What is Diopter?
What is Magnification Power?
What is Colour Temperature (Degrees Kelvin °K)?
What is Colour Rendering Index (CRI)?
What are Lumens?

What is Diopter?

Diopter refers to the curvature of a magnifying lens. As the diopter increases, the lens becomes thicker and the curvature greater. As the curvature increases, light rays are redirected to fill a greater portion of the viewer's retina which makes the object look bigger.

What is Magnification Power?

Power refers to how much larger an object looks through a magnifying lens. Power is typically indicated by an "X" such as 2X (2 times) or 4X (4 times). The common formula to convert the diopter of a lens into its Magnification Power is to divide the diopter number by 4 and add 1.

Common diopter/power relationships

What is Colour Temperature (Degrees Kelvin °K)?

Colour Temperature refers to the colour variation of light (the colour of the light) and is measured in degrees Kelvin. This scale ranges from the flame from a candle at around 2,000°K to deep blue sky at around 10,000°K.

In simple terms the colour a bulb emits is red at low temperatures and blue at high temperatures and white in the middle.

For a bulb or tube to be classified as "daylight" it will have a colour temperature of between 4,000°K and 7,000°K.

It is commonly accepted that a colour temp of 6,300°K to 6,500°K gives the closest reproduction of natural sunlight.

A standard tungsten bulb is around 2,700°K.

What is Colour Rendering Index (CRI)?

This is how colours appear under a light source. Natural sunlight has a CRI of 100, this displays all colours perfectly. An artificial light source with a CRI of 85 or over is comparable to natural light and will show the majority of colours in their true light.

What are Lumens?

Lumens are the measurement of the brightness of a bulb or tube. The higher the number of lumens the brighter the light output. The amount of lumens emitted is determined by the wattage of the bulb and the lighting technology.

The light from an incandescent bulb is produced by an electrical charge in the metal filament inside the bulb. This produces both light and heat.

Fluorescent bulbs and tubes are more efficient as their light source does not rely on the heating of a filament. Therefore these bulbs are both low heat and low energy. The light from a fluorescent bulb or tube is produced from a series of reactions between different elements, primarily phosphor.

Task lighting is essential when working in close proximity to your work piece, whether you are a crafter, model maker, dentist, collector or desk worker.

Task lighting provides focused light source just where you need it. This not only saves money on over powered lights but prevents unwanted shadows which hinders the working area.

A work space should include general background lighting and task lighting and if you work with small items a magnifier. The magnifier can illuminated or a stand alone magnifier.

The general background lighting can be provided by many different light sources and does not need to be expensive. But it is best to make this as close to natural daylight as possible as this helps with detail clarity, colour recognition and eye strain.

The task lighting should not be over bright as this will cause glare and eyestrain. Task lighting should be positioned to provide shadow free light to the work area. The task light should be as close to natural daylight as possible as this will give better detail clarity, colour recognition and reduce eyestrain.

The magnifier you choose will depend on the work area and the type of work you do. A separate stand alone magnifier gives flexibility of the positioning of the task light and the magnifier but can cause shadows when using the magnifier. A lighted magnifier will eliminate shadows. The illuminated magnifier can also be used as your task lighting.

There are many different sizes and styles of craft lamps, task lamps, magnifiers and magnifying lamps from desk top models to floorstanding lamps, wall mounted and desk mounted. As a lot of people, especially crafters work in their home environment the choice of their craft lamp will be based in some part by the styling of the lamp as well as the functionality of the light.

Think carefully about your work area and the requirements of the lighting before you make your choice as the right lighting and magnfication set up will greatly enhance your working experience.