Aperture is one of those scary words that you hear when you are learning about photography and your eyes probably glazed over. Don’t worry, aperture can be your best friend. Besides being part of the exposure triangle (ISO, shutter speed and aperture) which can help you get a properly exposed image, it is what creates those great blurry backgrounds everyone craves to have in your image.
An aperture is a hole or an opening through which light travels.
When talking about aperture people use the words wide and narrow. If you are shooting with a wide aperture then your aperture is set at a lower number. If you are shooting wide open then your number is as low as the lens goes. If you are shooting with a narrow aperture that means that your aperture is set at a higher number like f/16 or f/22.
wide aperture = low number (f/2)
narrow aperture = high number (f/22)
I think when a lot of people purchase their fancy new DSLR one of the things they want to know is how to get the blurry backgrounds. It’s easier than you may think. There are just a few things you need to do to get that look you want.
A Good Lens
First, a good lens. Unfortunately, most DSLRs come with a kit lens and the aperture only goes as wide as f/3.5. Depending on your image this will not give you the blurry background each time like you may want. I recommend getting the 50mm f/1.8 because it’s an extremely affordable lens plus the aperture goes as wide as f/1.8. You will be able to get great blurry backgrounds.
Second, shoot wide open. Set your aperture to about f/2.8 or lower. If I want a really blurry background I will shoot as wide as f/1.8 or wider depending on my lens. The kicker with shooting this wide is less of your image is in focus (which gives you the blurry background). Since less of your image is in focus you want to make sure you are focusing your focal point on your subject’s eye since that is a part of the image you want to be tack sharp. The focus gets blurry as it fades from your focal point.
This image was taken at f/1.8. Notice the blurry background and the bokeh from the light coming in through the tree.
This image was taken at f/22. You can see that almost every part of the image is in focus.
And another example for you:
Wide Aperture @ f/1.8
Narrow Aperture @ f/16
If you want to create the images where your subject is in focus but the background is blurry remember to set your aperture to a lower number. A higher number means more will be in focus and less of a blurry background. So play with your lens and settings and see what you can create!