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Learning Your Camera Part III-Aperture Priority

Now that you have had some time to experience the Program (P) mode on your camera let’s try something new. Click the dial over one more spot to the Aperture (Av-if you use a superior Canon camera, A if you use a capable but lesser Nikon camera) mode. Aperture mode allows you to have control of ISO and whether or not you want your flash to fire. Shutter speed will be determined by the camera.

diagram of different aperture settings

Various Aperture Settings

The top left aperture diagram would illustrate a aperture that had been “stopped down”. For example-that setting might be something like f/22. The bottom right aperture in this diagram would be something like f/2.8. Referencing these examples shows what a difference aperture settings can make in relation to how much light passes through the lens into the camera.

Let’s back up one step and discuss what Av mode is going to allow us to do. Controlling aperture is going to control how much light we allow to enter the camera and how well it is focused through the lens. Changing the aperture setting opens or closes a diaphragm inside the lens. A wide open aperture will allow more light to enter the camera, but in a less organized way. A narrow aperture will let less light in, but in a more organized way. Controlling light in this manner will give great creative control of what we can capture and what we want to be in focus or out of focus.

Aperture readings are essentially fractions-but are not displayed as such in our camera settings. An f 2.8 aperture is technically 1/2.8. A f/16 aperture is 1/16. If you can remember this nuance it will make more sense that f /2.8 actually means the diaphragm in the lens is more open than f /16.


colored pencils

Pencil Macro Shot Illustrating Depth of Field

So why do we want to mess with this aperture setting anyways? Here are some reasons:
  • Control what is in focus-or not in focus. This is also referred to as depth of field. For instance-shooting a person or group of people at f /2.8 would allow blurring of the background and drawing focus to the main subject. When shooting a landscape more of the image would generally need to be in focus. Shooting at f /16 or a closed down aperture would be preferred.
  • Low light conditions would lead us to use a more open aperture to allow more light to reach the sensor. Conversely shooting in conditions with excess light might lead us to closing down the aperture to let less light to the sensor.
  • Closing down the aperture can give neat effects i.e. lens flare, and sun burst effects.

Be sure to turn the trusty camera dial over to Aperture priority mode and give it some practice. Here at Shutterhogs we are obviously big proponents of learning to use the Manual mode-but that does not negate the usefulness of other modes. Aperture mode is good for those situations where you know for certain what effect you want to achieve with aperture but may not have time to work out the shutter speed. Some shooting situations may change too rapidly to allow you to modify settings. Aperture priority mode with the ISO setting set to Auto can help you in those situations.

Shari HartOctober 27, 2012 - 7:41 pm

Hey! What do you mean ‘capable but lesser Nikon’??? 😉

Thanks for the informative and useful article!

TayoIBOctober 31, 2012 - 11:17 am

Very informative articles, thanks for the info. How useful is the aperture setting when taking pictures meant for HDR?

Alex SmithNovember 10, 2012 - 1:15 pm

The aperture setting is critical in an HDR image. For HDR you want to maintain a constant aperture and only change the shutter speed to vary the exposure. By keeping the aperture constant you will maintain a constant depth of field so when you combine the images in processing, all the areas that are in focus are the same across all images. Thus, a typical series would be three shots all at let’s say f/16 with 3-5 different shutter speeds each a stop or so apart. Hope that helps. Thanks for dropping by the site.


WillDecember 22, 2012 - 5:08 am

“Superior Canon camera.” I love it! My first camera (first after my Polaroid One Step – yeah, I’m showing my age 🙂 was a Canon AE1, and I haven’t looked at another brand since. I spent 27 years in the Navy and must have taken a million photographs. Okay a million pictures and a few thousand photgraphs. My trusty Canon went with me everywhere my ship or aircraft went. My favorite place for photography was Thailand, closely followed by Sicily. In the States Maine must have given me the majority of my photos. I never got serious about the mechanics of photography until I retired in 2006. I always had an instinctive feel for what was right for the shot but I still had more misses than hits. I’m a big fan of B&W photos for the times I want to convey mood, but living overseas so much let me see the color in the places I visited. Getting asway from the city and into the villages and rural backroads was so rewarding. Cities are the same wherever you go but the villages are where you see people and the culture they spring from. My camera is always set to automatic for those shots that just seem to spring into view as I am passing by. Manual setting comes when I have time to compose. We’ve come a long way from Mom’s instamatic with the Sylvania flash bulbs.
Shutterhogs and DPS are my field manuals 🙂

adminDecember 29, 2012 - 11:52 am


I bet you have some amazing photos from your travels. The digital photography revolution has definitely made things easier for the average photo enthusiast. Heck, now we can change ISO between shots without the need to change film in the camera. You should consider digitizing/scanning some of those photos you have taken and share them for others to experience. Thanks for stopping by the site.


Aunt D.January 3, 2013 - 4:15 pm

I have a problem…none of the pictures in your articles are showing up…they only show as a red x….please advise…thanks

adminJanuary 9, 2013 - 12:30 pm

Hi Deb,
We had to do some website maintenance and apparently the images did not reload properly. We are working on getting it fixed. Thanks for making us aware of this though.


adminJanuary 10, 2013 - 12:05 pm

All of the images should now be working. Thanks for notifying us. Enjoy!

PattiMarch 12, 2013 - 8:43 am

I’m a digital photography group leader. I’d like to use your photos in a short video I created through Animoto. This is for a non – profit organization. No money comes from attending meetings, only member dues. Membership is not required.

Pleas let me know if I have permission to use your photos. I will give your credit, with photo and links. Thank you for creating a wonderful site. Have a great day!

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