I really don't understand how a smaller sensor needs less ISO to achieve equivalence to Full Frame. Shouldn't it need more given the smaller size? How does a bigger sensor at a higher ISO gather equivalent light to a smaller sensor at a smaller ISO? Seems backwards to me? If someone could paraphrase for me, I'd be appreciative! I'm obviously missing understanding something Here is the rough spot in the video (12m 40s) https://www.youtube.com/watch?v=DtDotqLx6nA&list=PLBE338967F8DB7F2A#t=12m40s Thanks!