Quote Originally Posted by markbarendt View Post
I have come to belive that true-underexposures are almost always caused by "us". It is caused by outright mistakes in setting the camera, poor metering technique, a lack of understanding of what the meter is saying, and or in trying to cheat to avoid camera support or flash when it is clearly needed.

"We" are the wild card, not the film. I think it is actually almost impossible to get an underexposure caused by the film ISO rating. Ilford, Kodak, and Fuji are very good at their jobs, their films are well made and consistent and as best I can tell work extremely well and deliver exactly what they advertise.
Mark, that is why I suggest using the ISO speed as a starting point to determine the photographer's personal EI. Most pop testing methods have too many questionable elements that any true accuracy is impossible. All that they can really offer is a way to determine a personal EI. This is what most photographers really need, which is fine if they understand this. What I find troubling is when photographers question the legitimacy of the ISO standards based only on an understanding of a questionable "pop" methodology.

Since obtaining a personal EI is the goal for most photographers, why then waste the time with a convoluted testing method. Shoot some negative as determine how you tend to exposure. But first, determine your processing.