Photography lab held classes (5)

I believe the answer is:

phyla

I'm a little stuck... Click here to teach me more about this clue!

'classes' is the definition.
The answer and definition can be both groups as well as being plural nouns.
Perhaps there's a link between them I don't understand?

'photography lab held' is the wordplay.
'held' says the answer is hidden in the clue.
'PHYLA' is hidden within 'photography lab'.

Can you help me to learn more?

(Other definitions for phyla that I've seen before include "Parts of the kingdom" , "Divisions in botany" , "Classes immediately below those" , "Divisions in the kingdom" , "whole lot of groups?" .)

I've seen this clue in the Sydney Morning Herald.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.