More likely it is both factors at the same time; I think that if you downsample RX100 images to 12 MP, it still has a disadvantage in real camera shake/ IS performance compared to a camera like LX7.BertIverson wrote:
Or because the RX100 has 20MP and slight movements can be more easily seen when pixel level viewing. That's my theory anyways. --John TF wrote:
... and I'm almost certain that's a consequence of its small size. One advantage of the bigger, heavier models is it's easier to hold them steady. "
As part of this is related to the mechanics of the camera, IS gain likely to vary depending on several settings (first of all shutter time). When you add things up it is surprising if there is any lowlight advantage left for RX100 (3x larger sensor), compared to LX7 (brighter lens, better optics wide open, better IS).