Group: Night

Given the number of groups for sunsets, sunrises, dawn light, and dusk, it may help if we consider what is meant by "night".

Beginning of morning astronomical twilight:
Is defined as the instant in the morning, when the centre of the Sun is at a depression angle of eighteen degrees (18°) below an ideal horizon. At this time the illumination due to scattered light from the Sun is less than that from starlight and other natural light sources in the sky.
Ending of evening astronomical twilight
Is defined as the instant in the evening, when the centre of the Sun is at a depression angle of eighteen degrees (18°) below an ideal horizon. At this time the illumination due to scattered light from the Sun is less than that from starlight and other natural light sources in the sky.

May I suggest that images taken when starlight/moonlight/street provide more light than the sun's reflected rays from below the horizon, would be valid for inclusion, but that the most beautiful sunsets with the sun already below the horizon, do not fall within the definition for inclusion in this Group.

Does anyone who participates in this Group have strong opinions one way or the other on this suggested guideline? I propose it in an attempt to clarify what should be considered as "Night" Images...

Night images which are so under-exposed as to be almost entirely black, without a hint of what the subject matter is, would be hard-pressed to be included.