Funny that the Phoenicians, who had a perfectly serviceable F decided to spell it with a P-H. Their F historically represented a hook on the end of a staff and made a sound like a V. Of course in english we haven’t rid ourselfes ov making the two letters interchangeable for the sounds.
Careful not to confuse ‘long s’, ſ, for lowercase f, as many people, and most OCR programs do. Long s often has a lead-in stroke, but never has a crossbar. The character fell out of disuse starting in the late 18th century. Unless you’re typesetting a historical or period work, you may never touch one.
Pedro Leal’s Penna delicately writes our F in a formal calligraphic style.

One Comment
Well that’s because the “Ph” (which derives from the letter “Phi” in the Greek name for the Phoenicians”) is a aspirated labial stop (*P+breathing) and not a fricative (*F)… of course the Phoenicians called themselves Canaanites.