How to take a photo with a blurry background

Understanding aperture and how to take a photo with a blurry background

So you have a new camera, and you’re dying to take a professional looking portrait photo. You know, the type of photo where your subject is in perfect focus, but the background is soft and blurry. How do you do it? It all starts with understanding aperture.

How to create a blurry background is the #1 thing people ask me when it comes to taking artistic photos.… My answer is always the same: that they need a low aperture lens.  You might have heard the word aperture before, but what the heck is it? Aperture is the main factor in whether the background of your photo is blurry or not. Understanding aperture can be SUPER confusing, so I wanted to do a post on what it is and why it’s important. I’m a fan of cutting through all the junk, so let me give you the down and dirty short version.

Photo with blurry background caused by a low aperture lens. Photo by Krista Lee, Krista Lee Photography / Real Life Captured
This photo was taken just after sunset with my 85mm lens, 1.8 aperture and ISO 100. Don’t mind my child’s hair… At the time I was REALLY struggling with how to style his coarse hair LOL

In a nutshell, aperture is how a lens makes the background of your photo blurry or not blurry. Pick a low number ( like aperture 1.2) and 99% of your photo will be blurry and soft, with just a very small part in focus (like your subject’s eyes). Pick a high number (like aperture 22) and everything in your photo will become sharp. Having a low aperture can also come in handy if you’re stuck in a dark room without a flash. Let’s say you want to take a photo of your sweet baby asleep in a darker or low-lit room, but you don’t want to open the windows or turn on your flash (because you definitely don’t want to wake that baby!) Low aperture lenses to the rescue! Use a high ISO (6400) ISO combined with a low aperture lens setting (1.4, 1.8) and you’ll likely get the shot. Try shooting that same photo with a higher aperture, and nope–your photo will be pitch black.

Night photo using a low aperture and high ISO. Photo by Krista Lee, Krista Lee Photography / Real Life Captured
Photo taken at night with just her night light and hall light on. ISO 6400 Aperture 1.4, notice the grain caused by high ISO.

How to take a photo with a blurry background

I’ll go over this in more depth in my Learn To Use Your Camera course, but I’m going to give you the free basics right here!

(If you have not setup your camera yet, be sure to watch this video to ensure that your camera is set up correctly before proceeding.)

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1. Make sure you have a low aperture lens

I personally consider “low aperture” to be 2.8 or lower. How do you tell what aperture your lens is? On your lens (either the front or top) there will be a little number that says “1:2.8” or “1:3.5”. The number AFTER the colon will be the aperture of your lens. Depending on the brand, your lens may also say F/2.8. After the “F/” is the lowest aperture of your lens. If this number is higher than 2.8 or 3.2, it will be more difficult to get the coveted blurry background. Don’t have the correct lens? See my favorite low aperture lenses in my prior article.

How to determine what aperture your lens is. A Canon 50mm 1.4 lens is pictured here, Photo by Krista Lee, Krista Lee Photography / Real Life Captured
How to determine what aperture your lens is. Pictured is a Tamron 28-75mm Canon mount lens 2.8 aperture. Photo by Krista Lee, Krista Lee Photography / Real Life Captured

2. Set your dial on top to “AV” for Aperture Priority

Set your dial on top to “AV” for Aperture Priority
This semi-automatic mode is going to let you tell the camera what aperture you want. If you want a super blurry, out-of-focus background, choose AV mode and then dial in your aperture to the lowest setting your lens will allow (2.8 or lower, preferably). See your camera manual (or Google yours) to change your aperture setting if you don’t know how to do that already. (I’d explain here but every camera model is different, so I’d have to go through hundreds of scenarios!)

This semi-automatic mode is going to let you tell the camera what aperture you want. If you want a super blurry, out-of-focus background, choose AV mode and then dial in your aperture to the lowest setting your lens will allow (2.8 or lower, preferably). See your camera manual (or Google yours) to change your aperture setting if you don’t know how to do that already. (I’d explain here but every camera model is different, so I’d have to go through hundreds of scenarios!)

To get aperture priority on a Canon, dial the top dial to AV. Photo by Krista Lee, Krista Lee Photography / Real Life Captured

3. Set your ISO rating

Unlike your iPhone, a DSLR camera allows you to completely control every aspect of the camera. Eventually, I’d love for you to be shooting in 100% manual mode (which essentially is where you tell the camera exactly what you want it to do instead of letting it decide for you). For now, we’re going to shoot in a semi-automatic AV mode. To start that, you’ll need to choose an ISO. What is ISO? ISO tells the camera if it’s light or dark in the room you will be taking the photo. If you’re in a super dark room, you’ll want to set your ISO to 6400. If you’re outside in the bright sunshine, you’ll want to set your camera to ISO 100. Everything else is just a gradient in between these numbers. Outside in the middle of the day, but it’s cloudy? Try ISO 400. Inside but it’s kind of bright? Try ISO 800. Keep in mind, it’s OK to guess on this. As pro photographers, we walk into a room and think “Ehhhh, 800 ISO?” (Sounds scientific, right? LOL) We set our ISO, then adjust later if needed.

Look on the camera display to view ISO and aperture.

4. Take a photo

I’m assuming your white balance is set, and your camera is on auto focus. If not, take a minute to set this, and then, ta-da:  take a photo!

Congratulations! You have now taken a low aperture photo. Take a second to pat yourself on the back. You can make this blurry effect even better by shooting in an area where there’s not much behind your subject (like an open field!)

How to take a photo with a sharp background

Let’s say you don’t want a blurry background, but  instead you’d like numerous things to be in focus. Photos with sharp backgrounds typically require a LOT of light. These photos are best taken outside in a brightly lit area. Easiest solution? Get outside. Set your dial to AV as instructed above, and set your aperture setting to at least 11. Background still not sharp enough? Try upping your number until you find that it’s sharp enough, you can go all the way up to 22. If your photo gets blurry or dark, try upping your ISO to 1600 or higher.

Photo of using a very low aperture, lots of blur and bokeh in the background of the photo. Photo by Krista Lee, Krista Lee Photography / Real Life Captured
1.8 aperture – Ah! Look at that beautiful blurry background
Photo of 3.2 aperture. Photo by Krista Lee, Krista Lee Photography / Real Life Captured
3.2 aperture – A little less background blur, but still quite a bit
Photo of F22 aperture. Photo by Krista Lee, Krista Lee Photography / Real Life Captured
22 aperture – All in focus. Notice the grain, though. Doing a high aperture sharp photo in low light requires your camera to keep the shutter open longer and can also require a high ISO, sometimes resulting in unwanted grainy images. Do this type of photo outside in a bright area to avoid the grain issue.

Aperture by Definition

For a bit more photo education, take a look at these proper definitions:

Aperture : A space through which light passes in an optical or photographic instrument, especially the variable opening by which light enters a camera.

Another definition: “More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane.”

Honestly, when I first started out, the definition of aperture confused the living crap out of me. While the definition is accurate,  you don’t have to worry too much about it right now. Just try to focus on these 3 things when it comes to aperture:

  • Do you want a blurry background?
  • Conversely, do you want your entire background to be in focus?
  • Are you stuck in a dark room with no flash?

THESE are the situations where aperture is your friend and you’ll need to set it manually in your camera.

Aperture can be a very confusing subject! Remember that setting your aperture is especially important if you want a blurry background, a sharp background, or if you’re photographing something in a dark room. Leave a comment below if this helped, or if you have any questions. Happy shooting! – Krista

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Krista Lee is a Nashville, TN based portrait and wedding photographer. See her work and professional site at www.kristaleephotography.com

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