To be able to reliably evaluate the colours of surfaces and materials, natural daylight is unsuitable. In the course of the day – and the year – it constantly changes its spectral configuration (and with that, the respective visual impression). Visual colour evaluation is indispensable when it comes to the selection and visual inspection of produced colours and materials. It is only after the visual determination of colour that colour measurements can take place and limit values can be defined.
But the evaluation of the colour sensation is not only important for a certain condition - metameric colours which appear identical under a certain type of light suddenly show stark contrasts when exposed to a different degree or type of light as the spectral configuration of the light sources and the evaluated materials is in fact different. According to the currently valid norms for visual colour evaluation, the colour samples must look identical when viewed under the light type D65 and can show certain discrepancies under other types of light– that is to say, Metamerism becomes visible. The JUST Normlicht standardized lighting devices give the viewer the chance to promptly recognize Metamerism in time.
JUST Normlicht technology achievements
For those who want to have a more complete control of the illumination and are looking for a future technology available today, JUST Normlicht already offers the technology of tomorrow by using LED lighting for colour evaluation.
To control the LED properties to the multiple requirements of JUST Normlicht, a complex multilevel calibration procedure was developed that calibrates each single LED light source and stores the spectral properties in the unit’s electronic controls. This process is unique and therefore has a patent filed for by JUST Normlicht. The multilevel calibration is divided into the basic factory calibration and permanent online-calibration during operation without using an external metrological device.
The JUST LED technology is not only exceeding the conventional Standardized Lighting Technology in light quality, but is now for the first time able to replicate a tremendous colour space with the highest quality, meaning a CRI between 90 and 100 and a Metamerism Index < 1. With this multispectral LED light source JUST Normlicht is creating a colour gamut larger than sRGB and is now able to replicate not only standardized light sources like D50 or D65 for the graphic arts industry but also other light sources like A, C, D55, D75 and any other white or coloured light. To avoid metameric failure caused by optical brightening agents, the UV-content in the light source is also included.
A second advantage of the JUST LED technology is a lifetime of at least 10 times longer than that of the traditional fluorescent lamp technique. This means not only stable, unchanging quality of light over a very long time period but also a high savings for replacement lamps over the life of a JUST LED Viewing Booth. Another advantage to keep in mind is the environmental benefit of the LED technology. By not using mercury and only a very little amount of phosphors, which are both major components of fluorescent lamps, the LED Technology reduces the amount of hazardous waste being disposed of in our landfills across the globe.
The cabinets are suitable for all industries and applications where there is a need to maintain colour consistency and product quality such as Textiles, Automotive, Ceramics, Cosmetics, Dyeing, Food, Footwear, Inks, Packaging and Printing.
In order to view your samples objectively without the influence of surround or background colours, the interiors of the cabinets are finished in a neutral matt grey.