Basics of Lighting
It is necessary to understand some basics of lighting, if you are interior or architect professional. If you are designing your own space without professional skills, this would be helpful. There is a separate field of lighting engineering for this, but they are not affordable in small projects.
Let’s start with some hard words used in packaging of lighting products.
Lumens: Lumens is the unit of light, which means the amount of light. If any bulb has label of 100 lumens/watt, that means, light output would be 100 x total watt of that bulb. It is not all the usable light, because some are wasted in other directions, reflected and diffused.
CCT/ Color temperature: It is the shade of the light. There are three range of color temperature.
CRI (Color rendering Index): This determines the quality of light source. The mixture of red, green and blue color makes perfect light. Any defect will result in to poor quality of color rendering. You can’t see all the colors in lower rendering light. Generally RA>80% is considered as good CRI.
How to use Lights
Kitchen requires 250 to 500 lux, while show room or shop requires 500-1000 lux. If you can’t measure lux, you can calculate approximate lux using some math.
Let’s take an example of one shop which is 200 Sq.feet(18.58 Sq.mt). To provide 1000 lux you have to calculate lumens.
Lumens =Lux X Sq.mt
Lumens = 1000 X 18.58 = 18580.
Now you can estimate the number of lights. If you take 20W(2000 lumens) Light, you have to install 9 pieces of light to make enough illumination. If you take 10W(1000 lumens), It will be 18 Lights.
Decorative lights also include multicolor lights, animation and disco lights. Recently SMD led flexible strips are more popular as decorative lights. It comes in many colors and animation.