  We discuss the system requirements for obtaining millimagnitude photometric
precision over a wide field using small aperture short focal length telescope
systems, such as are being developed by a number of research groups to search
for transiting extra-solar planets. We describe the Hungarian-made Automated
Telescope (HAT) system which attempts to meet these requirements. The
attainable precision of HAT has been significantly improved by a technique in
which the telescope is made to execute small pointing steps during each
exposure so as to broaden the effective point spread function of the system to
a value more compatible with the pixel size of our CCD detector. Experiments
during a preliminary survey (Spring 2003) of two star fields with the HAT-5
instrument allowed us to optimize the HAT photometric precision using this
method of PSF broadening; in this way have been able to achieve a precision as
good as 2 millimagnitudes on brighter stars. We briefly describe development of
a network of HAT telescopes (HATnet) spaced in longitude.
