Originally posted by Rondec My guess is that Panasonic just does what Pentax does with motion correction, which is replace any areas with movement between frames with the first image.
It's possible that Panasonic in-camera processing use more aggressive motion correction (larger mask radius), then Pentax does. The problem with Pentax MC is that it preserve sharpness quite well, but do a bad job at removing motion. I've played around with gimp, to generate a motion mask. What's limited selectivity between motion areas and non motion areas is pixel noise, aggressive motion reduction also removes details in areas that don't contain any moving parts. I was wondering if Panasonic use a special trick (using more than 4 exposures to reduce noise before computing a motion mask, for instance).
The basic problem of Pentax motion correction, which is also a limitation with RT, is that the noise level of a single exposure is higher than the noise level if the 4 PS composite. Therefore, noise differential prevents to detect motion areas very accurately, there is a tradeoff between preserving details and accuracy of motion detection.
My idea was to do two captures (or more) to knock out the noise: a 4 frames stack using composite average mode in RAW, followed by a 4 frames pixel shift with MC disabled, then difference of the 4 frames stack and 4 frame PS, so that the lower noise of the 4 x stack allows for more precise motion detection. Another idea was to capture two (or more) times 4 frames PS without touching the camera (using my IR remote), and then process each PS with upres to 144Mp TIF or RAW, then use Silkypix 10 (SP10) motion detection feature to eliminate parts than moved. SP10 has a feature that automatically detect if parts of images have moved between frames, and it's possible to export the result as RAW DNG... then post process that RAW like a single exposure RAW file.