It seems that many are quoting peak whites using the same size window that they did their grayscale and color but that can vary from 2% to 10% which would give you a pretty big swing in quoting peak whites.
I've also seen people quote peak white off of a 10% (or maybe 10.8%) window since it's consider the standard size window.
What's considered the most correct way to do this?
It really comes down to what patterns you are using. Joe Kane uses the 18% ones. THX uses 6.5% ...
And I personally don't care since exact light output doesn't really factor into a calibration. (It's pretty much taught like that as well.)
For the people that review TVs in the magazines, who really knows what methods they use because it certainly isn't standardized. The reviews can be done with no real instrumentation of all types of different test gear ... because different companies make different gear and their patterns vary in size too.
Michael Chen @ The Laser Video Experience ISF/THX/TLV Video Instructor The Video Calibration Education Hub - www.TLVEXP.com