Measure, in Japanese Soku (measure, fathom), is one of the various functions that can be equipped on to the Camera Obscura. This function allows the nearest hostile ghost's health to be displayed while they are within the Capture Circle. The ghost's health appears as a small yellow meter that depletes as damage is dealt. The "measure" function is first seen as an obtainable function in Fatal Frame II: Crimson Butterfly, as the ability to sense the ghost's health was already built into the camera in Fatal Frame.