A while back, I wrote a post about configuring your Wacom tablet for Lightroom and Photoshop. In it, I covered mapping the pen buttons to control your brush size, but there is one other setting that I wanted to mention that specifically affects those running dual monitors.
What I was finding was that my pen was tracking across both screens even though I was using Lightroom on one screen. That meant that my pen was traveling double the distance, meaning that my fine control was limited, and that my pointer would leave Lightroom.
To correct for this, I discovered that I could tell my tablet to only work on one of my monitors or even only in a section of a monitor. To get started, I pulled up my Wacom tablet preferences.
Under Tracking, find the Pen Mode Mapping button and click it to bring up the mapping options.
The Screen Area options allow you to specify whether you want the tablet to track across all of your screens, a specific monitor, or a portion of a screen. By default, the workspace on my tablet was mapped to both screens. Since I usually use my second monitor to edit, I set my screen area to my second monitor. The configuration now shows that the workspace on my tablet maps to the entire 2nd screen, not across both monitors.
Now with Lightroom on my second monitor, using my tablet will keep the pen on the same monitor and give me better control. If I wanted to, I could create a finer mapping using the Portion option of the screen area and just map over the develop module, but I like to still click the adjustment brush options with my pen so simply limiting it to a screen is enough for my workflow.