For optimal iPhone astrophotography, what specific lunar phase and light pollution conditions must be prioritized to maximize visible star detail and minimize sky glow?

For optimal iPhone astrophotography aimed at maximizing visible star detail and minimizing sky glow, the prioritized lunar phase is the New Moon. The New Moon occurs when the Moon is positioned directly between the Earth and the Sun, causing its illuminated side to face away from Earth. During this phase, the Moon appears almost entirely dark from our perspective, reflecting minimal to no sunlight towards Earth. This absence of bright moonlight is critical because it eliminates natural light pollution, allowing the iPhone camera sensor to capture fainter celestial objects and significantly darkening the overall sky background. Concurrently, the ideal light pollution condition necessitates prioritizing locations classified as Bortle Scale Class 1 or 2. The Bortle Scale is a nine-level classification system that quantifies the darkness of the night sky at a particular location, ranging from Class 1, representing excellent dark-sky sites with virtually no artificial light pollution, to Class 9, indicating inner-city skies. Light pollution refers to the excessive or misdirected artificial light from human sources, such as streetlights and buildings, that brightens the night sky. Selecting a Bortle Class 1 or 2 site ensures that artificial sky glow, which is the diffuse luminance of the night sky caused by scattered light from ground-based sources, is minimized. With both the complete absence of moonlight and the substantial reduction of artificial light pollution, the sky becomes as dark as possible. This dark sky maximizes the contrast between distant stars and the background, enabling the iPhone's computational photography to detect and render a greater number of individual stars, thereby maximizing visible star detail, and inherently minimizing overall sky glow from both natural and artificial sources.