Focus peaking is a manual focus aid that overlays colored highlights on the edges with the highest local contrast in the live view or electronic viewfinder, showing the photographer which parts of the scene currently lie in the plane of focus. In focus and autofocus within photography, it is the standard visual tool for judging sharpness without magnification when the lens is focused by hand.
Peaking does not move the lens or measure distance. It analyzes the live image that the sensor already produces and marks areas where fine detail is strongest, on the assumption that sharp areas contain the most high-frequency contrast. This makes it fast and intuitive, but also explains its main weakness: it reacts to contrast, not to true focus.
How focus peaking detects sharp edges
The camera processor runs an edge-detection filter on each frame of the live feed, typically a high-pass or gradient operator similar to the Sobel or Laplacian filters used in image processing. Pixels where brightness changes sharply from one neighbor to the next receive a high score, and pixels above a threshold are painted in a chosen color such as red, yellow, white or blue.
Because a defocused image loses its fine detail first, the number and intensity of highlighted edges peak when the subject is in focus. As the focus ring turns, the colored outline grows stronger on the subject, then fades as focus passes beyond it. The principle is the same one used by contrast detection AF, except that peaking leaves the decision to the photographer instead of driving the lens motor.
The display resolution matters. The live view feed is usually downscaled from the full sensor resolution, often to a few megapixels or less, so peaking evaluates a smaller image than the final file. Edges that look crisp at viewfinder resolution can still be slightly soft at 100 percent on a high-resolution sensor.
Peaking settings and what they change
Most cameras offer three adjustable parameters: peaking level, color and display mode. The level sets the detection threshold and has the greatest effect on accuracy.
| Setting | Typical options | Effect on use |
|---|---|---|
| Peaking level | Low, mid, high | Low marks only the sharpest edges, high marks more area |
| Peaking color | Red, yellow, white, blue | Choose a color absent from the scene |
| Display mode | Always on, MF only, during focus ring use | Reduces clutter when not focusing |
| Peaking with magnification | On or off during zoomed view | Combines overview with precise checking |
| Video output | Shown on camera, external monitor or both | Keeps recorded footage clean |
A low peaking level is the more precise choice because only the strongest edges cross the threshold, so the highlighted zone is narrower and closer to the true focus plane. A high level is useful for low-contrast subjects and dim light, but it marks a wider band of the scene and overstates the depth of acceptable sharpness.
Focus peaking compared with other focus aids
Focus peaking is one of several focus aids, and each serves a different purpose. The comparison below places it next to magnification, the electronic focus guide and the autofocus methods from the same topic.
| Method | How it works | Main strength | Main weakness |
|---|---|---|---|
| Focus peaking | Highlights high-contrast edges | Fast overview of the focus plane | Imprecise at high resolution |
| Focus magnification | Enlarges part of the live view | Highest precision | Loses the overall composition |
| Focus guide indicator | Uses phase-detection data to show direction | Shows which way to turn the ring | Limited to AF point areas |
| Contrast detection AF | Lens hunts for maximum contrast | Accurate and automatic | Slower, may hunt in low light |
| Phase detection AF | Measures defocus amount and direction | Fast tracking of moving subjects | Needs compatible lens and light |
In practice, experienced photographers combine peaking with magnification: peaking finds the approximate focus quickly, and a magnified view at 5x to 15x confirms the critical point, such as the nearest eye in a portrait.
Where focus peaking is most useful
Peaking is most valuable whenever manual focus is necessary or preferable. It became widespread with mirrorless cameras and is now standard in video cameras, where autofocus behavior can be unpredictable during a take.
| Situation | Why peaking helps | Recommended setting |
|---|---|---|
| Adapted manual lenses | No autofocus is available | Low level, high-contrast color |
| Video focus pulls | Shows focus shift live during recording | Mid level, external monitor |
| Macro photography | Very thin depth of field | Low level with magnification |
| Focus stacking | Shows each slice of sharpness | Low level, step through the subject |
| Landscape at hyperfocal distance | Shows the extent of the sharp zone | Mid level, check corners |
| Astrophotography | Stars confirm infinity focus | High level with magnification |
In focus stacking, peaking is particularly efficient because the highlighted band visibly moves through the subject with each focus step, making gaps between slices easy to spot before the sequence is captured.
Limitations and common mistakes
The central limitation is that peaking measures contrast, not focus. A strongly textured subject slightly out of focus can produce more highlights than a smooth subject that is perfectly sharp, so the overlay must be interpreted rather than trusted blindly.
| Symptom | Cause | Fix |
|---|---|---|
| Slightly soft images at full size | Level too high or low display resolution | Lower the level and confirm with magnification |
| Highlights on the background only | Background has more texture than subject | Judge the subject edges, not the strongest overlay |
| Overlay hard to see | Peaking color matches the scene | Switch to a contrasting color |
| No highlights in dim light | Noise and low contrast | Raise the level or brighten the live view |
| Peaking visible in footage | Overlay sent to the recorder output | Disable peaking on the clean output |
A further mistake is relying on peaking at very wide apertures on high-resolution sensors. At f/1.4 on a 40-60 megapixel body, the depth of field can be a few millimeters at portrait distance, and the peaking band is often wider than the actually sharp zone.
Understanding it simply
Focus peaking is like a highlighter pen for sharpness. While you turn the focus ring, the camera draws colored outlines on whatever is sharp. You can see at a glance where the focus lands.
It works by looking for crisp edges. Sharp things have crisp edges, and blurry things do not. That makes it quick and helpful. For the finest precision, though, it works best together with a zoomed-in view of the most important detail.
Applied in practice
A documentary videographer films an interview with a vintage 50 mm manual lens on a mirrorless camera. She sets peaking to a low level in red, sends a clean signal to the external recorder and keeps the overlay only on the camera screen.
Before recording, she magnifies the subject’s nearest eye at 10x to set exact focus at f/2, then returns to the normal view. When the speaker leans forward, the red outline on his face fades and reappears on the bookshelf behind him, which tells her to pull focus closer. The interview stays sharp throughout, and the recorded footage contains no overlay.