Quote Originally Posted by Lachlan Young View Post
Just out of interest, why were active gelatins phased out?


They were too variable and uncontrollable. In fact, EK was almost ruined by the famous (infamous) story of cattle eating mustard which made the gelatin extremely active and fogged the film. It was only then that Mees et. al. discovered that it was the allyl thiourea in the gelatin that caused the actual sensitivity increase in emulsions during making.

The use of sulfur compounds and inactive (intert oxidized) gelatins are what ushered in the modern range of photo products.