> Off course there is an industry standard. They call it ISO and they even put in on the box.(posted 8426 days ago)My statement regarded any "industry standard" for the calibration of light meters and the reflectance, transmission or luminance used to calibrate them. Not film speed.
> The test is standardize and testers all over the world use it and also publish their results.
Things have changed; the specific developer and development procecure is no longer standardized. Perhaps this is in recognition of the fact that the ISO speed rating for traditional b&w films had very little to do with the reality of what exposure was needed when the film was developed in a "normal" developer to CIs appropriate for pictorial usage.
Actually Ilford followed Kodak's lead in rating film by EI rather than ISO; Kodak never published an ISO rating for TMZ but simply rated it by EI depending on developer used and the CI the film would be developed to.
I think we're actually in agreement overall; when developed to CIs appropriate for most uses b&w films have usually needed more exposure than their ISO ratings indicate, sometimes quite a bit more.