ECP was right that we're all different in our preferences for things, binoculars and exit pupils included.
I was merely sharing my findings that I prefer 6mm exit pupil for daytime use because it helps make it easy to see the view while walking about whereas for nighttime use under brightly-lit skies my eyes prefer smaller exit pupils for a darker sky background. As such, for daytime use I prefer my Nikon EDG 7x42 to my EII 8x30 but for nighttime use I've reached for my Ell 8x30 more often than my EDG 7x42.
For me, a key factor in my differing exit-pupil preferences is that during the day I tend to walk around and for nighttime use I tend to stay put or move very slowly. When staying put, or using binoculars on a tripod, small exit pupils don't pose as much of a challenge for eye positioning compared to when walking about, provided that one takes care in properly setting up the IPD. (If anyone's tried using tiny binoculars, say 8x20 or 10x25, on a rocking boat, you'd know what I am talking about here. There's a reason why the Navy generally prefers the 7x50 format.)
Having said all that, we're all different so there are no absolutes here.
Also, as I've stated multiple times in this thread, my local skies are very well-lit with SQM readings being somewhere around 17 (17.5 at best), probably much worse than most observer's. As such, the findings that I've shared in this thread probably don't apply very well to many observers though I would hope that there are bits here and there that do apply well enough.
Edited by MT4, 23 July 2021 - 07:33 PM.