I have been researching these two lenses for some time now and am still undecided. I will be shooting mostly indoors with this lens taking candids of my kids. My main concerns are will the 40mm shoot and focus well enough in low light situations. Not wildly low light, just your normal indoor one or two lamps on scenario. I have seen plenty of image samples of both and, although mostly subjective, the 40mm seems to have better bokeh. If anybody has any input or experience with either of these lenses it would be greatly appreciated.