Spoiler alert: Story of the Picture
Observations by the author, on two different ocassions:
It was made after sundown, there was a twilight glow on the distant peaks and clouds. The average light values of the foreground were placed on the "U" of the Weston Master meter; apparently the values of the moon and distant peaks did not lie higher than the "A" of the meter ...[b] Some may consider this photograph a "tour de force" but I think of it as a rather normal photograph of a typical New Mexican landscape. Twilight photography is unfortunately neglected; what may be drab and uninteresting by daylight may assume a magnificent quality in the halflight between sunset and dark....
I could not find my Weston exposure meter! The situation was desperate: the low sun was trailing the edge of clouds in the west, and shadow would soon dim the white crosses ... I suddenly realized that I knew the luminance of the Moon – 250 cd/ft2. Using the Exposure Formula, I placed this value on Zone VII ... Realizing as I released the shutter that I had an unusual photograph which deserved a duplicate negative, I quickly reversed the film holder, but as I pulled the darkslide, the sunlight passed from the white crosses; I was a few seconds too late! The lone negative suddenly became precious.