There are about 70 years inbetween.How do FX-39 and Rodinal compare?
Both developers are similar but FX-39 yields more speed utilisation and gives more equalizing "power" at a given speed.
You can achieve either one also with Rodinal but not simultaniously (special development methods excluded).
Basically Rodinal is closer to a "raw" developing substance and FX-39 is more of a tweaked formula.
Either one has itīs advantages/disadvantages.
Does this make sense to you?