Red LED Astronomy Flashlight - 670nm Night Vision Light

White light undoes twenty to thirty minutes of dark adaptation in about a second. That is the problem this flashlight solves. A deep red beam at 670 nm lets you find a dropped eyepiece, check a focuser, or read a star chart without resetting your eyes and starting the wait all over again.

The body is aluminum alloy with cooling grooves cut along the barrel. The head zooms from a wide pool of light down to a tighter beam, and a clip on the barrel keeps it in a pocket or on a strap instead of lost in the grass.

Specifications

• Wavelength: 670 nm deep red
• Body: Aluminum alloy with cooling grooves
• Beam: Adjustable zoom, wide to narrow
• Power: One AA battery, not included
• Weight: 2 oz
• Water resistant
• Carry: Pocket clip
• Brand: Johannes Scientific
• Condition: New

Why red light

Your eyes need roughly twenty to thirty minutes in the dark to reach full sensitivity. The rod cells responsible for low-light vision respond far less to long-wavelength red light than to white or blue, so a red beam lets you see what you are doing while leaving most of your dark adaptation intact. It is why observatory floors, star parties, and astrophotography sessions all run on red.

Frequently asked questions

Why a 670 nm red LED instead of a red filter over a white light?
A filtered white light still leaks shorter wavelengths through the filter. A dedicated red LED only emits in the deep red band, so there is nothing to leak.

What battery does it take?
One AA battery, which is not included.

Can I use it for anything besides astronomy?
Yes. Red light is standard for night hunting, wildlife observation, and camping, or anywhere you need to see without blinding the people around you.

Will it hold up to dew and damp?
The aluminum body is water resistant, which covers the dew, damp grass, and light rain that a night session usually involves.

Does it work with a Bahtinov mask?
It pairs well with one. Fitting a mask and dialing in focus is exactly the kind of hands-on task that would otherwise cost you your dark adaptation.