Perhaps somebody more knowledgeable can calibrate me on this:
In the middle of those pics there’s one of a flight of a dozen Supermarine Spitfires. It looks to me like all of them have two-bladed props. Isn’t it true that these would be a fairly early variant of the Spitfire? Initially they had this two-bladed prop with a Rolls-Royce (Griffon?) engine, but I think they fairly quickly changed that to a 3-bladed prop and a more powerful (Merlin?) Rolls-Royce in it.
Am I right about that?
Generically, two-bladed props are longer and can fly a plane faster (there are exceptions) when level.
Three-bladed props are shorter, giving more ground clearance (essential for operating out of bombed or dirt runways) and faster climbing speeds.