Aperture Priority Mode

by | Equipment, Technique

Is it OK to shoot in Aperture Priority Mode?  Yes, it definitely is.

I’m always talking about shooting in Manual Mode. Professional photographers need to be able to shoot in Manual Mode, it’s a must-have skill.  You need to have control of your camera.  There are other settings though on the mode dial, they are Manual Mode, Aperture Priority, Shutter Priority, and Program Mode. Disregard the picture icon modes, they are preset and won’t help you.

Program Mode [P] – This setting is basically AUTO. You have zero control, don’t use it. I forbid it!

Shutter Priority Mode [S] [Tv] – This is the next shooting mode you will probably never use. When you use Shutter Priority it allows you to choose the shutter speed and the camera sets the aperture. If you want to change the aperture you need to change the ISO setting. This mode is counterintuitive. You are losing control of the depth of field (DoF) which is controlled by the aperture setting.  Remember, the aperture is the first setting to consider when shooting in Manual Mode.

I have never heard another professional photographer say they use Shutter Priority Mode.  It just isn’t needed.  So I’m going to advise you to give it a miss.

Manual Mode [M] – You already know about it if you’ve listened to The Exposure Triangle episode on the Photography Q&A Podcast or read the Exposure Triangle in the free download section of the website.

You need to be able to shoot in Manual Mode, but Aperture Priority Mode is an excellent sidekick that you will be able to use in lots of situations.

Aperture Priority [A] [Av] – When your camera is in Aperture Priority Mode you set the aperture, and the ISO. The camera sets the shutter speed based on the aperture and ISO settings. If the shutter speed is not high enough for the situation, you can turn up the ISO, which in turn will raise the shutter speed.

It can really make your life easier in changing conditions.

When I used to shoot dog agility competitions I would use Aperture Priority Mode if there was alternating sun and cloud.  If the sun disappears behind a cloud the camera changes the shutter speed to a slower setting to get more light in.

I know I want 1/2000 shutter speed to freeze the action.  So, if the camera set the shutter speed below 1/2000, I would turn the ISO setting up to get the speed I needed.  When the clouds moved on and the sun was shining the camera would get more light and automatically change the shutter speed to a faster one of say 1/2500 or 1/3200. Remember, a shutter speed faster than you need isn’t a problem.

Another situation in that I would use Aperture Priority is during a wedding.  If it was a church wedding I would use Manual Mode inside the church and Aperture Priority outside.  As the family and friends come out of the church and congregate outside, I would walk around with my 70-200mm capturing all the happy faces.  One minute the sun was behind me, then to my side or head-on.  As long as the shutter speed is fast enough it was fine.  If the shutter speed dropped too low, say below 1/200 I just had to up the ISO and the shutter speed went up.

You have to think a lot less about your setting when shooting in Aperture Priority Mode.

15 years ago I was told to only shoot in manual mode so the camera has less to think about or process.  That was true when I was shooting 5 frames a second with a Canon 30D in Aperture Priority Mode. Some of the images didn’t have the same colors. The first 2 were fine but the next ones were lacking. Shoot 5 images a second in Manual Mode and it was great.

Today’s camera bodies are light years ahead of cameras from 10+ years ago and have incredible processing power. I wouldn’t worry about shooting in Aperture Priority in any situation.

I have to say it’s a very relaxing mode to shoot in.  Think about it, all you have to do is set the aperture and then turn the ISO up if the shutter speed isn’t fast enough to freeze the frame.

Then just shoot, and the exposure meter is balanced by the camera.

If you find Manual Mode a bit overwhelming, use Aperture Priority Mode.  You are still in control of your camera.

Just remember, don’t ever turn the mode dial to [P].  Program Mode will kill your creative brain cells.

Don’t bother using [S] [Tv].  Shutter Priority isn’t necessary, give it a miss.

Shooting in Aperture Priority Mode

OK, so when you are shooting in Aperture Priority Mode you need to take these steps when setting up.

  1. Turn the Mode dial to [A] or [Av] on a Canon.
  2. Decide what Depth of Field is needed and set the appropriate aperture. Use the Photopills App if necessary.
  3. Set the ISO to 100
  4. Decide what is the minimum shutter speed you need to freeze the action. If the camera has set the shutter speed lower than you need, then turn up your ISO until the shutter speed is where you want it.


Shooting kids running. This needs a shutter speed of 1/800.  If the camera sets the shutter speed to 1/400 it is 1 stop lower than you need. So you need to turn the ISO up 1 stop.

ISO 100 + 1 Stop = ISO 200

You could just push the ISO button and turn the dial until the shutter speed is at 1/800.  It is better to think of these settings in terms of stops.

Now if you want a shutter speed of 1/800 and the camera sets it to 1/1000 you don’t need to change anything. Just shoot!

Remember, when choosing a shutter speed you need to know h\what the slowest speed setting you can use to avoid blurry images.

  • For portraits use 1/125 minimum
  • Walking speed use 1/250 minimum
  • Running use 1/800 minimum
  • Fast subjects use 1/800 – 1/4000

If you only need 1/125 for a portrait and the camera sets the shutter speed to 1/800 that’s fine, leave it like that.  When it’s lower than 1/125 turn up the ISO until the shutter speed is at 1/125.

That’s it, Aperture Priority Mode is very easy to shoot in. Give it a try.