Re: Vignetting due to pupil aberration

On Apr 15, 4:37 pm, Phil Hobbs <pcdhSpamMeSensel...@xxxxxxxxxxxx>
wrote:
Helpful person wrote:

<snip>

Inward coma of the pupil can theoretically be used to get more light
through the system.  However, I have never seen a practical
application of this.

Interesting.  This is basically reducing the anamorphic magnification of
  pencils near the edge of the pupil, to reduce that ugly cos**4
rolloff, is that right?

Cheers,

Phil Hobbs

Not really (if I understand your comment). Imagine the diffraction
pattern from coma, with the principal ray just outside the pupil
aperture. Then for inward coma the fan will spred towards the axis
and hence let more light through. As I said, I can't imagine any
practical example of this.
.