There is a big difference in bitrates in the different color modes. Here are the results of some tests I did (I gathered the bitrate info from each file's properties, as reported by Windows): 3840 x 2160 25fps gorgeous 50mb/s 3840 x 2160 25fps natural 42mb/s 3840 x 2160 25fps raw 26mb/s 1920 x 1080 50fps gorgeous 16mb/s 1920 x 1080 50fps natural 10mb/s 1920 x 1080 50fps raw 6mb/s 1920 x 1080 25fps gorgeous 8mb/s 1920 x 1080 25fps natural 4mb/s 1920 x 1080 25fps raw 3mb/s Before I did the test, I thought that the raw setting would be best, as it doesn't seem to have much if any sharpening. Raw would have seemed to be the go-to setting for those wanting the best image. Saturation, contrast and sharpening can be added in post. But it only has half the bitrate as gorgeous! Why can this be? More saturated color doesn't necessarily mean more bits, neither does more contrast. Maybe the sharpened image is harder to compress? Gorgeous looks pretty good, but is over-sharpened to my eyes. If only the sharnening could be dialed down separately. The other thing I don't get is the much lower bitrate for 1080 25p. It should be 1/4 that of 3840 25p, but it is much less than that.