Each Wednesday we feature a specific wavelength of light and try to feature a user submitted application. This week I'm focusing on a slightly different take on "wavelength" by looking into the D65 white point as part of the CIE color standard. There are two big trade shows coming up over the next couple of weeks that we will be attending; Cinemacon and NAB Show. Both of these events depend on properties of light that are at the core of the photonics industry. The most common white point is "D65" and that's the focus of this week's Wavelength Wednesday!
D65 is a color standard set by the International Center for Illumination and is based on a sunlight illumination that equates to light produced at 6,500 Kelvin.
To be more specific "CIE standard illuminant D65 - This is intended to represent average daylight and has a correlated colour temperature of approximately 6 500 K. CIE standard illuminant D65 should be used in all colorimetric calculations requiring representative daylight, unless there are specific reasons for using a different illuminant. Variations in the relative spectral power distribution of daylight are known to occur, particularly in the ultraviolet spectral region, as a function of season, time of day, and geographic location. However, CIE standard illuminant D65 should be used pending the availability of additional information on these variations." Source
The reason movies, displays, projectors, and televisions use this standard is so that images produced across multiple desplay technologies look as similar as pssible. Additionally, when the same white point is used across multiple applications the reproduction of the original color spectrum is more consistenten. Different color standards cover different parts of the color gamut. With the same "starting point" of D65 White the relative color reproduction standards can be viewed and reproduced accurately. Rec 709, Rec 2020, and DCI P3 are several of the most common industry color standards and must all be calibrated based on the D65 White Point as shown in the image below.
Now for just a bit of shameless self promotion. Our Illumina Cinema Laser System and Illumina Light Farm are designed for projection applications and produce a wide spectrum of color with exactly a D65 white point! (Also, it covers DCI-P3, Rec. 709 and better than 95% of Rec 2020!)
WavelengthDaylight equivalent of 6500 Kelvin
Description of Laser Application
The Illumina is designed to replace xenon bulbs in cinema and other projection applications.
In their own words:
From 5,000 lumens to 250,000 lumens the Illumina Cinema Laser System and the Illumina Light Farm can provide 20.000k + hours of uninterrupted beautiful light!