Overexposed highlights lose all detail and texture on sensor or film — pure white, no recovery. Happens fast in HDR or direct backlight situations.
As soon as your sensor or film loses detail in the brightest areas, we speak of baked out areas. It sounds dramatic, but it's completely normal in everyday set life — if you're not careful. The sensor or emulsion simply can no longer distinguish between individual brightness levels; everything becomes a featureless white area. No structure, no color tone, no hope of rescue in the edit.
The physical limit lies at the maximum saturation of the sensor or the film layer, respectively. Photosites on the chip fill up until no more electrons fit — the signal clips. With film material (especially negative), the emulsion becomes so densely exposed at a certain light value that the chemical information literally collapses. In a digital workflow — especially with 8-bit material or streaming — this happens even faster because the tonal range reserves are smaller anyway.
Practically on set, you only notice the problem on the monitor or during review on the big screen. An overexposed skin area, a window with extreme backlight, a specular highlight — suddenly there's nothing left to salvage. Some colleagues accept this deliberately; others work against it with ND filters or flags. The trick: You need to keep an eye on critical areas already during exposure metering and camera setup. Histogram control is not a mere decoration, but craftsmanship. Especially with HDR productions or when you're battling very bright ambient light or sunlight, baked out areas become a constant adversary.
In the edit itself, you cannot restore baked out areas. No LUT, no curves, no colorist can conjure information out of nothing. At best, you can conceal it with blur, vignetting, or post-processing — but honestly? It's better to avoid it during shooting. Therefore: Plan your lighting precisely, know your sensor characteristics, and when in doubt, it's better to stop down one stop than to trust the clipping.