  We present a perturbative calculation of baryon pair production in two-photon
collisions, $\gamma \gamma \to B \bar{B}$, in which baryons are treated as
quark-diquark systems. Our approach accounts for constituent mass effects in a
systematic way. Taking the diquark-model parameters from foregoing studies of
other electron- and photon-induced baryonic reactions, our results agree well
with the most recent large momentum-transfer data for the $p\bar{p}$,
$\Lambda\bar{\Lambda}$, and $\Sigma^0\bar{\Sigma}^0$ channels.
