Luminanssiratio

Luminanssiratio, also known as luminance ratio, is a concept used in visual perception and display technology to describe the difference in brightness between the brightest and darkest areas of a scene or image. It is typically expressed as a dimensionless ratio, often on a logarithmic scale, because human vision responds logarithmically to light intensity. A high luminance ratio indicates a scene with a wide range of brightness, such as a sunny day with deep shadows. Conversely, a low luminance ratio signifies a scene with more uniform brightness, like a cloudy sky or an indoor setting with controlled lighting.

In photography and cinematography, controlling the luminance ratio is crucial for achieving a visually pleasing and technically accurate image. Cameras have a limited dynamic range, meaning they can only capture a certain range of brightness levels. If the luminance ratio of a scene exceeds the camera's dynamic range, either the brightest areas will appear overexposed (blown out) and detail will be lost, or the darkest areas will appear underexposed (crushed) and detail will be lost. Techniques like High Dynamic Range (HDR) imaging aim to capture and display scenes with much higher luminance ratios than traditional methods.

In display technology, such as televisions and monitors, the contrast ratio is closely related to the luminance ratio. It represents the difference between the brightest white and the darkest black a display can produce. A higher contrast ratio generally leads to a more vivid and detailed image, with deeper blacks and brighter whites. Understanding luminance ratio is fundamental for professionals and enthusiasts alike when evaluating image quality and optimizing visual experiences across different mediums.