... and how the stress moves in:
PHO-to-graph
pho-TO-graph-y, pho-TO-graph-er
pho-to-GRAPH-ic
TRANS-port
trans-PORT-a-tive
trans-port-A-tion
RA-tion-al
ir-RA-tion-al (or IR-rat-ion-al, if being contrasted with 'rational')
ir-ra-tion-AL-it-y
ra-tion-al-is(z)-A-tion
There seem to be rules in there somewhere, but they contain so many exceptions that it's best just to learn them (or let your instincts take over).