What is LUMINANCE? (and Candela) | Optometrist Explains?

Luminance is how bright something looks to your eyes, kind of like how loud a sound is when you're near it.

Imagine you’re sitting in a dark room with just one flashlight. That flashlight has luminance, the brightness of its light. Now, if you turn on another flashlight next to it, both are brighter than before. That’s because each flashlight adds more light, making the whole room feel lighter and easier to see.

Think of candela as the “strength” of that flashlight, like how much power it has to push out its light. A bigger flashlight might have a higher candela value, meaning it shines brighter even from far away.

When you read a book in dim light, it’s hard to see the words because there isn’t enough luminance, like trying to hear someone whisper in a noisy room. But if you turn on a lamp, all of a sudden everything becomes clearer. That lamp increases the luminance, just like turning up the volume on music.

So, candela is like how loud your speaker is, and luminance is how clearly you can hear, or see! Luminance is how bright something looks to your eyes, kind of like how loud a sound is when you're near it.

Imagine you’re sitting in a dark room with just one flashlight. That flashlight has luminance, the brightness of its light. Now, if you turn on another flashlight next to it, both are brighter than before. That’s because each flashlight adds more light, making the whole room feel lighter and easier to see.

Think of candela as the “strength” of that flashlight, like how much power it has to push out its light. A bigger flashlight might have a higher candela value, meaning it shines brighter even from far away.