How to choose a light bulb

An incandescent bulb

Now that we’ve made it through the shortest day of the year and the days are getting longer, I find myself yearning for the light of Spring. Things just seem easier when we are surrounded by light, so brightening up the dark days of winter is still very much on our minds. We depend on artificial light at this time of year, and the type of light we see can really affect our mood. So how do we get it right and make ourselves feel happy instead of glum? It’s all about the type of lighting we choose, and that starts with the humble light bulb.

There are a few things to consider when buying a light bulb - brightness or the amount of light it produces, shape, energy efficiency, and colour temperature. There are so many choices that it can be really confusing, so here’s my quick guide, starting with the types of bulbs available. 

The first commercially viable light bulb was created by Thomas Edison and is known as an incandescent bulb. These became the ones that we are all used to - the typical ‘bulb’ shape we all know and love. There weren’t many choices when it came to shape, style and colour. When we needed to replace one we used to just pop down to Woolworths and buy a 40 watt or 60 watt bulb (or a 100 watt bulb if we wanted the room to be scarily bright). Most light bulbs were clear, or if we wanted to be a bit fancy we would buy a frosted bulb. That was it - it was fairly simple and straightforward, but then the results we got were also simple and straightforward - a bright light with one colour and not many options to create a mood.

A halogen bulb

A twisted CFL bulb

A loop CFL bulb

An LED bulb with a tungsten look

So, where does that leave you if you need to buy a new light bulb? Chances are you’re probably going to buy an LED, because of their efficiency and the huge range of styles available. The next question is usually, how do I know how bright it will be? We all used to understand brightness in terms of wattage as there weren’t many options and you could easily see the differences between a 40 watt bulb compared to a 60 watt bulb.
When the various types of energy efficient bulbs came to the market, they continued to be sold by wattage, but these numbers were much smaller than we were used to. Wattage actually measures the amount of energy the bulb uses to produce the light, not how much light it gives off. So, when the packaging tells us that the bulb we’re trying to buy is an 11 watt one, that leaves us thinking ‘how much light will I get?’ and ‘what’s that in old wattage?’.

The answer is to look at the Lumens, which is a measure of brightness. The great thing about using Lumens to compare brightness is that it applies to all types of bulb, no matter what technology is inside the bulb. Once we know the amount of Lumens we need, it makes it all much simpler. Here’s a handy conversion chart, which I still find myself referring to:

Okay, so now we know which type of bulb to buy and how much light we need it to give us. The next thing to consider is the colour temperature. Think of the colour difference between bright morning light and a pinky sunset. The blue light of the morning sky will make us feel awake and energised, whilst the pinky soft glow of the sunset will make us feel relaxed. It’s the same with bulbs. Do you need a bright, cooler light for say over the bathroom sink (so you can see what you’re doing), or do you need a warmer, softer glow for the lamp in the living room? That’s the colour temperature.

An LED bulb giving off a cool or blue light

An LED bulb giving off a warm glow

There is one final thing to consider when buying bulbs, which touches on lighting design. The direction and spread of the light you get from your bulb will give you different effects which can be used around your home. The type of light fixture you use will generally determine how this happens, as some shades will concentrate the light in a particular direction, and others will help it to spread around the room. For example, a desk lamp will give you a smaller, more targeted light (perfect for working at a computer or reading with). A lampshade will give a wider spread of light coming from the top and bottom of the shade. The light will be softened or diffused by the fabric, making it perfect for use in the evening when you’re watching TV and want to relax.

A lamp with the lampshade diffusing the light for a soft glow

A task lamp where the shade directs the light to a narrow area

If you're anything like me you'll have a mixture of all sorts of bulbs in your home, some old, some new, and some of them not quite doing the job you want them to. But at least now when you need to replace one, you'll know where to start.