In general, good observatory sites are at high altitude, with clear skies and a stable atmosphere. more specifically, different site characteristics are important for different applications. some of the things that matter include: clear sky fraction: how often the atmosphere is non-cloudy median seeing humidity temperature isoplanatic patch size wind speed light pollution considering those characteristics, briefly explain which are likely to be most important for the following observations, and why? a) wide field imaging in visible light b) adaptive optics imaging in the near-infrared ~1 um c) mid-infrared (10um) imaging