>Because the water is constantly moving, capturing the filtered images repeatedly won't work -- you end up capturing different images for RGB. You're right, of

>Because the water is constantly moving, capturing the filtered images repeatedly won't work -- you end up capturing different images for RGB. You're right, of course. But don't forget that the shutter speed was very low on these images. It would have harmed if the shutter speed was high : short exposure time of quickly moving water would have given very different water images for RGB. When exposing longer, motion blur makes the water seem to flow, becoming soft and blurry.