Yellow LED Astronomy Flashlights

Back when I had my astronomy-friendly outdoor lighting business, I used to sell yellow-LED flashlights that I bought from Robert D. Mantell in North Hollywood, California, under the trademark Lo-Glo™.

The Houston flood Memorial Day weekend 2015 wiped out the remaining inventory I had and, sadly, these wonderful flashlights are no longer available.

It is not rocket science.  You need to start with a well-made flashlight, replace the regular bulb with a yellow LED and the appropriate current-limiting resistor, and voila!

Yellow may be better than red.  See the article by Robert Dick, “Is Red Light Really Best?”, in the June 2016 issue of Sky & Telescope.

There’s a great business opportunity here.  It wouldn’t take much to make a better astronomy flashlight than what Orion and others sell.  Besides, I have found these yellow-LED flashlights to be most useful for moving around the house after bedtime (such as a bathroom trip) to avoid being exposed to any bright light at night which would affect your night vision and even your circadian rhythm.

If you know of any astronomy-friendly yellow LED flashlights or would like to manufacture some, please post a comment here or contact me directly.

Bob Mantell’s wonderful yellow LED / amber LED astronomy flashlight
These flashlights are also perfect for getting around the house at night without having to turn lights on, the glove box of your car, reading at night, and many other uses as well.

2 thoughts on “Yellow LED Astronomy Flashlights”

  1. I was pleased to find a company that offers a Yellow LED flashlight. in University Heights, Ohio offers a Mini Amber Flashlight, which operates off of the included 9V battery for a cost of $12.95, plus shipping.

    This device connects directly to the terminals of any 9V battery. It has six amber LEDs that are the same color as the single LED in the Lo-Glo. It has an easy-to-use three-position slide switch. Slide to the right, and the middle two LEDs light up. Slide to the left, and all six LEDs light up. Slide to the middle, and it turns off.

    Comparison between the Lo-Glo and the Mini Amber Flashlight

    Even the two-LED setting is brighter than the Lo-Glo, and I find it to be more light than I usually need, but I am an astronomer that has had a lot of practice seeing and navigating with very little light. It would be nice if LowBlueLights would offer an Astronomer’s Edition of this light that has the LED’s operating at about half the brightness. Even better: the ability to “tune” the brightness levels, analogous to a dimmer switch.

    While the Mini Amber Flashlight is quite small, lacks the ergonomic convenience of the Lo-Glo flashlight, and provides more light than I usually want or need, I recommend it for the following reasons:

    1) Easy to use
    2) Well constructed
    3) Provides good illumination
    4) Provides amber light that preserves night vision and does not suppress melatonin production
    5) Inexpensive

  2. Speaking of flashlights, the Rigel Systems Starlite Mini is a great traditional red LED flashlight for astronomy, but I use it so much that I am constantly opening it up to swap out the 9V NiMH battery. It would be so nice to just charge it via USB or AC in between observing sessions and always have full brightness. There is a definite business opportunity here for a new product that I am sure would be very popular!

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