Tipping Vendors

how much do you tip vendors?

I found this on the knot.  From what I've read in most guides so far, if your vendor owns his/her own business, there is no need to tip.  So if your photographer is also the owner, you don't have to.  If that's not the case, then that guide from the knot should help.

I think it varies. If they do a terrible job I dont think a tip is even in the picture!