What's the difference between phonologist and photologist?

Phonologist

Definition:

• (n.) One versed in phonology.

Example Sentences:

• (1) Multivalued features have generally not been permitted on the classificatory level of representation by generative phonologists.
• (2) Phonologists have often held that phonetic 'substance' is more or less unrelated to phonological 'form'.

Photologist

Definition:

• (n.) One who studies or expounds the laws of light.

Example Sentences: