Cool hand Luke!
David - don't forget, even if the CCD uses less power, there is more data read/writing/processor time due to increased file size with the 50. Not sure if that will have an effect on power consuption.
Kind regards,
Derek
Apparently it is related to the flush system of the CCD which has an effect on power consumption.
But yes, you are quite right - there are many other factors at play. Extending battery life alone has the camera continually turning different processors on and off to eek out as much as possible.
Best,
David