The blue hour — the twenty to forty minutes after sunset when the sky transitions from orange to deep blue and the ambient light levels drop into the multi-second exposure range — is the landscape photographer’s most repeatable reliable window. The NIKKOR Z 20mm f/1.8 S is the lens that uses it best: wide enough to place a strong foreground against the sky, fast enough to gather usable light at moderate ISOs, and optically clean at the corners where ultrawide lenses frequently degrade.