Originally Posted by Bill Burk
My take-away from the W speed article that these different speed ratings are compared based on how well they correlate to the "Picture Tests".
Then the writer makes an outlandish statement that I will challenge: "It is, of course, too time-consuming to use the print-judgment method."
Of course they were interested in developing a universal standard. For one's own work an EI based on what gives one the best prints is the way to go.