Overexposure
An exposure that records more light than the sensor can hold, driving the brightest tones to pure white with no recoverable detail.
Measured in
stops (EV)
In depth
Once a photosite reaches full-well capacity it simply stops counting, and no amount of processing invents the missing information. Mild overexposure in raw is often beneficial because it lifts the shadows above the noise floor, but clipped highlights are permanent — which is why the histogram's right edge matters more than its left.
Examples in practice
A white wedding dress shot at +2 EV loses all lace texture; the same frame at +⅓ EV keeps every thread.