I know the 20 mm is faster lens. Since I do not own the 20mm, I have a more practical question. I realized on recent trip that 14-42 is not fast enough in low light conditions during low light situation. eg. Taking family pictures in moderately lit room. I had high percentage of blurry photos without flash requiring me to retake multiple times. In real world can someone compare the shutter speed of the two lenses in low light situation in auto or p mode? How much of the faster shutter speed is gained by the 20mm in same situation? P.S. i know the lighting situation can vary but i would like to know the lens relative to each other when in auto settings are used so all other parameters are the same. Btw I have e-pl1. Taking family pictures in general low lighting is important to me because that is lighting situation I tend to end up in during family gatherings. If this lens helps me get those shots easier then I'll consider buying this lens.