Hi Greg. That dpreview post is a fine example of what I was saying - the term "QE" is used, but it doesn't mean a whole lot. Even the author agrees since he says - in the post where he defines his methodolgy - "
The calculated QE is denoted as relative QE, since there might be an multiplicative factor for all QEs. But my opinion is that the range 23 – 40% is quite true for CMOS sensors". I have a lot of trouble taking this seriously when the key ISO measures came from somewhere else (who knows what was measured or how) and the quoted QE figures are
relative, based on an unknown
multiplicative factor that
might apply - and that ultimately it is all the
opinion of the author...
Anyway, I guess you don't see any use for the sensitivity estimation method - fair enough
ref:
http://www.dpreview.com/forums/thread/2750802