LAMP OPTIONS etc.
With today’s complex colour requirements, a shade cannot always be assessed under one light source. Several may be needed so that the shade is viewed in applicable conditions, i.e. ‘Artificial Daylight’ and ‘Point of Sale’ Light.
This allows inconsistencies such as metamerism to be detected. When two coloured materials have identical spectral reflection curves, they will match visually under any illuminant. However, it is possible for two materials to match visually under one illuminant but mis-match under another, such matches are termed ‘metameric’.
How often have we heard the dissatisfied phrase, “The colour looked totally different in the shop!”. Well, that’s metamerism in action. Metamerism is the term used when two materials match visually under one light source but mismatch under a different light source.
This is usually a result of the colouring matter used in each material being different. With these factors influencing colour appearance it is important to standardise viewing conditions, especially for commercial use.
Please note individual retailers have differing specifications for the lamps and paint used in the Colour Assessment Cabinets, please check before ordering .
VeriVide equipment provides these conditions for all applications. For consistency, the source of light must be controllable and constant. To understand light sources, two factors need to be taken into consideration:
1. COLOUR TEMPERATURE – expressed in Kelvin. (K)
Colour temperature describes the colour appearance of the lamp itself and the light it emits and can vary along with its spectral power distribution. “Correlated” colour temperature applies to fluorescent lamps and approximates the true colour temperature.
Lamps with lower colour temperatures appear warmer i.e. red/orange and typical examples would be illuminant A and 830.
By comparison, lamps with a higher colour temperature look bluer, and examples would include the VeriVide D65 and D75.
2. COLOUR RENDERING INDEX (CRI)
A numerical system that measures how well colours are rendered by a lamp in comparison to a reference light source. The CRI is measured on an index from 0-100, with 100 representing an exact match, whilst low values indicate poor colour rendering.
Hence a lamp rated with a CRI of 98 such as the VeriVide D65 will show colours more accurately than a lamp with a CRI rating of 62 such as the CWF.
This rating method is recognised by the Illuminating Engineering Society (IES) and the Commission International de L’Eclairage (CIE).
Our full list of available lamp options are detailed below.
CIE Daylight Illuminants
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CIE Illuminant ‘A’
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Alternative (fluorescent) lighting / Point of Sale
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Horizon
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Ultra Violet