Focus peaking, zebras and histogram on Android
A small, bright phone screen makes it easy to miss a blown-out sky or slightly soft focus. Three monitoring tools fix that by measuring the picture for you. Here's how to read each one and use them together.
Why your eyes are not enough
A phone screen is small, bright and often viewed outdoors in sun. It's easy to miss a blown-out sky, or a face that's just slightly soft. Dedicated cameras solve this with monitoring tools that measure the picture instead of leaving it to your eyes. Three matter most: the histogram, zebras and focus peaking.
Histogram: read the whole exposure at once
A histogram is a graph of how many pixels sit at each brightness, from black on the left to white on the right.
- Bunched against the right edge: highlights are clipping to pure white. Detail there is gone, even in RAW.
- Bunched against the left edge: shadows are crushed to black. Some of that can be lifted later, but it gets noisy.
- No "correct" shape: a snowy scene should sit to the right, a night street to the left. What matters is whether the edges are piling up.
A per-channel (RGB) histogram shows red, green and blue separately. That catches a problem the overall graph hides: a red sunset or a blue sky can clip in one colour channel while the overall brightness looks fine. The clipped channel loses its gradation and turns flat.
Zebras: see what's about to clip
Zebras draw diagonal stripes over the parts of the picture that are at, or very close to, maximum brightness. Where the histogram tells you that something is clipping, zebras show you where.
- Turn zebras on and point at your scene.
- If stripes cover something you care about, such as a sky, a white shirt or a face, lower the exposure until they shrink or disappear.
- Stripes on things that should be white, like the sun, a lamp or a specular glint, are normal. Leave them.
Zebras are especially useful for video, where you can't fix a clipped sky afterwards as easily as in a RAW photo.
Focus peaking: manual focus at a glance
Focus peaking outlines the sharpest edges in the picture with a bright colour, often red. As you turn manual focus, the outline moves through the scene: whatever is outlined is in focus.
- Set focus, then check the subject is outlined, not the background behind it.
- It works by detecting contrast, so it shows strongly on textured, high-contrast edges and weakly on smooth or dim surfaces. A face in low light may barely light up even when it's sharp.
- For landscapes and night skies, set focus towards infinity and check that distant edges are outlined.
New to manual focus and exposure? Start with manual camera settings explained.
Using them together
- Frame, then glance at the histogram for anything piling up at either edge.
- Turn on zebras and lower the exposure until the important highlights are clean.
- Focus by hand until peaking outlines your subject.
- Shoot, and check one frame at full size.
For starting settings per scene, see the pro mode cheat sheet. If you shoot RAW, zebras still matter: RAW recovers some highlight detail, but not a clipped sensor.
In One Camera
One Camera has all three. Focus peaking marks the sharp edges in red, zebras stripe the highlights about to clip, and a per-channel histogram sits in the corner of the viewfinder. They're in Settings, under Monitoring, and come with One Camera Pro, together with manual ISO, shutter speed, focus distance and white balance on real dials. You can also try zebras, peaking and the histogram on a photo in your browser on our home page.
Questions
What is focus peaking on a phone camera?
Focus peaking outlines the sharpest edges in the viewfinder with a bright colour, often red, so you can see what's in focus while focusing manually. It detects contrast, so it shows most clearly on textured edges.
What are zebras on a camera?
Zebras are diagonal stripes drawn over parts of the picture that are at or near maximum brightness. They show where highlights are about to clip, so you can lower the exposure before you lose detail.
How do I read a camera histogram?
Brightness runs from black on the left to white on the right. Pixels piled against the right edge mean clipped highlights, and against the left edge, crushed shadows. A per-channel histogram also shows when a single colour clips.
Which Android camera apps have focus peaking and zebras?
Several manual camera apps do. One Camera includes focus peaking, zebras and a per-channel histogram under Settings, Monitoring, with Pro.