Aperture

Aperture refers to the hole in your lens that allows the light into the camera. The size of the hole affects the amount of light coming in and the depth of field. It’s measurement is called an F Stop. An F Stop is a fractional degree of light so to explain simply, the bigger the opening the smaller the F number and the larger the opening the larger the F number. Aperture works Incrementally so therefore with each step down the aperture blades let in half as much light.

Image courtesy of http://www.photographylife.com

Aperture Scale

From top to bottom I have listed F Stops from large to small. Starting at f/1.4 which is a very large opening of your aperture blades and lets in lets in a lot of light to f/32 which lets in barely any. Each stop let’s in half the amount of light.

f/1.4
f/2.0
f/2.8
f/4.0
f/5.6
f/8.0
f/11.0
f/16.0
f/22.0
f/32.0

These are the main aperture “stops,” but most cameras and lenses today let you set some values in between, such as f/1.8 or f/3.5. Which I will demonstrate with my camera in exercise 4.1 below.

Activity 4.1: Aperture and depth of field

For this activity you will need to find a long, uninterrupted subject or scene such as a fence, ladder, ruler or path. Using this subject you will shoot a series of images utilising your full available aperture range.

Set your camera’s shooting mode to Aperture priority (A/Av) and begin with the widest aperture available on your lens (e.g. f/1.4, f/3.5).

Without moving the camera, shoot multiple images throughout the aperture range (i.e. f/4, f/5.6, f/8, f/11, f/16, f/22).

Compare the final images. How did your aperture settings affect the depth of field in each image? How did each aperture adjustment affect your other exposure settings (i.e. shutter speed, ISO)

The Results

I set my camera to Aperture Priority mode, selected the largest aperture on my f/5.6 18-55 mm kit lens and walked down to the front of our complex where there is a long brick fence so I could demonstrate this exercise. The largest aperture I can set this lens to is F/5.6 so I started with that and cycled through 17 shots to F/36. As you can see with the gallery below the depth of field , sharpness in the foreground and background as well as colour changes slightly with each image. For the metadata on each image if you click on an image in the gallery it will display it with a larger image on a side scrolling gallery with the Focal length and aperture as well as ISO for each shot. All images are unedited and loaded into Lightroom before sending to my Dropbox as jpgs rather than RAW.