What is Luminance Contrast

Luminance refers to a measurement that describes the perceived brightness of a color. It indicates how bright a color appears when reflected from a surface. Additionally, relative luminance is defined as the relative brightness of a specific point within a colorspace, with black normalized to 0% and white normalized to 100%.

The recommended luminance ratio between the working area and the walls is less than 5:1. However, recent studies indicate that the luminance ratio between the working area and the normal field of vision (ambient area = wall/ceiling surfaces) should be 2:1, with an illuminance of 500 lux in the working area.

Blue stars are typically the most luminous, while red stars are the least luminous. However, seasoned observers may come across red stars during nighttime that are brighter than white or blue stars.

Earlier, normal luminance for normal activities typically ranged from 100 to 300 lux. However, nowadays, the light level commonly falls within the range of 500 to 1000 lux, depending on the specific activity. In cases that require precision and detailed work, the light level may even reach as high as 1500 to 2000 lux.

SDR formats are capable of displaying a maximum luminance level of approximately 100 nits. However, in the case of HDR, this value significantly increases to a range of 1,000 to 10,000 nits. HDR technology allows for deeper black levels and more vibrant and saturated colors.

With regards to point luminance, there was an observed variation of approximately 3% for every 1m increase in distance from the measured point. However, the influence of distance on surface luminance was comparatively less significant than that of point luminance. These findings from the study suggest that luminance values do indeed fluctuate depending on the distance at which they are measured.