Clipping

Clipping is what happens when a tone is brighter or darker than the file can record. The camera or editor stores it as pure white or pure black, and any texture in that area is lost. Highlight clipping shows as blown-out skies, windows, or skin. Shadow clipping shows as solid black with no visible detail. It can happen at capture or later in editing.

Both are clipping, at opposite ends of the tonal range. Blown highlights are areas that hit pure white, like a cloud with no texture or a window that reads as a white shape. Crushed shadows, also called blocked shadows, are areas that hit pure black, like a dark coat with no folds. Blown highlights are harder to fix, because digital sensors keep more usable data in dark tones than in bright ones.

A histogram maps tones from black on the left to white on the right. When highlights clip, the graph piles up in a tall spike pressed against the right edge. When shadows clip, the spike sits against the left edge. A histogram that ends before either edge means nothing has clipped. Most cameras can show the histogram in playback, and many show it live while composing.

Sometimes, if the file is RAW and the clipping is mild. RAW files hold extra highlight data beyond what the camera preview shows, so pulling the Highlights or Whites slider down can bring back some texture. When all three color channels have hit their maximum, the data is gone and no slider can rebuild it. JPEG files clip sooner and recover less.

A digital sensor records light in a linear way, and the brightest stop of the range uses half of all the available values. Once a pixel reaches its maximum, it cannot count any higher, so bright tones hit a hard wall. Dark tones fade into noise instead of stopping at a wall, which is why shadows can often be lifted in editing while blown highlights stay white.

A digital photo stores red, green, and blue values for each pixel. One channel can reach its maximum while the other two stay in range. The pixel does not turn white, but the color goes flat and loses texture, which is common in red flowers, sunsets, and neon signs. Editors show per-channel clipping as colored patches in the clipping overlay, and the RGB histogram shows one channel spiking at the edge.

No. Small specular highlights, such as glints on water or chrome, are meant to be pure white. Silhouettes rely on crushed shadows, and low-key portraits use a black background on purpose. High-key photos often let the background go to white. Clipping is a problem only when it removes detail the viewer expects to see, such as a face, a cloud, or the texture of a white shirt.

Zebra stripes are a live overlay on the camera screen or electronic viewfinder that marks areas above a brightness threshold. With the threshold set near 100 percent, the stripes appear only where highlights are about to clip. The photographer can then lower the exposure before taking the shot. Some cameras offer a blinking highlight alert in playback that does the same job after the fact.

RAW does not prevent clipping, but it raises the ceiling. The camera preview and the JPEG are built from a processed version of the data, and the RAW file keeps highlight information above that point. Mild clipping seen on the camera screen often recovers on the computer. Severe overexposure still clips in RAW, so exposing for the highlights matters even when shooting RAW.

Any adjustment that stretches tones can push them past the edge. Raising contrast, exposure, whites, or saturation can send highlights to pure white or one color channel to its maximum. Lowering blacks or adding a strong curve can crush shadows. Editors warn with a clipping overlay or a spike on the histogram. Holding Alt or Option while dragging the Whites or Blacks slider in Lightroom shows exactly which pixels are clipping.