Understanding Aperture Overview & Refresher

Choosing Exposure Modes Aperture Priority Mode Lets you choose the aperture needed to obtain the depth of field you want and the exposure system automatically sets the shutter speed to give you good exposure Select this mode when depth of field is important. Landscape: Select small aperture - sharp Close up Photography: Select small aperture Throw the background out of focus – select large aperture

Aperture Controls Light and Depth of Field The aperture adjusts the size of the opening through which light passes to the image sensor. The aperture can be opened up to let in more light or closed (stopped down) to let in less. Smaller aperture lets less light strike the image sensor, so the image is darker. The larger aperture lets in more so the image is lighter.

Low versus High A lower f-stop number opens the aperture and admits more light onto the camera sensor. Example: f/1.4 A Higher f-stop numbers make the camera’s aperture smaller so less light hits the sensor. Example: f/16

Aperture Controls Light and Depth of Field As with shutter speed, aperture affects the sharpness of your picture Changing the aperture changes the depth of field The image to the right shows two examples – the photo in the forefront represents what happens when the aperture is set larger. Notice the image in the front is very clear and sharp. Large aperture opening Small aperture opening

Depth of Field The “Depth of Field” is the distance wherein objects are in focus. There are times when you desire a great depth of field, i.e. where objects both close to you and far from you are in focus. This is especially true when you are taking a landscape picture and want as much as possible to be in crisp focus. Then there are times when you want to isolate your subject, as when you are taking a portrait and want your subject to be in sharp focus but the background to be out of focus. In this case, you desire a shallow depth of field.

Aperture Controls Light and Depth of Field Aperture settings are called f-stops and indicate the size of the aperture opening. Remember them like fractions: 1/11 is less than 1/8, just as the size of f/11 lens opening is smaller that the size of f/8 opening. The red and blue are the one third and one half aperture settings found on high end digital cameras. To get smaller apertures, increase the ISO. Smallest Larger

Using Aperture For maximum depth of field, with entire scene sharp from near to far, you need a small aperture. When photographing landscapes and portraits aperture priority mode is favored because it gives you direct control over the aperture and depth of field. Increase the ISO speed of your digital camera manually to allow a faster shutter speed or smaller aperture. The results will have more noise (grain-like appearance) but they will be sharper with more depth of field.

Rules of Thumb for Aperture The rule of thumb is this: Select a large aperture (or small f/value or small aperture value), e.g. f/2.8, to obtain a shallow Depth of Field. (background out of focus, foreground clear and sharp) Portraits or close up Use tripod! Select a small aperture (or large f/value or large aperture value), e.g. f/8.0, to achieve great Depth of Field. (background and foreground are in focus) Landscape or entire scene

REMEMBER! Practice Makes Perfect... Experimentation... Creativity... HAVE FUN!