How to make the background blurry and keep the subject in focus

You’ve seen the photos where the background is blury and the subject is in sharp focus. How did they do that? It’s easy. And this quick article will explain exactly how to do it.

There are 2 easy ways to make the background out of focus while keeping the foreground, or subject, in focus:

1. Use a zoom lens – If your kit lens has zoom capability you’re all set. Just zoom all the way in (maximum zoom), and get your subject in frame. You may have to back up some. This may be counterintuitive at first, because you’re probably accustomed to using your zoom only when something is far away and you want to bring it closer. But this technique will deliver the effect you’re looking for, and it’s just that simple! It also helps if the background is not too close. The farther away, the better.
2. Use a lens with a low  f stop number – First of all, what’s an f stop? This is the aperture that your lens will produce. It’s noted on the side of your lens. Many times it’s a variable number, like on my Nikon 18-200 zoom it’s f/3.5-f/5.6. That means if I have the lens zoomed out at 18mm (wide angle) the maximum aperture (or “f stop”) I can get is f/3.5, and at 200m it’s f/5.6. An example of a popular continuous aperture lens is the Nikon 70-200 f/2.8. It stays at f/2.8 at any focal length, regardless of whether you’re at 70mm or 200mm. These wide aperture lenses are normally expensive. Fortunately, they’re affordable to rent. Also referred to as “fast glass” by photographers, these lenses allow you to easily get that blurry background and tack-sharp subject you’re looking for, regardless of whether you’re zoomed in or out. The only caveat to this technique is that the subject has to be somewhat close to you. But the longer the lens (telephoto) the farther back you can stand. Sports photographers and nature photographers use super long lenses, like 400mm, 500mm, even 600mm and still get shallow depth of field.

Making the background blury while keeping the subject in focus is particularly handy when taking a portrait photo. It makes the subject “pop” and keeps your attention on the subject so your eye isn’t distracted by what’s in the background. There are many excellent portrait lenses. The highest quality lenses have that continuos f stop and allow you to easily shoot with less light and get that shallow depth of field (low f stop) or “blury background” you’re trying to achieve while keeping the subject in crisp focus.

One of the most affordable high quality lenses that allows you to use the continuous f stop is the 50mm. The Nikon 50mm f/1.4 is an example of what is sometimes called the “Nifty 50,” or the “Thrifty 50.”  It’s a high quality lens that allows you to do some really fun stuff without breaking the bank:

• Achieve that shallow depth of field, or “fuzzy background.”
  

  Shallow Depth of Field Example

  • Shooting portraits with shallow depth of field also allows you to shoot in cluttered, or places with distracting backgrounds (i.e. playground, or inside) without revealing the details of the background.
• Shoot in low light. Because it’s “fast glass” and has a continuos f stop you’ll be able to shoot in lower light conditions without a flash. Shooting on the lowest aperture number is referred to as shooting “wide open” (this is the name of my blog!). References to shooting with a large aperture actually mean shooting with a low f stop number (an inverse relationship, if you want to think of it that way), where the lens is as wide open as possible. Shooting wide open can be preferable if you’re in a museum, for instance, or taking a portrait of someone in marginal light conditions. You’re shooting wide open – you’re letting in as much light as possible, while still allowing for an acceptably quick shutter speed.
  • Shooting in low light (like in the forest), or without a flash, can be helpful when photographing newborn babies or kids. If you want to capture some beautiful images of your baby try using the 50mm.

Discussions about aperture (f stop) can get confusing. But here’s a guide that may help with understanding that inverse relationship I was talking about:

wide aperture opening = small aperture value (f/1.4) = shallow depth of field (blurry background) – Good for low light, inside.

narrow aperture opening = large aperture value (f/22) = deep depth of field (focused background) – Good for landscape, plenty of light, outdoors, or using flash.

DTown TV has an episode: Lenses Part 1 that features a number of lenses, including the popular Nikon 20-200mm f/2.8. One of the cool things about DTown TV’s Lenses Part 1 is that they review a number of lenses all in a few minutes, and show you a side-by-side comparison of what it looks like to shoot at 200mm with f/5.6 versus f/2.8. This is a helpful illustration of the nice difference shallow depth of field can make, especially in a portrait.

Don’t have a digital SLR yet? Still want to throw the background out of focus and keep the subject sharp for that professional look? Here’s an article from David Pogue’s New York Times column that explains how to achieve the blurred-background effect, even with a simple pocket camera. Enjoy!

Related blog post: What is Shutter Speed? (discusses how to use longer shutter speeds for blur effect while panning)