Why do some light fixtures use multiple bulbs?

Question

I've never really given much thought to this until recently. Why would I want to put multiple bulbs into a single fixture?

Every bulbs burns at a specific brightness. Putting more bulbs next to each other won't make the light brighter. Or will it?

So what does it actually do? Obviously, it will spread out light at a larger area, but how much are you actually achieving if the bulbs are so close together as they are with this fixture?

The question came up because I'm equipping multiple rooms with LIFX bulbs. When I spend that kind of money, I'd like to know that I'm actually achieving something by putting multiple bulbs right next to each other.

Answer 1

We use artificial light to light up things. The brightness of a thing depends on how many photons are falling on it. Doubling the number of bulbs actually does double the number of photons. That makes the thing visibly brighter.

One basic method of dimming a room is to have 2 switches, each of which controls some lights.

More bulbs will not throw the light any farther. What will happen, however, is that faraway things will get more light with more bulbs. For instance with a single bulb, it might get 5 lux... with 4 bulbs it will get 20 lux and thus be more visible.