What is Aperture?

Written by: Derek Watterson

THE APERTURE is built inside each lens and it controls the light entering a camera.  A lot like the shades on a window control the light:

“Stopped down” f16 or f22

“Optimum” f8 or f11

“Wide open” f2.8 to f4.5

Measuring Aperture

Aperture is measured in f stops. The larger the number under the f, the smaller the hole (aperture) and the less light that comes in.

A wide open aperture results in a shallow depth of field whereas a smaller aperture results in a great depth of field. If you want to know why this is see our lesson on the Physics of Depth of Field.
If you’re interested in knowing what the “f” is about in all the aperture settings see our lesson on “Aperture F Number“.

This entry was posted on Monday, April 7th, 2008 at 9:27 am and is filed under Beginner, Photography Lessons. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

6 Responses to “What is Aperture?”

1. Jill on May 18th, 2010 at 9:26 am

   I’m interested in buying DSLR camera. From your lessons (very helpful, thank you) it seems like the reason my cheap digital camera photos are so “bad in quality” is because the aperture is not adjusted correctly. Reading through your lesson about aperture, it explains what the aperture is for, and how it should be adjusted, yet it does not explain how to adjust the aperture, or if it is even adjustable. Do I need to look for a camera that has a wide range of aperture settings? Do all cameras have the same range of settings?

2. Nitin on September 5th, 2010 at 5:30 am

   Hi,

   I guess f stands for the focal length of the camera lens. Which means i can open the camera aperture to a max of f/1.4

   Pls. correct me if i am wrong here..i am new to this photography thing and learning through your website.
   Really nice and easy way of explanation which is clear to a layman.

   Good Work. I am really enjoying it and recommending it even to my friends who are interested in photography.

   Regards
   Nitin

3. Charlotte on February 23rd, 2011 at 7:14 pm

   How would you say that in speech? “F one point four”?

4. Digital Photography on February 24th, 2011 at 8:09 am

   F stop of 1.4. Each setting is referred to as a “stop” in aperture.

5. angela hand on April 8th, 2012 at 6:53 pm

   Great lesson.

6. Isabel on February 8th, 2013 at 3:34 am

   Thanks for helping all of us who are new to photography

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