Originally posted by Kunzite Class A is correct - watch the video carefully, it's quite revealing.
The 5 axis are not the axis on which the sensor is being moved; they're the axis of the camera movements that can be compensated by the stabilization system. Indeed, those are:
+ camera tilting (Pentax can do that)
+ camera turning (Pentax can do that)
+ vertical camera shift
+ horizontal camera shift
+ camera roll on the optical axis (Pentax can do that)
The sensor's plane always is fixed relative to the camera; there is no sensor tilt in that video.
Camera shift starts being an issue on close distances, otherwise it's pretty much insignificant; but for normal shooting, it's camera tilting/turning that must be corrected for.
The video shows the sensor stationary... But the camera moves. So in relation to the camera the sensor does move, in order to balance out the camera movement. The sensors are probably already all there.
Please show me where Pentax can correct tilting and turning. When using the composition adjustment you can change the position of the sensor. The options are up, down, left and right. I haven't noticed the focus plane change, so it should really be the sensor moving around.
Pentax is using this shifting around (which is probably a lot easier to do than to tilt and turn the sensor) to compensate for tilting and turning as well as shifting the camera around. At long distances just shifting around the sensor is good enough. That is also why the camera needs to know the focal length of the lens in order to correct properly...
Please go here (sorry for the massive link... On my phone, and it's a PDF):
http://www.google.com/url?sa=t&source=web&cd=1&ved=0CCgQFjAA&url=http%3A%2F%2Fc758710.r10.cf2.rackcdn.com%2Ffiles%2Fsupport%2Fmanual%2F1327548737_All_Bodies_Shake_Reduction_012208.pdf&ei=xaXbUpCxLYeJrgeukoCQBA&usg=AFQjCNGoOLtkkDNrxiixRWpfoTT0x9H2hg&sig2=UBSNMZ3ozB9fPZFIHTtMEQ
It's some material from Pentax showing the actual SR system. They have magnets around the sensor, which is mounted in a sort of floating way, and the sensor can be moved left, right, up and down.
Now I can understand the confusion, Olympus says most 2 axis SR systems correct for pitch/tilt and yaw/turning, but that is simply not the way Pentax is doing it. Unless I'm really very wrong here, but I haven't seen anything to make me think so.
http://asia.olympus-imaging.com/products/dslr/em5/feature/04/
Btw. I like to use the SR for video, and there you can see how the SR is struggling. The center can stay stable while the left and right is distorting... simply because the sensor is only shifted around, but you mostly tilt and turn while walking.