580EXII Power scale

Ok a bit lost here. I was always under the impression that the power output scale of the speed light was represented by the actual fraction on the screen i.e. 1/1 full power, 1/2 half power, 1/4 quarter power, 1/16 is 1/16th power and so on to 1/128.

Yesterday came across this video on youtube:
http://www.youtube.com​/watch?v=5ynXTMmx-LA

Jump to 04.41 of the vid.. This guy is saying that 1/16th is half power of the flash, 1/32 is quarter power etc.

Now I am lost... Read the manual of the flash, page 22 where it discusses power output.. still unclear. Please help!

Just because some guy on the internet says so, doesn't make it so. The Canon manual is correct.

It is easy enough to try it for yourself. 1/16 power really is 1/16 power, ie 4 stops down, 1/4 distance for the same ISO, same aperture. If 1/16 was 1/2 power, then the distance would be 71% not 25%.

Thank you!!!! Just what I thought! Just wanted to make sure I wasn't going insane!!!