E is for Exposure

Exposure - Photography is all about exposure to light and our tools to create an exposure that matches the image in our mind's eye are the triumvirate: Aperture, Shutter Speed and ISO. Let me focus first on Aperture and Shutter Speed.

I never shoot in the fully automatic setting available on my Nikon D90, rather I select Aperture or Shutter Speed depending on what I'm shooting. If I'm shooting a landscape or something static I will select aperture and then begin the thought process of how I want the image to look. If the background is messy I might want a shallow depth of field to throw the mess into a colorful blur so I'd select a low f stop number, or I may want as much of the image in focus as possible as it may all contribute to the story in the image so to maximize the depth of field I'd select a high f stop number.

Let me give a simple example of an image that is the same exposure but with differing results. For ease of demonstration, all of theses photos were taken on Aperture Priority with an ISO of 200. The only setting I changed was the Aperture; the camera adjusted the shutter speed accordingly to achieve a good exposure. Can you see the difference in the depth of field?

1/30 second at f/22 
Notice the blur of the moving palm fronds but the detail in the background. You can see the ocean especially in comparison to the last image below.

1/60 second at f/16

1/125 second at f/11

1/250 second at f/8.0

1/500 second at f/5.6
Notice the soft background resulting from the shallow depth of field created by the large aperture. You can hardly see the ocean.

"The same exposure can be achieved with different combinations of aperture and shutter speed. Fast shutter speeds and larger apertures freeze moving objects and soften background details [like the last image above], while slow shutter speeds and small apertures blur moving objects and bring out background details [like the first image above]." This is directly from my camera's manual and I can honestly say I "get it". Do you?

 

Comments

[Nancy Lanzoni]

Claudia, I love the simple explanations. It's so much easier to remember. I knew it all once upon a time but, with the advent of "auto everything," got lazy and then forgot everything! Thanks!

[Claudia Ward]

Glad you find this helpful. Let me know if you want me to cover something specific, or if you have ANY questions.