Can my brother photograph my wedding as a tourist?

I will be getting married in Guatemala. My brother (a US citizen) is an excellent photographer, and I would love for him to take some photos before and after the wedding (he will be in the best man, so can't photograph the actual service).

I have two related questions:

Can he legally do this as a tourist? Or would this count as work, and require a work visa even though I won't be paying him?

This expats post says that working for free for an organization that typically charges a salary is not permitted (in the US). It doesn't mention whether the same restriction applies to freelance types of work.
Assuming he can do it, can he bring equipment with him as a tourist, or will the fact that he's bringing professional photography equipment^* as a tourist raise red flags at customs and immigration (that he should either be on a work visa, or that he's importing equipment, etc)?

*This would likely include not only his camera--which is normal fare for a tourist--but reflectors, lighting, etc.