I took all of these photos of the lid of my MacBook Pro using a Canon EF100mm f/2.8L Macro IS USM lens on a rainy December 16, 2022 in New York City.

The focus distance is exactly the same among all of the photographs.

At what aperture can you start to make out the Apple logo? On my monitor, when my browser window is full-screen, I can start to see that the photograph is of the Apple logo at f/14. It's easier to see earlier in a smaller window.

What does "aperture" mean in photography?

The "aperture" of a lens is a variably-sized hole in the lens through which light travels. The lens' aperture exists between the photographic subject and the camera's sensor. If you have a DSLR or mirrorless camera, you can probably see your lens' aperture if you look into it while taking a photograph.

If the camera's aperture is larger, and the camera's shutter speed and ISO values stay the same:

• The camera's "f-number" is small, i.e. f/2.8.
• The plane of focus is smaller.
• More light will hit the camera's sensor.
• Usually, the camera lens will exhibit more vingetting (the darkening of the photo's corners).

If the camera's aperture is smaller, and the camera's shutter speed and ISO values stay the same:

• The camera's "f-number" is large, i.e. f/22.
• The plane of focus is larger.
• Less light will hit the camera's sensor.
• Usually, the camera lens will exhibit less vingetting (the darkening of the photo's corners).

You can see all of these effects while using the interactive tool above. Spot the significant vingetting in the corners at f/2.8!