RE: ATM Baffling at the secondary

["Arjan te Marvelde (ELN)" <Arjan.te.Marvelde@eln.ericsson.se>]

Marcus,

Have you also considered thermal effects? The baffle may cool well below ambient temperature, which causes the formation of a boundary layer of cold air. 
This boundary would make the baffle seem thicker optically than its mechanical dimensions suggest.
Maybe the choice of material can minimize this effect.

/Arjan te Marvelde

: Optically, having a baffle at the secondary introduces another element in
: the light path causing diffraction. As long as the baffle is seen edge on
: (which is the case for on-axis stars), this should not add any significant
: diffraction. In fact, if the baffle coincides with the spider vanes there
: should be no additional diffraction effects.

: There are two exceptions to this: