Dark Sky Camping
Dark Sky Camping Guidelines
“Less Light is Better; No light is Best.”
There is always light at night, even if there is no moon. The key for safe and enjoyable dark sky camping is to eliminate as much artificial light as possible and to foster an environment where your night vision will not be compromised. When your eyes are fully adapted to the dark, you will be able to see well enough to move round without artificial light and will have access to the awesome wonder of gazing into the endless star-filled skies. The key to sustaining night vision is to limit your eyes’ exposure to artificial light sources.
Understanding Human Night Vision
Three things must happen for the human eye to adapt to night vision: the pupils must open as wide as possible and the light sensing cones and rods in the eye must recalibrate to low light sensitivity. Pupils respond and adapt to low light in a matter of seconds. The cones, our rapid movement and color sensing vision components, can take 10 to 20 minutes to regenerate and reactivate low-light sensing chemicals. The rods, the slow reacting and strongest component for low-light vision can take from 1 to 2 hours to fully regenerate and reactivate the light sensing chemicals for our fullest night vision. Exposure to bright lights, a computer, or phone screen can quickly bleach and deactivate the low-light sensing chemicals necessary for fully night vision. This will reinitiate the process of our eyes adapting to night vision, thereby extending the time required to reach full night vision. The final caveat is that with age, our pupils respond slower, allowing more light into the eye if a bright source is momentary encountered during the required night vision adaption period. This sets back the night vision adaptation process further than younger eyes where rapid pupil reactions provide more protection for night vision.
The Pirate Solution to Sustaining Night Vision
Stories suggests that pirates wore eye patches at sea to retain the night vision in one eye while allowing the other eye to adjust to the bright light of daytime on the ocean. Below decks on ships of the 17th and 18th centuries, there were few or no sources of lighting. Moving from the brilliance of the sun-drenched deck to the darkness of below deck created a situation of dark blindness. For captains and officers who had duties both above and below decks, it was imperative that they could be fully functional in either environment at a moment’s notice. The eye patch assured that one eye would be dark-adapted when exposed to the dim light below deck without the time delay associated with night vision adaptation. An eye patch is not necessary to use this technique for dark sky camping. When you have to look at something brightly lit, simply close one eye to save its night vision adaptation. When you turn the light source off, your closed eye can be opened and it will have retained most of its night vision adaptation. This can be a bit disorienting, as you will experience a sensation of night-blindness in the eye exposed to the light, but you will quickly adjust and will still be able to function in the dark until the exposed light eye readapts to night vision.
Lighting Ideas for Dark Sky Camping
The best scenario for dark sky camping is to set up camp well before the sun sets. This will allow your eyes to slowly adjust to the darkness at the natural pace of falling twilight. If you set up camp in the dark, the light level required for driving and setting up camp will delay the process for your eyes to adapt to the dark until you have turned off all the bright lights. Then your eyes will be hours away from full night vision.
The four simple elements to remember about dark sky camping-
1 If you see a light source, be it a lantern, headlamp, dome light, or flashlight, you will compromise your night vision
2 Use lowest power, “warmest” light sources possible ie. light sources toward the red end of the light spectrum, less than 2700˚ Kelvin)
3 Use shielded light sources that only shine light on what you need to see
4 Only use light when and where you need it. Turn all lights off when they are not being used
Preserving the Dark Sky for Others
As you look out over a dark sky location, unshielded artificial lights will be noticeable from miles away. Courteous dark sky campers do not want to be that annoying light source that will compromise the experience of other campers enjoying the awe and wonder of a dark sky. As you plan for dark sky camping, experiment with portable lighting sources. Lights with variable brightness are a good choice. Ask the sales staff of your favorite outdoor store for ideas and lights that will compatible with the dark sky camping objectives listed above. Low power flashlights and/or headlamps with a red light setting are one of the best options, although shining a red LED light directly into someone’s face is annoying and can set-back their night vision adaptation process. Learn to be headlamp/flashlight aware- think about where your headlamp/flashlight is pointing and turn it off when you do not need it.
Dark Sky Considerations for Vehicle Use
As you drive into a dark sky camp at night, slow down and use low beam lights as you make the final approach. In the camp itself, driving very slowly can make driving with parking lights alone a viable alternative to headlights, if it is safe. Turn the dashboard lights to low or off, especially if you drive a newer vehicle where the dashboard lights turn on every time a door is opened. Turn off the dome lights in your vehicle and use a portable, shielded light to find what you need in the vehicle. Read the vehicle manual to see if you can disable any exterior vehicle light from coming on when you open doors, trunks, or tail gates, this is especially true for cargo lights in the bed of a pickup. Locking vehicles and setting alarms can trigger flashing exterior lights that can compromise night vision. Is locking your vehicle necessary?