F-number

F-number is a way to measure how much light goes through a camera lens. Think of it like a funnel. The bigger the funnel, the more water can flow through it. In the same way, the bigger the F-number, the more light can go through the lens.

But why is this important? Well, when you take a picture, you need light to hit the camera's sensor to create an image. If there isn't enough light, the image will be too dark. If there's too much light, the image will be too bright. That's where F-number comes in.

A lower F-number means the lens can let in more light. This is good when you're taking pictures in low light situations, like indoors or at night. But when you're in bright sunlight, too much light can make the picture look washed out. This is when you want a higher F-number, which allows less light in.

One way to remember this is to think of F-number as a fraction: the smaller the number, the bigger the aperture (the opening in the lens that lets in light). And the bigger the aperture, the more light gets in. So, a small F-number, like f/1.8, means a big aperture and more light. A big F-number, like f/22, means a small aperture and less light.

Overall, F-number helps photographers control the amount of light that enters the camera, which affects the exposure and overall look of the photo.