Lamps

How many macho men does it take to change a light bulb? None. Macho men aren't afraid of the dark.

The colour qualities of a lamp are characterised by two different aspects - colour temperature and colour rendering.

Lamp Type	Approx. Colour Temperature	Colour Rendering (Ra)
Incandescent (240V)	2800 degree K	100
Incandescent 12V	Dichroic 3000 to 4000 degree K	100
Warm White Fluorescent	3300 degree K and below	50 to 90
Cool White Fluorescent	3500 to 4000 degree K	60 to 90
Daylight Fluorescent (Cold White)	6000 degree K and above	80 to 90

The colour rendering of fluorescent lamps in the table above varies from different manufacturers.

Application of Different Colour Temperature Lamps

	Use warm white for accentuating warm colours (red, brown cream etc.)
	Use cool white with cool colours like grey and blue
	Use daylight colours in hot climates as a warm lamp makes people feel hotter

Colour Rendering
Fluorescent lamps do not emit equal intensities over the colour spectrum, but have peaks and valleys across the visible spectrum. This causes unnatural appearance (rendering) of coloured objects when viewed under fluorescent lamps.

Colour rendering is the ability of a lamp to give good colour representation of the object it is illuminating. The unit of measurement is Ra.

Some lamps have better colour rendering than others and should be selected for colour critical applications.

Ra	Application
Above 90	Colour Matching, Picture Galleries
80 - 90	Homes, Restaurants, Textile Industry
60 - 80	Offices, Schools, Light Industry
40 - 60	Heavy Industry
20 - 40	Outdoor

International Colour Code for Fluorescent Lamps
The last three digits on many fluorescent lamps represents an international method of specifying a lamps colour rendering (Ra) and colour appearance (colour temperature).

	The first digit is the colour rendering decade. Eg: 9 = 90 to 99), (8 = 80 to 89)
	The second digit is the colour appearance x100. Eg: 30 = 3000 degree K

Triphosphor
Standard fluorescent lamps (halophosphor) have only one type of phosphor powder coating the inside of the tube. The purpose of this coating is to convert the ultra violet light that is produced inside the lamp by electric energy, into visible light. With only one type of coating the light produced will not have very good colour rendering properties.

Triphosphor fluorescent lamps have 3 different phosphors coating the inside of the lamp. Each phosphor operates in its own colour band (red, green & blue) to give an improved combined colour output.

Such lamps produce about 10% more light output and can be made with better colour rendering ability and higher temperatures (colour appearance) than lamps with one phosphor.