Quote Originally Posted by Ian Grant View Post
... Perhaps a simpler explanation is that Ferricyanide on it's own attacks the smaller grains first, that's why it's used with or without bromide for split toning, but with Thiosulphate added Farmers Reducers attacks the larger "black" grains as well at the same time. ...

At first, I thought this made sense, but after doing a test last night, I'm starting to doubt it. I compared the two methods on two identical step-tablet prints, and there is absolutely no visible difference. I'll take some densitometer measurements as soon as I get to it. Maybe that will show a difference.