The contribution of city lights and other artificial lighting to the brightness of the night sky at Mauna Kea can have an effect on the quality of astronomy done from the summit. By and large, communities on the Big Island (encouraged by a local lighting ordinance) have very good outdoor lighting, astronomically speaking. This page was created to bring to light (so to speak) the various light sources visible from the summit of Mauna Kea.
The main component of this page is a multi-image mosaic of the island as photographed from the Canada-France-Hawaii Telescope. With it, we can get a fair graphical estimation of the location and composition of light sources on Hawai'i and neighboring islands.
There are 17 images in the two strips of the night view of the island as seen from the catwalk of the Canada-France-Hawaii Telescope. Most were taken during time when the Moon was not in the sky. The remaining two (that including the IRTF dome, and that showing moonset) were taken during times of bright moonlight. The one showing IRTF has been artificially dimmed. The image of the Mauna Loa lidar was underexposed and has had its contrast enhanced to show its position in the night sky. Eleven of the 17 images were taken with a small diffraction grating mounted to the front of the camera lens. This allows identification of the varying sources of light below the mountain. The diffracted spectra of several bright stars and planets are also visible (the direct images of some of which are out of the field of view).
I used ASA 200 Kodak 35mm print film. Most images are about 20 minutes exposure time with a Nikon 50mm f/1.8 lens. The negatives were scanned to produce this combined image.