Introduction: Astronomy Flashlight

For certain applications a red lensed flashlight can come in very useful. If you are looking at star charts or trying to get around the woods and want to not ruin your night vision, these are perfect.

This instructable makes one from parts you can find very easily and cheaply.

Step 1: Supplies

For this instructable you will need:
1. LED flashlight, the one i used is from a walgreens, you can get these lights for much less on ebay, about 99 cents.
2. Red Photography Gel, This was free from a photo store down the street they give away sample packs to students.

Step 2: Take Apart Your Flashlight

First you want to take apart your flash light, do this carefully, not all these lights are made to be disassembled.

Step 3: Cut the Gel

Cut the gel into a square that will fit into your lens. Then use the clear plastic from the flashlight to cut a circle the size of your lens.

Step 4: Rebuild Flashlight

Step 5: Results

Once the light is done go test it out, you should be able to see things and still have your night vision when the light turns off. If it seems too bright, you may need a deeper red.

This flashlight will be very useful on your next camping trip!


stephenniall made it!(author)2010-08-02

I need one of these I never thought of this .. I thought of buying a flashlight and replacing the LED with red LEDS .. THis is easier and cheaper . Thanks :D

roseawebs made it!(author)2017-01-18

You can check this best tactical flashlight review. Now a days all flashlight are led. So, no need to extra work and almost all flashlight include with led.

roseawebs made it!(author)2016-03-23

Your idea is great. Very useful if still it get at 99 cent ;)

Dr+Frugal made it!(author)2016-03-09

I made one the exact same way but for a different use.. I used mine as a taillight for my bicycle using conduit hangers.. Here's a link to the Instructable I did for the headlights on my bike using conduit hangers.. (Can't remember if I included the break light in one of the photos)

michaelgc made it!(author)2014-06-09

Great Idea, think I will do this on a smaller edc light that I take camping with me...

curious+youth made it!(author)2012-06-25

i did this. except i couldnt get the photography gels so i used the plastic battery separator thingy that came with the flashlight. glad it was red haha

luvit made it!(author)2010-08-02

this helps me run from the cops. works every time.

Landon+Sullivan made it!(author)2010-09-17


thepaul93 made it!(author)2010-08-03

How will this help you run from the cops?

ryanninjasheep made it!(author)2010-08-02

sure... sure.

frenzy made it!(author)2010-08-02


MACKattacksnipe made it!(author)2010-08-14

i got 2 of these at Harbor Feight for 2.99 *(with coupon)

pdc4770 made it!(author)2010-08-07

With white LEDs the light is turned pink rather than red. That means less protection for night vision. A torch fitted with one of the old incandescent bulbs is better. In Britain, look for Quality Street sweets (I think Americans call them candies?) with red cellophane wrappers that are perfect. Good excuse to eat sweets too.

onrust made it!(author)2010-08-04

Great post. More people should use these.

plugable made it!(author)2010-08-04

Very useful, I have though this project might be more expensive. Thanks for the info!

solarblade90 made it!(author)2010-08-03

This is great! I've been looking everywhere for something like this.

Sephiros made it!(author)2010-08-03

If you were a ninja, you wouldn't have told me, or else I'd already be dead.

Sephiros made it!(author)2010-08-02

And why, pray tell, would you need such a thing in a bathroom?

KellyTheAlien made it!(author)2010-08-02

To aim. :D

Sephiros made it!(author)2010-08-02

I'd imagine that, unless you're a ninja, you'd pee with the lights on. Of course, if you're a ninja, you could see in the dark, and you certainly wouldn't need this instructable.

About This Instructable




Bio: I'm a full stack web developer focusing on security and privacy.
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