Great thread Cal. Here is what I have found over the years.In terms of binos I have owned Bushnells,Stieners,Swaro's and Ziess. To tell the honest truth I could not tell a difference between the Swaro and Ziess they are my top picks. When I bought my Steiners they cost me about 700 dollars but that was back in 89. They blew my 150 dollar Bushnells out of the water. My Steiners were 7x50's and they were no brighter then my Ziess I own now which are 10x45's. In fact the Ziess are probably brighter.
When I am writing this I will tell you I have had several eye issues and my eyes do not work well in low light. So if these binos or scopes are clear and bright to me others should be floored.
With rifle scopes I have definately found the the bigger the objective the better the light transmission. My 6.5x20-56 Leupold lr scope is my brightest
. I have a 3x18-50 Swaro that comes very close to Leupold and if it were a 56 would blow the Leupold out of the water. The difference in tube size I dont think makes a difference. To me the biggest influence in clarity and brightness is glass quality.
One other optic I will mention that I am glad I picked up many years ago is my Lica spotting scope. Before it I had a Bushnell package model and was not really impressed but blamed problems on high magnification. When I got this Lieca let me tell youu my eyes were opened. That was probably 25 years ago and that thing still floors me. The other night we were watching a field for white tails and after legal light that Lieca was still spotting deer at 700yds.
I have now given my two cents and once again great thread.