Trying to find a flashlight adapter

[AmbulanceDriver]

So long story short, I'm trying to find one of those rubber cup flashlight adapters with the 90 degree piece of glass/lexan/whatever that fits a minimag flashlight.  I used to have one 10+ years ago, but it got lost somewhere during a move.  Long story short, I'm using it to try to improve the light quality going into a prism to demonstrate divergence to my 4 year old.  I've found other bore light type adapters, but they're all on led lights, and those just don't work (found my old incandescent maglight and while I'm getting some divergence, the light quality just isn't as good as I'd like, so I wanna try it with one of those adapters to try to improve the quality of the light and reduce the beam size going into the prism. 

I found one by pelican (90 degree lightbender is what they call it), but I can't find any info on whether or not it will fit on a minimag

[K Frame]

Not seen one of those for a LONG time, and I've not come up with anything via Google...

[Fly320s]

You can buy a new flashlight with the 90 degree head for less than $10, if that suits your purpose.

https://www.google.com/search?q=military+90+degree+flashlight&rlz=1C1CHZL_enUS746US747&oq=military+90+degree+flashlight&aqs=chrome..69i57j35i39l2j0l3.10998j0j7&sourceid=chrome&ie=UTF-8

[K Frame]

Wait a second...

If you want to demonstrate divergence, bring the munchkin in here and start a "Cornbread and Sugar -- Yes or No?"

The kid will see so much divergence he'll be scarred for life.

[230RN]

I'm confozzled as to what you're trying to do.

Most modern flashlights have LEDs.  I guess the spectrum of an LED isn't continuous enough to show what I think you're calling "divergence."

Seems to me an incandescent light would be better.  Or sunlight.

[Scout26]

Just buy the album....

[Hawkmoon]

I think most artificial light sources are too monochromatic to exhibit much divergence through a prism. I think you'll have better results with sunlight. Maybe take a sheet of paper or shirt cardboard and poke a tiny hole in the center to create a narrow beam for the prism.

[Brad Johnson]

I think most artificial light sources are too monochromatic to exhibit much divergence through a prism. I think you'll have better results with sunlight. Maybe take a sheet of paper or shirt cardboard and poke a tiny hole in the center to create a narrow beam for the prism.

Any "white" light source will be mostly full-spectrum, though there may be distinct notches in the spread where certain wavelengths fall out. Actually, that might be a bonus. Give kiddo a extra lesson in sunlight versus artificially produced light. Sunlight / incandescent / fluorescent / LED.

Also, a piece of cardboard or heavy card stock with a hole cut in it the size of the prism face makes a dandy "waveguide". Allows you to more precisely target a particular illumination source.

Finally, get a package of cheap theater lighting gels. Have fun with showing how light absorption works.

Brad

[HankB]

If you're using the prism to separate colors of the spectrum, the proper term is dispersion, not divergence. It occurs because the refractive index of the glass varies with wavelength of the light. The effect works best if you have fairly well collimated light. I've found that the Bell & Howell tac light ("As Seen On TV") actually does a respectable job of collimating the output with the zoom function - about as well as you're going to get for under $10. But of course you'll need to narrow down the input with a slit over the incident prism surface and, ideally, experiment with spacing the source from the prism.

"White" illumination LEDs usually emit in the blue and are coated with a phosphor which will fluoresce with a continnuum of light that appears white to your eye. You can verify that all colors are present by looking at a color chart - if you see all the colors you're supposed to, then all colors are present in the illumination source. Typical "white" LEDs will still have a peak in the blue this makes the light appear "cold" to the eye. Lots of variations on the market.

Here's a diagram that illustrates variations in spectral output of some different sources.

[AmbulanceDriver]

You're right, I meant dispersion, not divergence.  That'll teach me to post after a glass of wine... :D  I've got some LED light sources, but they show some definite gaps in the spectrum.  Which is educational in and of itself.   I have one incandescent mini-mag light, which shows a much fuller spectrum, but the beam quality is... well, messy at best.  I can get an ok spectrum to show up on a wall, but I'm hoping to use something like that fiber optic adapter I posted about to tighten up the beam a little to get a cleaner/stronger spectrum to show up.

[AmbulanceDriver]

and for those wondering what I'm talking about with the mini-mag adapter, this is what it looks like:



Except that one is for a Pelican 1900, and I don't believe it fits onto a mini-mag

[cordex]

and for those wondering what I'm talking about with the mini-mag adapter, this is what it looks like:



Except that one is for a Pelican 1900, and I don't believe it fits onto a mini-mag

This is a cheap single-use kind of application, right?  Why not just buy that $3 adapter and modify the cup if necessary with a knife and gaffers tape to get the desired result?
$6.25 shipped here: https://www.bhphotovideo.com/c/product/984646-REG/pelican_1900_925_001_90_deg_lightbender_for_the.html

[slugcatcher]

I used to see those sold at gunshows for the mini maglight. 

This may work for you.
https://www.ebay.com/itm/Hoppes-BRL1-Bore-Light-Black-Plastic-Housing-Fiber-Optic-Extender-90-Angle/263038267350?epid=2254474383&hash=item3d3e4d6fd6:g:gEAAAOSwiIxaBj8Y

[HeroHog]

The "adapter" on that is an old style spark plug boot for the distributor cap end of the wire.

[AmbulanceDriver]

Eh, I found a pelican 1900 that has an incandescent bulb and the adapter pictured above.  we'll see how it works for the prism.  :)