Keith Tapscott.
Member
Here are the results for Halcyon, Perceptol and D-76. All are sharpened equally.
Lppm resolution is subject to small scanning height errors.
Halcyon appears to be the clear winner for fine grain, in agreement with old timers who considered PPD the finest grain developer.
Halcyon has some downsides (1) May cause allergy, see eg The Film Developing Cookbook 2020 p87. (2) Deposits silver particles and requires frequent filtering of the stock solution. (3) Speed loss cf D-76, lower density.(4) Stains (5) Hard to find ingredients.
The numbers look more clearly defined with the D-76.