Small apertures are good for landscapes and very well-lit scenes. At f/11 and higher, you’ll get a wide depth of field, with almost everything in your frame in focus. If you have a variety of subjects at different distances from you, dial up your aperture to ensure nothing is left out. “Product photographers also use higher f-stops because when you shoot products, it’s important for everything to be in focus,” says Morrison.
Pick your aperture with the exposure triangle in mind.
Aperture scales are handy to use as a quick reference, but they’re not the final say in how you should pick your f-stop. The truth is, there’s no single f-stop you should shoot with for any given scene. It’s a balance between your shutter speed, ISO and aperture and it comes down to how you want the photo to look.
If you’re shooting an indoor event with low light, you might want to stop down your aperture. But you also might not want a shallow depth of field. To keep everything in focus, you could shoot with a flash and keep your aperture in a medium range or crank up your ISO to compensate for the low light. You could also slow down your shutter speed to let in more light.
With all of these settings, you have many options when it comes to setting up a shot. It’s a bit like solving a puzzle with different variables and learning how to work with light takes a lot of trial and error.
Adjust the f-stop in your camera settings.
Film cameras and even some digital cameras use an aperture ring on the lens itself that you rotate to set the aperture size. But most DSLRs adjust aperture via a dial or touch screen selection. And while most film cameras can be adjusted by full stops only, most DSLR brands today allow you to choose from a wider range of increments.