[ATM] Difraction Spikes

[Nils Olof Carlin]

Richard,

> Does the spider "throw energy into the spikes", or does it remove  energy? 
> This orthodox misdirsction is starting to annoy.

both, the authorities claim. They (the spiders in this case) will remove (by 
absorption or reflection) as much light as the proportion of aperture they 
cover, but also, by diffraction, misdirect another, similar portion of the 
total light to make it miss its proper place in the Airy disk and form 
spikes. Stan Freberg had a prejudice against spiders, but if you plan to 
illustrate the star of, say, Bethlehem, diffraction spikes are de rigueur.

Nils Olof