You may blur a background by selecting a background and Lens Blur filter. However, the best way to blur a background is using Alpha Channel plus Lens Blur Filter. Here is how.
- With the image open, create an Alpha Channel in Channel panel.
![](http://www.quicksetupguide.com/blog/wp-content/uploads/2020/04/image-39-1024x574.png)
2. Still highlight Alpha 1. Click Radiant Tool to create Linear Gradient from the right to center.
![](http://www.quicksetupguide.com/blog/wp-content/uploads/2020/04/Capture2-1024x538.jpg)
3. Highlight all Channels except Alpha 1. Then go to Filter>Blur>Lens Blur. Select Alpha 1 channel. Check Inverse (because we blur starts at right eye). Adjust Radial, Blur Focus distance and more. Check and uncheck the Review to compare before and after.
![](http://www.quicksetupguide.com/blog/wp-content/uploads/2020/04/Capture3-1024x561.jpg)
4. Click OK to complete it.