showing details on video when teaching

Hi Zoom, because of Covid I can't get 6 to 8 people together to teach a class showing students how to tie flies for trout fishing.  My classes have begun but the video quality is poor. No detail or color to the subject which is a close up of a fly being tied in various stages. 
It would appear I am only allowed to go to HD if I have 2 or less participants. 
Is there any upgrade to my subscription I can do? 

Is there any settings I can adjust to help?

Also, I am using an external HD  camera that is in a lighted ring tripod for the tying portion of the class, but I wondered if I can go back and forth between that and my Mac and my iPhone 13 Max?