Introduction: Teach an Old Flashlight a New Trick

By Steve Willingham
About: I'm a husband, a father, an engineer, a maker, a business analyst, an accountant and business leader, (yada, yada, yada ...) and a catalyst for community driven innovation. Greetings and my hats off to the In…

So you wake up at 3 in the morning and you groggily think to yourself “too much beer with the gang last night – I really gotta go”. You get up and stumble into the restroom and dread turning on the light – “Oh no, bright light, arrg, bright light”. There’s got to be another way that’s not so hostile to your sense of ocular decency. Well, some of us use a flashlight, but that can go either way, too bright or not bright enough. But there’s actually a really cool thing you can make that’s drawn from lessons gleaned from the days-gone-by photo processing labs.

Historical sidebar: More than a dozen decades ago it was discovered that certain colors of light would allow a person to see what they were doing in the photo processing lab (the dark room) while not adversely affecting the black & white photo paper being processed. The two main colors of light used were amber and red. And as an added benefit, these colors tended to not leave the person too "flash blind" when the light level changes suddenly. So red lights are still used in certain highly sensitive environments, like airplane cockpits, or submarines. (Readers in the know, tell us more about this.)

Anyway the yellow/amber colored light generally makes a fairly pleasing hue to illuminate an area without assaulting your eyeballs much. In this Instructable I’ll share a super simple way to turn your small flashlight into a nighttime easy-on-the-eyes illuminator. Works great as an ambient bedside light too! (See the pic at the end of the article.)

Step 1: Materials and Tools

  • Flashlight - An inch and a quarter diameter works well. Choose one with a size that works with the next item.
  • Empty amber Rx plastic pill bottle. The type with the screw on cap generally works well. The darker amber the better (experiment). If you use a different type, let us know!
  • Electrical or duct tape (for optional light shield)

Step 2: Remove the Bottle Label

OK, you’ve used the last of the medicine in the pill bottle, right? Well don’t throw that beauty away. We’re going to remove the label and use the bottle as a light filter. There are dozens of approaches to removing a label from a plastic bottle. I use a quick but delicate microwave method.

  1. Fill the plastic bottle with water up to the top of the label.
  2. Microwave for about 50 seconds. Be careful not go too long or you’ll to melt the plastic!
  3. Remove from the microwave and dump out the water. Careful, it’ll be hot.
  4. Now the label glue will be soft and you should be able to cleanly peel it away from the bottle.

Trouble? There’s an Instructable here that uses water without the microwave. And you can look up other ways here.

Step 3: Test the Fit

Just remove the cap and see if the bottle fits over the front of the flashlight. If it fits snugly you’re half way home. If it’s too small, then see if cutting off the neck will allow a better fit. If that doesn’t work, perhaps cutting off the bottom of the bottle will allow just that part to fit in the flashlight lens. If that doesn’t work, you’ll need to acquire a different size flashlight or plastic bottle. In any case, the idea is to make a color filter for your flashlight that completely filters all the light with no light leakage.

I was very lucky, the standard screw cap type Rx bottle fit over my inch and a quarter diameter flashlight perfectly. Whew!

Step 4: To Shield the Bulb or Not to Shield, That Is the Question!

Once you have an amber bottle that fits, decide of you want to shield light from the bulb that may emit peripherally and strike you directly in the eye when you wish it wouldn’t. Bad flashlight, bad. If you need to attenuate the offending glary rays, attach the bottle to the flashlight and examine the light as it passes through and determine how far up the sides of the bottle you want to place your light shield. (Is a light shield protection from a light sabre? Hmmm.) Use electrical tape or duct tape on the side of the bottle to make the light shield. On mine I added about two and a half inches of black electrical tape around the bottle which perfectly eliminated the nasty side splash of light from the LED bulb.

Step 5: Permanent or Removable

Now just decide if you want this neat amber filter to be a permanent part of the flashlight or not. If you’re going permanent, your ol’ friend duct tape should do the job just fine. As for mine, since the fit was so uniformly snug on my flashlight, I chose to keep it removable and therefore versatile.

Tip: Point the amber light up into an existing bedside lamp shade and the room will be graced with a gentle, soft ambient light.

That’s it! I’ve shared this little trinket with several friends and each have been delighted with the results. Please share your experience. Did you have trouble finding a good fit? Do you have alternative plastic filter items?

PS.I was asked how I took the photo at the top of this article because it seemed so well arranged and lit. Actually I used the table top studio in this Instructable (thanks EF).