I've got a wedding shoot in ten days and I'm panicking because my kit isn't wide enough for this tiny venue. Spent all night looking at the RF 15-35mm f2.8 and the 14-35mm f4 and I'm just stuck. Some say the f4 is sharper at the edges but then my logic was that I'm gonna need that f2.8 for the low light inside this old church. But then I read the 14-35 has way more distortion that the camera fixes automatically? I have about $2200 to spend and need to order it tonight so it arrives in time. Is the extra stop of light worth the extra weight and cash for indoor shots?...