“Specular Highlight” is easily one of the most misunderstood in all of photography. Traditionally specular highlights are taught to be the brightest part of a photograph.
The baffling thing is that specular highlights aren’t always the brightest part of a photograph.
I was really confused by these highlights. So I looked up “specular” in the dictionary. It’s an adjective (Sorry. Mom was an English teacher) and it’s defined as “having the properties of a mirror.” MIRROR! Wow! Specular means mirror. A specular highlight is a mirror image of the source of light in the subject! That makes total sense.
Photographs are happy to tell you how they were lit. Those secrets lie in the specular highlights and the shadow edges (unless of course someone has been mucking about in Photoshop.)