I remember once reading an article about a way to calculate which eyepiece in a telescope would show the most stars. The article was discussing the “majesty factor” that is used to characterize widefield eyepieces. It wasn’t the alder index, but something else that also accounted for differences in TFOV.
I’m thinking about getting a pair of Canon IS binoculars - either the 10x42 or the 15x50. So my question is, which one would produce a view with the highest total star count?
The 10x42 has a 6.5 degree field of view, and a 4.2 exit pupil, but only 10x mag and 42mm of aperture.
The 15x50 has a 30% less field of view at 4.5 degree and 20% smaller exit pupil at 3.3, but it has 50% more magnification at 15x and 20% more aperture at 50m (actually 40% if you measure by area)
Given those tradeoffs, which binocular would produce the view with the highest absolute star count? I know the 15x50 will have the higher alder index, but my impression is that at higher magnification, the distribution of stars would be less dense, so that even though I would be able to see fainter stars, there would be less of then in the narrower field of view.