Page 167 - Photoshop for Lightroom Users – Scott Kelby 2nd Edition

Step Four:
Keep clicking on the image to add more pins. Once I had a few more in place, I felt the background looked too blurry, so I clicked on each of those pins
and lowered the Blur amounts to around 175. I also moved the pin on her jacket over to the right a little (as shown here), so that there was less blur on her
arm and shoulder. Another thing I love about using Field Blur is that you can move a pin outside the image area, out onto the canvas area, so you can get
just the edge of the effect in the image (as I’ve done here, bottom right). By the way, we’ve been using the Blur slider here, but you can also control the
amount of blur by clicking on that ring around an active pin and dragging around the ring. As you drag, the ring turns gray to show you how far you’ve
gone, and the actual amount of blur appears in a little pop-up display at the top of the ring.