How Do You Get A Blurry Background On Your Photos ?

 For many people, a blurred background is THE quality feature of a good photo. Often associated with the impression that a particularly good camera was used for this. Especially with portraits.

So it's no wonder that many smartphone manufacturers are now working with software and several cameras per device to simulate this effect. As long as it still looks very artificial, there is only the classic way that I would like to present to you today. You don't need a lot of or expensive equipment for this, if you know how to use your camera.

Why a blurred background makes sense

But first we have to clarify the question of when a blurred background is useful and desirable, and when not. The most important reason is focus. This means the content focus on the motif. This is particularly evident in portraits. The model's eyes are normally the most important image content and should therefore be sharp. If the photo is not taken in front of a monochrome wall but outdoors, a noisy background can quickly distract from the actual subject. A blurry background helps the viewer to concentrate on the right subject - the model. In photography, this compositional stylistic device is called the separation of motif, foreground and background.

If you look around carefully, you will notice that the human eye work very similarly. When reading a book, for example, the background behind the book is also blurred because the eye can only see and focus in the center.

In this portrait, the eyes and face are the most important content and therefore in focus.

4 steps for a blurred background

In order to create a blurred background in the picture, there are three factors that can be influenced when taking a photo: aperture, distance, focal length and sensor size.

1. Open the cover

The most important factor in blurring the background is aperture. If you want to know more about it, you can read my article on the bezel . Here is the short version: The wider the aperture is open, that is, the lower the f-number ( e.g. f3.5 instead of f16 ), the easier it is to get a blurred background.

At f16 the background is slightly blurred, but can still be seen.
( Sigma 50mm Art * , approx. 1m distance)

At aperture f2.0 the background can no longer be seen.

This works particularly well with fixed focal lengths, because these are usually much more powerful and at the same time often cheaper than zoom lenses. A popular lens with a fixed focal length is a 50mm f1.8, which is available at relatively cheap prices from any lens manufacturer. This allows you to open the aperture to f1.8 , which blurs the background very much. However, this only works when the aperture is so wide open if the distance to the subject is correct. And that brings us to point two.

2. Reduce the distance to the subject and enlarge it to the background

The second important factor is your distance to the subject and the distance between the subject and the background. The closer you are to the subject and the further away the subject is from the background, the blurrier the background will be. This is of course easier in nature than in closed rooms. In the sunset portrait above, I was about two meters away from Tine. But there were a few hundred meters between Tine and the houses and trees.

Both the selected aperture and the distance to the subject influence the so-called depth of field. This refers to the part in the picture that is sharp in depth. Everything else (e.g. the foreground or background) is out of focus. To illustrate this a little, I've made a few graphics.

First, we look at the depth of field at 1 meter from the subject. I calculated with a 50mm lens on a full-frame camera.

At aperture f1.4 the depth of field is just 3 cm. Both the wide-open aperture and the small distance to the blurred background contribute here. At 3cm, the tip of the nose and ears are no longer sharp when you focus on the eyes.

With an aperture of f16 and a distance of 1 meter, the depth of field is 38cm. So a head would be almost completely sharp if you focused on the eye.

It becomes interesting when you increase the distance between the camera and the subject to 5 meters. There is the depth of field, which is incidentally also often referred to as depth of field, aperture at f1.4 already 85cm.

At f16, the depth of field is 98.2 meters. If you focused on the eye, a tree about 49 meters behind the subject would still be clearly visible in the image. How do I get to just under 49 meters? That is half of the 98.2 meters depth of field. Exactly 49.1 meters. The other half is in front of the focus point, i.e. for the most part behind the camera.

This effect of greater depth of field at a greater distance can of course also be used quite consciously, especially in landscape photography. So if you want to see as much as possible sharply in a landscape photo, close your aperture and focus on a point further away.

In this f16 landscape photo , most of the image is in focus because I focused on a point some distance away.

Since there are a few other influences on the sharpness, e.g. the resolution of the lens at different apertures or the diffraction blur of closed apertures, my thumbs-up recommendation for landscape photos is around f / 8–11 and a focus point at around 20–30 meters Distance. Better a tad further away than too close. If you want to take a closer look at it, you can read this article on hyperfocal distance.

The aim of this article is exactly the opposite, as blurring a background as possible. To do this, we then need the opposite attitudes: an aperture that is as open as possible and as little distance as possible from the subject.

3. Extend the focal length

Another possibility for more blurring in the background is a longer focal length. The longer the focal length, the smaller the depth of field and therefore the blurrier the background. With the same distance, of course.

Here I have brought you an example. At 24mm, most parts of the image are sharp despite an aperture of f2.0 .

Photographed with the Sigma 24mm Art at f2.0 .

A short time later I took another photo from the same distance, only from the mixer instead of from the gallery. But this time with a focal length of 200mm. Here, the whole stage is no longer in the depth of field, only the singer on whom I have focused. The bass player is already out of the depth of field.

Here I used the Canon 70–200mm with aperture f2.8 .

4. Enlarge the sensor

The last and most expensive way to get a blurry background is to use a camera with a larger sensor. A full-frame camera with the same focal length has less depth of field, e.g. one with an APSC sensor or a cell phone.

The shallow depth of field of a medium format camera, the sensor of which is almost twice as large as that of a full format camera , has a very special look that can be seen in the following picture. Although I used a wide-angle lens and had to close the aperture because of the sun, the sharpness quickly decreases behind Matthias.

Photographed with the 45mm sector on the Mamiya 645

Summary

The good news of this article: Two of the four steps I outlined cost nothing if you already have a camera with the kit lens. You can just move the camera closer to your subject and use the longest focal length you have. If you want more blur in the background, a fast prime lens would be a good investment. And if that's not enough for you, the only way to go is full format or even medium format. However, this will be significantly more expensive.