Board Thread:General Discussion/@comment-43647770-20190828083800

Perception filters (Doctor Who) would have no effect on Sherlock Holmes (Sherlock). This is because of how perception filters work. They make the user a minor detail in the background. For example, if you were looking at a forest, would you notice a specific tree if it was just like all the others? No. You would pass over it, acting as if it didn't exist. You would walk around it, but pay very little attention to it. However, Sherlock, by his very nature, does not "pass over" things. He analyzes them in seconds, able to do things like conclude that a woman was "unhappily married, 10+ years" by glancing at her rings. (There were two rings- one was a wedding ring that was rather tarnished, except on the inside, meaning it was likely taken off quite often. The second ring was a common ten-year anniversary gift.) Sherlock would notice the use of a perception filter because he's just that perceptive. 