{\bf Figure 2:} Here is illustrated the meaning of the variables in the 2-point
correlation function $C_\gamma$, $C_{\gamma\kappa}$, and $C_{\gamma\omega}$.
The thick solid line represents the geodesic connecting the two points on the
celestial sphere in question, $\hatbfn$ and $\hatbfn'$, whose length is
$\vartheta$.  The thin solid line at $\hatbfn$ gives the orientation of the
component of the shear that is being correlated, which is rotated $\varphi$
from the direction of the geodesic.  For the shear-shear correlation function,
$C_\gamma$, we also need the orientation of the component of the shear at
$\hatbfn'$ which is given by $\varphi'$.  The handedness of the coordinate
system is important $C_{\gamma\omega}$ since it changes sign if
$\varphi\rightarrow-\varphi$.  The rotation of $\varphi$ is to the right in a
right-handed coordinate system. Note that the usual spherical polar
coordinates, $(\theta,\phi)$ are usually left-handed on the sky since we view
the celestial sphere from the {\it inside}.