Quote Originally Posted by Stephen Benskin View Post
There is a distinction between film speed and EI. Film speed involves precision testing to determine a numerical value that represents the sensitivity of the film. The other has more to do with how to personally apply the concept of film speed to exposure. Except for the ISO speed standard, all testing methods are concerned with finding an EI. Perhaps the whole point of my argument is that each has it's own purpose and not to confuse the two.
This may be a decent place to plug my recent "article" listing a series of links to some Kodak and Ilford resources which can be quite useful to inexperienced and experienced workers alike. One of the links is to a short publication from Kodak on ISO vs EI. There are likely a lot of people who get the impression from Zone System books etc that they need to do a speed test because the speed on the box is wrong.