How many times do you find yourself at a wedding and needing to make portraits in a dark location with no light?  What do you do?  Do you pull out a video light?  Use a flash?  A studio strobe?  A combination of all of the above?  What do you do when you have no time and maybe your backgrounds are terrible or you have no viable option for somewhere to stand and what lens should you be using anyhow and oh no, now you have to decide on settings and meanwhile the clock is ticking away?