Can you get blurred background by adjusting aperture size?

Question

Hello there!

I am new to using DSLR camera and I was wondering if it's possible to achieve those photos with smoothly blurred background (like this one: http://farm1.static.flickr.com/102/258269140_69235e841f.jpg)
just by adjusting aperture size? Or am I gonna need a different lens (200mm?)

Thanks!

Answer 1

the three things that will affect your Depth of Field most are
1) aperture size (great depth of field requires small aperture, shallow depth of field or blurred background requires a large aperture)
2) focal length (shorter focal lengh, greater DOF.....longer focal lengh, shallow DOF)
3) distance of camera to subject (greater distance, greater DOF...........shorter distance, shallower DOF)

here's a tutorial on that subject
http://smad.jmu.edu/dof/

Answer 2

Yes, aperture size controls the amount of area in focus, called "depth of field." Thus, by adjusting aperture size, you can control how sharp or blurred the background becomes.

Wider aperture (a smaller number) will give you less depth of field and thus the background is more likely to be blurred, depending upon the subject distance from the camera. If your subject is too far from the camera, the background may be in focus too, a phenomenon known as the "hyperfocal distance" where everything past a certain point ends up with acceptable focus.

A different lens will also affect how much is in focus; generally, a wider lens has more area in apparent focus than a longer telephoto lens. Thus a telephoto lens that has a wide aperture will tend to have blurred backgrounds.

Apart from the blurred backgrounds, there's a phenomenon known as "bokeh" which has many definitions, but essentially refers to how smoothly the background is blurred and how out of focus highlights are handled. A lens with good "bokeh" is craved over a lens that has just a blurry background.

Depending upon your DSLR camera, the best lens for portraits and bokeh is the Nikon 85mm f/1.4 (I'm sure Canon or Pentax has an equivalent lens too, if one of those is your camera). Absolutely creamy bokeh.

So to summarize:
1) yes, adjusting aperture size will blur your background as long as your subject is close enough to you. See term "depth of field" and the calculator below.

2) different lenses affect how much area will be in focus; generally a telephoto is better than a wide angle lens

3) the quality known as bokeh also should be considered when trying to achieve a blurred background.

Answer 3

Depth of Field (DOF) is a result of using a large f-stop such as f2 or f2.8 and a lens with a focal length of 50mm* or more.
The longer the focal length lens you use the shallower the DOF at any f-stop.

Using a wide angle, such as a 10mm or 15mm, it will be almost impossible to achieve an out of focus background - unless you are shooting at the closest focusing distance your lens allows and the background is several feet away**.

EXPO Imaging (expoimaging.net) sells the EXPO Aperture2 Depth of Field Guide. The March 2007 issue of Shutterbug Magazine has a review of it. Go to shutterbug.com and you can read the article. EXPO also offers the ExpoDisc which is useful for setting white balance with mixed lighting sources. You can read its review at shutterbug.com also.

* I have a 58mm f1.2 lens and at its closest focusing distance DOF is paper-thin. It has awesome bokeh (a term used to describe out of focus highlights in the background. Lenses with good bokeh produce creamy indistinct backgrounds).

** Using a Depth of Field Table based on lenses for a 35mm film camera, I find that a 16mm lens (the focal length equivalent of a 10mm lens on your DSLR) yields the following DOF:

Focused at 1' @ f2.8 DOF is 11" to 1' 1"
Focused at infinity @ f2.8 DOF is 9' 4" to infinity

Focused at 1' @ f22 DOF is 9" to 2' 3"
Focused at infinity @ f22 DOF is 1' 5" to infinity

NOTE: The sensor size of your DSLR also plays a role in DOF so the above examples will not apply verbatim to your DSLR.

I have a few examples at flickr.com/photos/8184104@N06

Answer 4

Yes you can. just set your lens to the largest aperture possible, meaning the lowest number. The blurry effect is also more pronounced when the lens is zoomed in. If your new to DSLR, you might want to set the camera to "aperture priority" mode so you can manually select a large aperture and let the camera automatically select the right speed and ISO for you.

Answer 5

From photography and DSLR camera basics right through to advanced techniques used by the professionals, this course will quickly and easily get your photography skills focused! Go here https://tr.im/SFXEJ
By the end of this course you will have developed an instinctive skill-for-life that will enable you to capture truly stunning photos that not only amaze your friends and family... but could also open the doors to a brand new career.

Answer 6

1