Update: I've also published a Hong Kong-specific listing of camera shops and other professional photography resources.
For photographers new to south China, sourcing professional equipment can be difficult. There are small camera shops sprinkled about most large cities (particularly Macau and Hong Kong) but finding suppliers for items more exotic than consumer DSLRs and lenses can be tricky. Many higher-end photo equipment retailers and wholesalers in the area have minimal web resources rendering them nearly impossible to find except through word-of-mouth recommendation.
To aid photographers in Macau, Hong Kong, Shenzhen, Guangzhou and neighboring cities, I will do my best to list my favorite photography equipment shops on this page; I don't aim to make this a complete, exhaustive listing but rather a mix of invaluable and interesting area merchants. Should you know of other area photo equipment merchants worth a visit, please do write.