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!