Academic Phoenix Plus has some insightful tips to help you modify your Arnold lights by using a light blocker.
Monica from Academic Phoenix Plus covers all the light sources in Arnold along with some tips and tricks for using them. Her latest tutorial focuses on working with an interesting feature called, “light blockers.” You can use this to mask out effects of lights without having entire scenes cluttered by additional geometry!
You can find the Blockers in the light filter section of the attribute editor. Monica’s tutorial shows how to access these elements and what they might be used for, like blocking out unwanted shadows or adding fill lights where needed!