“Why Use Aperture Priority”


Bettye Sue Austin

I was using the manual mode each time I shot photos.  Then I tried aperture priority mode.  Now I use this mode 99 percent of the time.

Aperture priority (AV or A) is a semi-automatic mode found on DSLR cameras.  Its main function is to give you control over depth of field (DOF) and sensitivity to light (ISO) while letting the camera automatically adjust the shutter speed (SS), ISO, and sometimes white balance, based on the selected aperture.  DOF is controlled when you select the desired aperture manually.  When you set the desired f-number, the camera can select the shutter speed settings and ISO to produce a properly exposed image.  The lower the f-number like 1.4, the shallower the background.  This causes a blur of the background so you can isolate the subject with a soft background.  Higher f-stop numbers like f/8 and above means everything will be in focus.  The f-stop limits are different for different lenses.  Shooting in the AV mode frees you up to check the composition and other aspects to get the most appealing image.

I always set my ISO to 100 or what the lighting requires.  I set the white balance to conditions of the day.  If you set your ISO to AUTO, noise or grain may appear in your photos. There will be times when the light is not good or you are shooting at night so aperture priority would not be the mode to use.  I usually never use AV if shooting snow scenes.

These two Zinnia photos were shot with my Canon 6D 50mm lens.  The first one is shot in manual mode with the camera setting f/2.8, ISO 100, 1/160 sec. 

The second one was shot using the same lens in aperture priority mode.  The camera produced the same setting for both images.

In another test, the two Hydrangea photos were shot using my 24-105 lens first in manual mode and then in aperture priority mode.  Note that the camera produced the same setting (90mm, f/5.6, ISO100, 1/100 sec) for both images.

As you can see the settings were the same with both manual and aperture priority in both tests.  This will not happen every time you test.  This does show that you can trust the aperture priority mode.  This will free you up to pay more attention to the composition.  You decide which aperture you need, one that has a soft background or one that is more in focus.

You are welcome to come to our camera club meetings at the Cookeville Art Studio and Gallery, 186 S Walnut Ave Suite A, Cookeville, TN 38501.  We usually meet on the 2nd Monday of the month.  The meeting starts at 7pm.  Check out our schedule on the website https://www.cookevillecameraclub.com/