Photometric sequences to determine telescopic or binocular limiting magnitude

Yes, wasn't there an enlarged picture, very deep, around M 57
where one could find your scopes limiting magnitude just
by viewing in, and around the Ring? Anyone know where I
can find that picture?
TIA,
Tom W




PrisNo6 wrote:
I understand that there was an article in Sky and Telescope a couple
of years ago recommending star sequences to determine limiting
magnitude. Does anyone have a reference or a partial title I can
search on?

In Roger Clark's book, _Visual Astronomy_, he provides a number of
5-10 arcminute clusters to use to determine limiting magnitude by
observation through your scope. I was looking for some other target
sequences, including for use with binoculars. Any other suggestions
would be appreciated.

- Kurt