Many flashlights, especially penlights do not focus their light effectively, This causes the light to be diffused and the flashlight to be useless. This instructable will show you how to build a cheap and easy reflector so you can focus your flashlight's light more effectively.
First, here is the theory behind the project:
When light is emitted from an incandescent bulb or an LED (less so for an LED) the light spreads out in multiple directions. The purpose of a reflector is to redirect the wasted light and concentrate it, thus making the output of the flashlight brighter.
For more, you can look here:
Step 1: Parts
What you'll need:
Flashlight (can be a penlight or another flashlight)
What you'll use:
Step 2: Mark Your Cuts
If you light was brand new like mine, you may need to open the packaging it came in. Mine was a cheap flashlight from my local drug store (it cost me about $5). Just open up the package with scissors.
Step one of this project is to mark a spot right in the middle of the bottom of your cup. Make sure the mark is the size of your light (in diameter) and centered. Make the mark on the backside of the cup (so it is visible even after you have coated the interior with foil).
Step 3: Make the Reflective Surface
Coat the inside of the cup with foil tape. This will provide the reflective surface for the light to bounce off of. Try to avoid making wrinkles in the tape, because that will cause shadows and ultimately affect your result. Make sure you also cover the bottom of the cup with tape (believe it or not, some light will reflect backwards, and we want it to go forward). You can coat the inside of the cup by cutting strips of tape the length of the cup, and sticking the tape to the walls of the cup.
Step 4: Punch the Hole
Once the interior is coated in foil, punch a hole in the bottom of the cup on the mark we did ealier. Do this from the backside of the cup (So you can see the mark).
Step 5: Finish
Push the head of your flash light through the hole in the cup. Be sure that the bulb or LED part of the light is exposed and contained within the reflector. Then secure it in place with either tape or glue. Turn it on and be astounded by the results! Enjoy!