The most common question I’m asked, by far, is “how do I make my backgrounds blurry?”.
(The second most common is how to not be so wiggly and get nice, sharp pictures….that’s for another post!)
Trying to create a nice blurry background is actually how I started my obsession with photography. Naively, I thought that all I needed was a prime lens (like the 50mm 1.4) and I would be set. I thought it would automatically create beautiful blurry backgrounds for me…
And very quickly I realized how wrong I was.
I couldn’t figure it out. If I was shooting at f1.4, why weren’t my backgrounds blurry? They were a little bit blurry, but not like I saw in so many professional images out there. What was I doing wrong?
The answer is not as simple as you might guess.
It is a blend of four factors, three of which we have control over, that I’ll talk about today.
But first, what exactly is background blur?
Background blur is a result of “depth of field,” which actually refers to the part of your photo that is in focus…not blurry. (This comes into play later on!)
The three main things that help to create “background blur” are lens focal length, aperture and distance.
Lens focal length
This is “mm” you see on your lens. So, if you have a prime lens (i.e., it doesn’t zoom), then your focal length is fixed, such as a 50mm lens. If you have a zoom lens, the focal length is shown on graduations around your lens.
In general, the longer the focal you use, the easier it is to create background blur, due to how longer focal lengths compress the background (they show less of a scene). Longer focal lengths also have a shallower depth of field (keeping everything else equal), due to the optics of the lens.
The optics of your lens create perspective and distortion, which is why, with a wide angle lens, you can see so much more of the background than you can with a telephoto lens.
With longer focal lengths, you’re going to have to get further away from your subject in order to fit them in the picture, because you’re so zoomed in. This is why I personally don’t like using long focal lengths with kids – because I’m too far away to interact with them. That said, they are ideal for weddings, when you don’t want to be intrusive on your bride’s special day, yet you need to get close to the action.
The following image set shows the effect focal lens length has on your final image.
Neither Wesley (my son) nor I moved positions. All I did was zoom my lens out each time.
But lens focal length isn’t even half the story…
The “big player” in creating beautiful blurry backgrounds is aperture.
Aperture
Aperture refers to how big the hole is inside your camera that light passes through in order to record a picture. It is referred to in f stops, because, as the number increases (from f4 to f5.6), less light is let in (it is being “”stopped down”). I remember what aperture does by comparing it to the pupil of my eye. When it’s dark, my pupils dilate and get bigger to let more light in. Same goes with aperture. The wider the aperture, the more light is let in. (Makes a bigger hole!) Wide apertures are represented by smaller numbers. So an aperture of f1.2 is actually larger than an aperture of f2.8.
What does this have to do with blurry backgrounds?
One of the side effects of changing aperture is that as your aperture gets wider (closer to 1.0 so it lets in more light), the depth of field shrinks, so less of your photo will be in focus. That’s why you here photographers saying they always shoot “wide open” to get those beautiful blurry backgrounds. It means they’re shooting with wide apertures like f1.2 and f2.8.
When you combine that with a longer focal length, the “blurry” effect is increased. Now, I did some research on this, and it turns out you actually get similar levels of blur shooting with a 50mm lens at 1.8 as you do with a 200mm lens at 5.6 HOWEVER, the focal length controls how close your background appears relative to your subject. So it’s a matter of your personal preference.
Backgrounds in images with longer focal lengths may appear to have more blur, because the background is actually larger (more magnified.)
The image set below shows you how changing your aperture from wide to narrow changes the amount of “background blur” in your final image. Neither Wesley or I moved positions. I simply altered the settings on my camera to ensure a consistent exposure for each image.
But wait, we’re not done yet! There’s one last thing to add in to the mix.
Relative Distance
If my subject was standing against a wall, and I was shooting “wide open” with a long focal length, like 200mm, there would be absolutely NO background blur in the final image. Why? Well, remember I told you how aperture determines the depth of field (the area of your photo that is in focus)? If your subject and your background are basically in the same plane, they’ll both be in the area of your photo that is in focus, hence - no background blur.
The last piece of the puzzle is the relative distance between your subject and your background (and you!).
You need to get your background out of that area of focus. And you do this by moving your subject away from your background, towards you. The closer your subject is to you, the blurrier your background will become. This also increases background compression.
So what does all the information amount to?
In order to create a blurry background easily, you need the following:
- a longer focal length lens
- a wide aperture
- and good separation between your subject and your background.
And yes, you need to have a good background. And the closer your subject is to YOU, the easier it is to separate them from the background.
Here’s a list of common questions I get after I explain this (with my suggestions):
Q: I want my background to be blurry AND have the whole person in the picture, not just their head. How do I do that?
A: You’ll need a loooong focal length, such as 100mm or 200mm, combined with a wide aperture, like 2.8. (The 85mm f1.2 lens also works wonders!) And you’ll have to back waayyyyy up in order to get the whole person in the image. Ensure there is a good distance (like, 15-25m) between them and the background. And click away!
Q: What if I just have a kit lens? Can I still make my backgrounds blurry?
A: YES! It’s totally possible. Kit lenses typically don’t have quite as wide apertures – usually 3.5 to 5.6, but don’t let that stop you. Zoom your lens all the way in and set your aperture as low as it will go. If you photograph smaller things, such as heads or little babies, it’ll be easier to create that blurry background.
Q: OK, this is all too complicated for me. Can you give me the EASY way, a set it and forget it sort of thing?
A: YES! If you’re not comfortable shooting in manual, but don’t like the way your images are turning out using “P” or “auto” mode, then turn your camera dial to “Av” or “A” mode on your camera. This gives you the ability to control aperture only. Set your aperture as wide as it will go. (i.e. the lowest number, probably 3.5 or 5.6). Now zoom your lens all the way in. Your camera will set everything else. Again, ensure there’s separation between your subject and your background and you’re good to go!
One last thing (and it’s really important so read on!)
All the information in this post assumes you know how to control your focus - because, if you’re letting your camera decide what should be in focus, you’re leaving a very important piece of the puzzle up to a machine. And that’s what we’ll be talking about next week!
What’s your biggest struggle with your photography knowledge? Let me know in the comments and get the conversation going!