Charts for limiting magnitude estimation To find your night's naked eye limiting magnitude there is only one reliable way - the star count method of the International Meteor Organization (IMO). The method is simple, precise and easy to apply, but it has one major drawback: The documentation found on the web is practically useless for field work. That is why we generated our own modified map of star count fields. It is based on the original IMO fields, although we took the freedom of making some selections to increase usability. The map is a handy two-page document you can download for free for non-commercial personal use, print and take out into the field. Clear skies!
PDF with chart of the star count fields
star count fields for NELM limiting magnitude estimation