Another consequence of the geometry was that it is not practical to image sources near the equator, or in the south.

An extrapolated boundary, at for which fluence rate is zero, can be determined to establish image sources.

Implement the extrapolated boundary condition by adding an image source of opposite sign above the surface at '.

Galipedia has access to image sources beyond those provided by WikiCommons.

Using an array of image sources fulfills this boundary condition.

The image source does not have to be photographic.

The endoscopic image can be combined with other image sources to provide the surgeon with additional information.

They work best for setups where the image source is placed in the same direction from the screen as the audience.

Most image sources are designed to project a perfectly rectangular image on a flat screen.

This forms a virtual point of origin, so that the image source appears to be an imaginary object somewhere close to the glass.