusted to the subject’s behavior.
• Lens firmware current, contacts clean, body and lens calibrated if DSLR.
• AF assist lamp enabled, or external flash with AF assist on.

Common Mistakes

• Relying on wide-area auto AF for portraits. The camera will pick whatever has the most contrast, which is rarely the eye.
• Focus-and-recompose at f/1.4. The arc you sweep through is enough to lose critical focus.
• Using AF-S on moving subjects. The camera locks once and does not track. Use continuous.
• Blaming the camera before checking lens contacts, firmware, and calibration.
• Trying to focus on a flat featureless wall, then assuming the AF is broken. Give it an edge.
• Forgetting to switch back from manual focus after the last shoot. Half the “autofocus is broken” reports turn out to be the MF/AF switch on the lens being on M.
• Not using the AF joystick or touch screen to position the point. Moving the camera to put a center point on the subject and then recomposing is slower and less accurate than positioning the point.
• Setting AF tracking sensitivity to maximum for everything. For predictable subjects, a slower tracking sensitivity is more accurate.

Try This (10-Minute Drill)

Find a willing person and a textured background. Set your camera to AF-C with a single point and eye detection on. Have them walk slowly toward you from ten paces away. Shoot a burst of ten frames as they approach, holding focus on the near eye. Review the frames and count how many are critically sharp on the eye. If fewer than seven out of ten are sharp, your AF tracking is undertuned for moving subjects or your shutter speed is too low. Raise tracking sensitivity, raise shutter speed to at least 1/250, and try again. Repeat until you reliably get nine out of ten sharp. That is the level of trust you need in your autofocus before a paid shoot.

Frequently Asked Questions