Design Nomenclature / Light & Optics
High key
Also called high-key lighting
- Light & Optics
- Composition
- 2D & 3D
A tonal strategy placing most of a scene's values in the upper register with a low key-to-fill ratio, so shadows stay open and transitions gentle. The range is compressed toward the light end deliberately: it is a decision about where the histogram sits, not a failure of exposure.
In practice
Not the same as overexposed. High key with blown highlights is simply blown — the style depends on holding detail all the way to the top.
Not to be confused with
- Low keyA tonal strategy in which most of the frame sits in the lower register and a small, controlled area carries the light. The ratio is high, fill is minimal or absent, and form is described by the few edges that catch the key rather than by overall illumination.
- ExposureStrictly, the illuminance on the sensor multiplied by the time it is collected — lux-seconds, set by aperture and shutter alone. It determines how much light was actually recorded; ISO merely scales what gets done with the result afterwards.