this site http://www.go.ednet....o/maglimit.html
tell us how to calculted for telescope but not for binocular;
somebody said for binocular with one eye we can say (ADD?) 0.38
theoretical.
in real world
I can say I see all the Pleiades stark, that is 12 mag in the bad sky of quebec city.
I have 25 x 100 chinise binocular but very big eye relief
excellent for me.
and you, what is your faintest object?

mod note:
Jack, just trying to help out a little here.
edz