Quote Originally Posted by Photo Engineer View Post
A number of years ago, Herb Wilgus at Kodak came up with this chart. It was used later by Bruce Kahn for his course at RIT. Bruce has given me his permission to use this chart.

I was one of the last people to 'interview' Herb for the emulsoin modeling and scaling software before he died of cancer in the 80s. He was a great guy and a great researcher.

Here it is, finally! Thanks to Herb and Bruce.

This chart taken with my other posts will enable anyone to predict the grain shape of any precipitation of AgBr. Of course there are charts for Chloride and Iodide, as well as mixed crystals. This is a key to the model we used and only works for double run (double jet) emulsions which are made under feedback control.

For those who ask about the other charts, I ain't tellin'!!!!!

For emulsions made using a single run of silver nitrate into salt, you get a mix of all possible shapes and these are K grains (klunkers, not Kodak).


I do not have a background in chemistry, but I'm trying to learn.

Is this chart showing the shape of the crystals when the film is manufactured, or after development? If it is after development, is the scale on the chart the PH level of the developer? Is this chart for bromide emulsions?

I apolagize for being so clueless about the technical aspects of all this and asking stupid questions.