I started this project with no background knowledge on the subject. I selected the man on a hit facing the mountains because I thought it would provide the opportunity to show an increasing scale of blur from the close town to the hills beyond that to finally the mountains beyond that.
I created a selection of the man and saved it. From there I created a gradient layer depth map to establish the gradual blurring of the background elements as we move away from the man. I then selected the man again and set him as 100% in focus:
Below is the finished product:
I kept the layers for this project extremely simple. I duplicated the original layer so I could work non-destructively:
After struggling with some unwanted artifacts while applying the lens blur filter I started looking around for better methods.
I found a video that provided a more realistic method of applying the blur. It is a lot more time-intensive but I think the end results would be worth the efforts. I, however, did not have the time to redo the project implementing the more refined techniques. I would suggest a watch if you’re looking to polish this skill: