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Whether you are shooting portraits or capturing closeups, one of the best ways to make the photo aesthetically appealing is to eliminate the background distractions and emphasize the main subject by blurring the image background using selective focus techniques. So, what is selective focus in photography?
What Is Selective Focus?
Selective focus is a technique in photography that allows you to have the main subject in focus with the background out of focus and blurred. Generally, selective focus allows you to choose the focus point to isolate the main subject and blur the other elements in the frame.
That means the selective focus is closely related to the depth of field, which refers to how much of a photo can be considered to be in focus. Typically, you will have a shallow depth of field when you use selective focus techniques and a deep depth of field when you have everything in the frame in focus.
Although the quality of the bokeh effect when employing selective focus techniques will vary with the lens’s diaphragm blades and whether you are shooting a moving or stationary subject, you can use the following camera settings to get a background blur.
Use a Wide Aperture
The aperture is the lens’s opening that allows light to reach the camera sensor. The aperture is indicated as a ratio of focal length such as f/4.5 or f/1.4. Usually, a wider aperture results in a shallow depth of field and beautiful bokeh quality.
For instance, an f/1.4 aperture will produce a more pleasing bokeh effect than an f/4.5. However, it’s not advisable to use your lens’s widest aperture as it can affect the sharpness of the main subject.
Instead, use your lens’s sweet spot aperture setting, which is usually 2 to 3 f-stops from the maximum wide aperture. That means you will need to set your lens to the Aperture Priority or manual mode so you can control the aperture.
Use a Telephoto Prime Lens
The lens’s focal length determines the field of view, with longer focal length lenses having a narrower field of view than their shorter focal length counterparts. With a narrower field of view, the image’s light rays tend to be more parallel than when having a wide field of view.
As a result, there is a shallower depth of field when using longer focal lengths than when using shorter ones. On the other hand, prime lenses tend to shoot sharper and crisp photos than their zoom counterparts.
That means you can achieve a better background blur when using a prime telephoto lens than when using a wide-angle zoom lens.
Keep the Background Further From the Subject
Whether your lens features a high-end autofocus system or you are using a manual focus, it can be challenging to focus on the main subject without focusing on the background when the subject and background are close together.
For instance, it’s challenging to focus on a person leaning on a wall without focusing on the wall. The best way to ensure you don’t focus on the background is to increase the subject’s distance to the background.
When to Use Selective Focus Techniques
Since selective focus techniques allow you to focus on a small part of the frame and the rest is blurred, it might be the best photography technique to use in the following situations.
- When you want to improve the aesthetic looks of portraits: Generally, portraits look aesthetically appealing when you have the person’s face sharp and in focus, with the background blurred. The technique can even allow you to isolate the person from the crowd by focusing on the eyes.
- To get rid of background distractions: There are higher chances that the viewers will get distracted by a detailed background and start paying attention to the background elements rather than the main subject. Using selective focus techniques prevents this.
- When you want to cut out the main subject: If you are planning to cut out the main subject using selection tools such as the Photoshop quick selections tool, it’s advisable to shoot with the background blurred as the Photoshop algorithm will be able to more accurately detect and select the main subject.
Frequently Asked Questions
Does the Subject Distance Affect the Depth of Field?
Yes, the subject’s distance affects the depth of field. Placing the camera near the subject results in a narrow depth of field, and placing it further away results in a deep depth of field, making more of the frame to be in focus.
Can I Blur the Background in Photoshop?
Yes, it’s possible to blur the background in Photoshop. Open the image in Photoshop, navigate to Filter, select Blur and then choose Gaussian Blur. You can play around with the slider settings until you get the right amount of background blur.
Applying selective focus techniques in your photos can help emphasize the main subject without distractions from the background elements. For the best results, use a wide aperture telephoto prime lens, with aperture settings 2 to 3 f-stops from the widest aperture.