Roger Hicks
Veteran
You may find the following descriptions of 'old technology' (cubic crystal), 'new technology' (monosize controlled crystal) and chromogenics useful:
http://www.rogerandfrances.com/subscription/choosing bw films.html
Cheers,
R.
http://www.rogerandfrances.com/subscription/choosing bw films.html
Cheers,
R.