I am in skywatcher group, we travel to Atacama desert... One of the experiments we did was determining maximal visual magnitude. My friend was able to see 8.1

I am in skywatcher group, we travel to Atacama desert... One of the experiments we did was determining maximal visual magnitude. My friend was able to see 8.1 magnitude star with 90% probability. We counted stars in triangles, 2nd person prepared maps and validated results.