Like Frijj has asked, and you have yet to reply. Was he shooting as favour for a friend? OR was he the official paid photgrapher that the couple has engaged?
If he was shooting as a favour for the couple, and the couple gave him a Ang Bao that was $10, they might as well save it. Cuz it doesn't mean anything. Because as friends or brothers, I still have to give them Ang Bao for well wishes, and just basic ettiquettes.
If he was shooting as an paid photographer, and agreed on $10. That is just plain stupidity.
You have to be clearer on the situation, or else it's hard for us to comment.