I only read the first link. It’s a good example of the kind of thing Ed wrote about binocular vignetting before he recognized his mistake. In that piece he writes about the vignetted aperture he sees at the back of a binocular when sighting through the objective as the “exit pupil”. In fact, it is the field stop of the eyepiece and what is being vignetted is the outer part of the field, not the outer part of the exit pupil. Almost everywhere in the piece the term “exit pupil” should be replaced with some term like “fov” or "field”. This mistake started sometime in 2004 when Ed did some laser experiments and thought a circle of laser light projected on a wall behind the binocular was a projected image of the exit pupil, when it was actually a projected image of the eyepiece field stop.
This misinterpretation led to some inscrutable “studies” like the one in the link above and a few acrimonious exchanges, both here and at Cloudynights, when several people tried to correct the error. I think Glenn LeDrew finally convinced Ed of his mistake a year or two ago and now most of Ed’s posts on vignetting substitute a term like “fov” in places where he would previously have used “exit pupil”. However, all the earlier posts are still there to confuse the unwary.
Edit: I found this old thread. One of the "acrimonious exchanges" I mentioned above begins with Edz's post #10.
http://www.birdforum.net/showthread.php?t=99435
