The Kelling Heath sky camps are the premier UK and probably European star parties. Over the years they have got bigger and last longer as observers seek dark and clear skies. All observers are welcome, from novice to experienced, and whether they are visual or imaging.
Kelling Heath has worked hard to maintain a dark environment on the site, and we must make sure we make the most of it.
Our eyes take at least 30 minutes to dark adapt. It is a complicated process involving the brain, retina and iris. How far the eyes dark adapt depends critically on the light levels the eye can see around us. If there are lights around us, then the eye will stop dark adapting when enough can be seen to get by. So, to fully dark adapt to the maximum possible, visual observers need effectively a complete absence of lights.
What about red lights you are thinking! Dim red lights are seen by the cones in our retina which we don’t use for visual observations of faint objects. So, they are OK. Bright red lights however do affect the iris, the brain and to some extent the dark adaptation chemistry in the retina. Hence bright red lights can destroy dark adaptation.
Exposure to white or bright red light can destroy dark adaptation in seconds, which can take at least 30 minutes to fully recover.
Attendees who are imaging will spend a lot of their time closely studying computer screens to check progress and quality of their images. Any dark adaption will inevitably be lost. Consequently, doing other tasks (adjusting equipment, going to the toilets, etc) will require a much brighter torch.
Thus, it seems that visual and imaging observers might not be happy neighbours. Many star parties have resolved this issue by segregation. Most of us have our favourite pitches at Kelling and we do not want to have to go down this route. Let’s all adopt the best of star party lights etiquette and work together ….
No car interior or boot lights on after sunset.
Only RED torches are to be used at night with light facing down.
Do not point torches or head torches towards other observers, even in the distance.
Lights inside tents and awnings to be red and not too bright.
Shield computer screens if outside.
Ideally use only red lights inside caravans or motorhomes. If not, ensure there is no white light visible from outside and turn lights off when opening the door.
Call “lights in 3 seconds” if a bright light is unavoidable.