Lava Light Lessons #6…How a Camera Captures Light…and How You Control that Capture…part two: Aperture

Aperture is the second way you control the light coming into the camera. It is how much light you let in through your lens. The size of the opening on your lens is shown in f/stops…like f/2.8 or f/22. F/2.8 creates a really big opening in the iris of your lens…lets in a lot of light. f/22 creates a really small opening in your lens and lets in a very small amount of light.

Remember…it is the combination of how much light you are letting in….for how long…and how sensitive the sensor or film is to that light…that all add up to the image you capture. Too little of any of those components and you are under-exposed and the image is too dark to use….too much of any of them and the image is over exposed…too bright to be used.

Aperture is also a key component to depth of field (DOF) that we will get to in another article. It basically means how much of the photo is in sharp focus…anywhere from just a tiny spot with everything else blurred…like the shot of the eye of spider taken by a specialty macro lens….or a shot of the Grand Canyon where everything from three feet in front of the camera to the horizon is all in focus. That is depth of field. As a general rule…the higher the aperture…like f/16, f/18 or f/22…the more of the photo will be in focus. That is enough on DOF for now.

There is an old saying…F/8 and wait. That basically means that f/8 is a pretty good middle ground for most photos. So, set your ISO at anywhere from 100 to 400. Set the little dial on the top of your camera to A for Aperture and then set the aperture setting to f/8. Now go outside in the daylight and take a few photos. The camera will be choosing the speed of those photos for you…so try landscape shots and portraits rather than swooping birds or race cars. Congratulations…you have controlled quite a bit and you should get some nice shots…and again, you are really just one step away from shooting in full Manual…your eventual goal.

You now know how to control for speed and for how much light you are gathering…one more control in the next article. Aloha.

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