About

How to read a value

Plain

Read from the file, or computed exactly from it. An ISO, an exposure, a twilight time. Presented as fact because it is one.

Dotted underline

Model output from an external source, shown with that source. A 3 km weather analysis is not a measurement taken at the tripod.

Marked “estimated”

Derived through a model with real uncertainty. Always a range, never a single number.

Italic

Written by a person — a place name, a note. The author’s voice.

“Not available”

Said out loud rather than left blank. A blank cell reads as zero, which is the single most common way an honest system becomes dishonest.

What is deliberately not here

Exact locations. Every photograph in this archive was taken by one person, so the coordinate set is a trace of one person’s own movements — where they go, when, and that they were there at night. Publishing exact coordinates of quiet dark-sky sites is also how those places stop being quiet.

So places appear as named areas, astronomy is rounded to a tenth of a degree, times are published to the minute, elevations as bands, and bearings as compass sectors. Each of those would otherwise invert back toward a location. An unpublished place can be published tomorrow; a published one cannot be recalled.

Also absent: any claim about what the sky was actually like. The atmosphere here is reconstructed from models that never observed the site. The photograph is the only evidence — which is precisely what makes it worth keeping.