We hear of dark vision or night vision and think Navy Seals, or at least I do. But what does it mean when we’re talking about telescopes?
Night Vision is the ability for something to see in the dark without a light source. Night Vision with telescopes is referring to letting the human eye adjust to seeing its best without a light source. It takes up to 45 minutes for an adult human to see their best at night. Visioning through a telescope is seeing faint lights in the sky. Allowing your vision to adjust and have their maximum dark vision enhances what you can see at night through your telescope.
How do I get Dark Vision
Avoid Light! Neighbors may think you have become a vampire or part of the Zombie Apocalypse, but who cares, you want to see it all of the cosmos you can. It will take 30 to 45 minutes for your eyes to adjust to the darkness, allowing you the ability to see things more clearly in the dark. After your eyes have adjusted, stay in the dark. Avoid going back inside, or even near the windows of the house that have lights on.
Of course, you need to be away from ambient light as well. If you live in the city or suburbs, you may want to plan a destination like the highest rooftop, or an open field. Even the full Moon will give too much light to allow you to see much in deep space.
What takes your Dark Vision Away
The light will take away your dark vision. Your eyes only need about 5 to 7 minutes to adjust to the light. When you come back outside in the dark after that, your eyes will need another 30 to 45 minutes to adjust back to the dark again. Mostly blue and white light rob your night vision. Red light tends not to affect your night vision as drastically as let’s say blue light does. The main reason is that red light is at a longer wavelength and our eyes are not as sensitive to long wavelengths light. This is why they make red LED flashlights. I found that using this still can be too bright, and by putting some masking tape over the end will reduce it down.
How Can I See and Keep My Dark Vision
Get a red flashlight. This is so that you will still have light when you need it to see objects on your viewing area. For example, it may be challenging to set up your telescope on its mounting while in complete darkness. This is the one I got to use for my astronomy use. It is from Amazon, and it can zoom which kind of gives a brightness or dimming effect to the light. Because of the focusing, the light to a narrow beam makes small brighter areas, and the widening dims the light over a broader area. The flashlight should have the red color light because it does not have the same effect on your eyes as blue or white light does as mentioned above.
Can I Use Any Kind of Light to See With?
If a red LED flashlight is not available, you can still use a regular flashlight, just cover it with red cellophane or red paper. We have a local convenient store whose logo is red and yellow. Once, when I forgot my red LED flashlight I bought some snacks at that convenient store, and took the logo area of the plastic bag and using a rubber band (actually a zip tie is what I had available to use) to keep the red part of the logo over the lens where the light comes out. If it is too bright, double over the logo part for a double layer.
What about my Cell Phone Universe Apps?
You should try and avoid cell phone usage while having a dark vision established. The bright background of the LCD will reduce your ability to see. Even the universe apps like “Sky View” are reasonably low in light, but having your phones Facebook notifications or your Mom calls at the wrong time could mean you have to wait another ½ hour or so to get your dark vision back. I suggest using the programs up front to get orientated and then once set up, get your seat, coffee, and extra clothing ready and organized. Shut your phone off.
What if I have to use the Bathroom?
Well, as my Mom always said: “Why didn’t you go before we left the house.” The same kind of thing applies here. Try and go before you start. If you find yourself prancing about, you can use your red flashlight and find your way inside without turning on any lights. If you are alone in a field, remember to pack some TP? I have heard of dedicated astronomers having a bucket with a lid they dealt with after their viewing time. If you do not like any of these ideals, better go easy on the coffee and drinks. Dress extra warm instead of downing hot coffee or Cocoa.
I thank you for taking the time to read the post and hope you have enjoyed it. I recommend this article for more tips and tricks with our “ ## Quick Tips To Improve Your Telescope Viewing.” If you liked this article, you might also want to look at the following.