How to take a photo with a blurred background

This is one of the basics and preliminary questions when it comes to photography, “How to take a photo with a blurred background?”. The reason is quite simple. A blurred background (bokeh) with the subject in focus makes the photo pleasing to look. Even I rushed to learn this technique when I first got a camera in hand because I thought a blurred background made the photo look “professional”. Now with some knowledge and experience in photography, I want to share some techniques that can help you get a blurry background in your photos. But first, lets understand the basics.

Aperture

Aperture is the opening in the lens through which light enters. Depending on your camera settings, the size of aperture can vary. When the aperture is wide open (let’s say f/1.8), it allows a huge amount of light to enter the camera and in the same time, it can only have a small amount of area (may be a few millimeters) in sharp focus. Anything in front and away from that zone of focus will be blurry.

Now when you reduce the size of the lens’s aperture (let’s say f/11), the amount of light entering the camera will decrease, but this time the camera will be able to have a larger zone of focus (may be a few meters), meaning that the amount of blur will have drastically decreased.

aperture and background blur
Notice that the photos with wider apertures (f/1.8 and f/2.8) have more background blur than the photos with narrower apertures (f/8 and f/11)

Depth of field

While discussing aperture, we came across phrase “zone of focus”. Technically, this zone of focus is named as the depth of field. So, to rephrase what we just learnt in aperture section of this post:

  • When we widen the aperture (e.g. f/1.8), the depth of field decreases (less things in focus i.e. more blur)
  • When we narrow down the aperture (e.g. f/11), the depth of field increases (more things in focus i.e. less blur)

Conclusion

  1. There is an inverse relation between aperture and depth of field in a condition that no other parameters change.
  2. For photos with blurry background, we need to set the aperture of the lens at the wider side.

But, aperture is not the only thing that determines background blur. We need to consider the following parameters as well.

Distance between the subject and the background

For a photo with a blurred background, it is not just enough to have the aperture wide enough. Another basic requirement for a photograph with blurred background is that there should be sufficient distance between the subject and the background. Be sure to maintain at least a few couple of feet (5-6ft for starters) between the subject and the background. Otherwise the background blur will not be prominent.

Distance between the camera and the subject

The amount of background blur is  inversely proportional to the distance between the subject and the camera while all other conditions and settings remain unchanged. What this means is that without changing any of your camera  settings, if you move closer to the subject and take a photo, you will notice that the amount of blur will be more when you are closer to your subject. The amount of blur will be maximum when the distance between the subject and the lens is equal to the “minimum focusing distance” of the lens. The minimum focusing distance is indicated on your lens if you want a reference.

closest focusing distance
Notice that the first image shot at the closest focusing distance has more blurred background than the second photo

However, when you follow this method to increase the amount of background blur, you will notice that your composition will change drastically. So be careful and aware of what you are doing while following this method.

Focal length

Focal length is another critical factor that affects background blur. Basically, as the focal length increases, the lens’s depth of field decreases. This means that the amount of blur will be more as the focal length increases while other conditions and settings remain constant. However, when you zoom in, to maintain a proper composition, you will need to move back.

background blur
Greater the focal length, more the background blur (other conditions and settings remaining the same)

Sensor size

Now this is something that you cannot change via your camera settings. Camera sensor size plays a pivotal role in determining the amount and quality of blurriness in areas that are out of focus. Basically, larger the sensor size, more will be the blur. This is why portraits taken with a phone’s camera does not have that blur effect because of the tiny sensor they have. In contrary, a full frame camera will have a better background blur compared to a photo taken with a phone camera or even with an APSC camera.

Want even more blur? Go for a medium format camera 😉

Summary

After this lengthy discussion to get that beautiful background blur on your photo, let’s summarize it.

  • Set your aperture to the widest setting (f/1.8 or f/2.8 depending on your lens)
  • Maintain a good distance between the subject and the background
  • Zoom in tight and move back to compose your shot
  • If you do not have a zoom lens and if the lens is wide (something like a 16-35mm), you will need to be close to your subject for the maximum blur effect. But, be very wary that being close to the subject with a wide lens will distort the subject and make the photo unflattering

Hope this guide helped you in understanding the theory behind getting a proper background blur in photos. Keep those shutters clicking.

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