  The lamppost model is often used to describe the X-ray source geometry in
AGN, where an infinitesimal point source is located on the black hole spin
axis. This is especially invoked for Narrow Line Seyfert 1 (NLS1) galaxies,
where an extremely broad iron line seen in episodes of low X-ray flux can both
be explained by extremely strong relativistic effects as the source approaches
the black hole horizon. The most extreme spectrum seen from the NLS1 1H0707-495
requires that the source is less than 1Rg above the event horizon in this
geometry. However, the source must also be large enough to intercept sufficient
seed photons from the disk to make the hard X-ray Compton continuum which
produces the observed iron line/reflected spectrum. We use a fully relativistic
ray tracing code to show that this implies that the source must be
substantially larger than 1Rg in 1H0707-495 if the disk is the source of seed
photons. Hence the source cannot fit as close as 1Rg to the horizon, so the
observed spectrum and variability are not formed purely by effects of strong
gravity but probably also by changes in corona and inner accretion flow
geometry.
