Moonlight filter on Incandescent flashlights

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i7r7

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I was using a light microscope the other day and I realised that the light source has a yellow-orange tint but the light reaching the slide is pure white. After investigating the apparatus, I found that there is a blue colored filter below the apeture. I removed the blue (moonlight) lens and used it on my Surefire. The light is finally perfect... focused, bright and pure white (no rhyme intended... seriously, it was a fluke).

Sure, the output is clearly less than the usual 120 lumens but with such a beautiful white light, I'm not complaining. The lens happens to be exactly the same diameter as the bezel on my Surefire, so all I do is stick it down with some tape.

I'm sure if anyone else wants to convert their incandescent to the pure white goodness of LEDs, I'm sure you can source out one of these filters from a microscope retailer.

imgp2149.jpg

Inova on left, Surefire G2/P61 on right

imgp2150.jpg

Inova on left, Surefire G2/P61 with moonlight filter on right

imgp2153.jpg

The moonlight lens

Jeff
 
Nice, good discovery. There's a big difference between those two pics. I'll be looking into this. Thanks.
 
Correct me if I'm wrong but the lens filters out some of the non-blue light but allows all of the blue light through. That's why the lens is blue. Considering that incandescents are more yellow-orange than other colors, the lens evens out the intensities of the spectrum.

Jeff
 
ya, i like White Lights, those found in HID lights.. how can i get 1? how much why it cost? what is the Lens Material? Pyrex?
 
Umm... I got my lens from a Olympus microscope so it cost nothing. If you want to get one, find a retailer that has spare parts for microscopes. If not, try eBay.

I'm not sure if it's pyrex or not but it's definately NOT plastic. It has that high pitched noise when I tap it, it has a glass-ish feel to it. The lens definately reduces the lumens emitted, I don't have an easy way of measuring but you can see in the beamshots compared to my Inova X5t.

Jeff
 
You could also probably use a photographic 80A or 80B filter. These should be available from camera shops and photo supply stores in a variety of sizes and materials (glass, gelatine, plastic, etc.)

The 80A and 80B filters are for balancing daylight film to Tungsten and Quartz lighting.
 
Whoops.

Either a Sky1A or a UV filter protects the front of all my lenses. Nether of them did much of anything.

In my filter pouch were 812 and Polarizers to fit my various lenses. An 812 made my SNII a bit warmer, but took away from overall brightness. Not a trade I'm willing to make.

I find Writeright to be the best possible addition to a flashlight lense! This of course if you don't have any Acrylite:

http://www.candlepowerforums.com/ubbthreads/showflat.php?Cat=&Board=UBB8&Number=317597&Forum=,,,All_Forums,,,&Words=Acrylite&Searchpage=3&Limit=25&Main=317597&Search=true&where=sub&Name=&daterange=1&newerval=1&newertype=y&olderval=&oldertype=&bodyprev=#Post317597

Sorry I can't make a shorter link (or a link that works HINT HINT!), but I'm on an OLD 'puter that don't jump through hoops!
 
Interesting...in railroad signals (for trains - not crossing warning systems), we use combinations of red, flashing red, yellow, flashing yellow, green & "lunar" (white).

These different colors & combinations of them "tell" the engineer to stop, proceed, prepare to stop, diverging route ahead, etc...

The "lunar" is created by a blue lens in front of an incandescent bulb that indeed renders the "white" signal to the engineer...same as your results here, but of course on a larger scale!
 
[ QUOTE ]
PlayboyJoeShmoe said:
...Sorry I can't make a shorter link (or a link that works HINT HINT!), but I'm on an OLD 'puter that don't jump through hoops!

[/ QUOTE ]

You mean like this?

/ubbthreads/images/graemlins/grin.gif

Aloha, iG
 
Davey: Mine looks a little different than the one you found. The blue tint of the lens looks a bit darker because it filters out quite a lot of non-blue light. It's surprisingly hard to find.

Jeff
 
Well i spent along time looking for that thing... i dont think ill have any luck finding it on its own. any chance of getting the name/type of microscope u got it from? if i have the specs i might be able to buy the lense straight from Olympus! im desperate... light... so white..
 
The microscope that I got this lens from is an Olympus CH-2 Compound Microscope. It's an older model and the Olympus website doesn't even list this microscope anymore. The filter is simply called a "blue filter". However, any microscope with an incandescent light source "should" have one of these blue filters.

Good luck
Jeff
 
There are standard photographic filters that do what that filter does. You lose a heck of a lot of light, like over 80%, if I remember right.
 
Paul, I don't know what type of filter you're using but mine definately does not block over 80% of the light. For a completely non-quantitative way of measuring the light, I've used a light dependant resistor (LDR) to measure the relative intensity of the light.

Surefire G2 w/P61: 200 ohms
With filter: 310 ohms

Where lower resistance is caused by more intense light.

So even though the relationship between light and resistance is not directly proportional, it can be seen that the reduction of light output is nowhere near 80%.

Sorry about the scientific writeup style of writing, I can't help it, been doing a lot of lab writeups recently. /ubbthreads/images/graemlins/smile.gif

Jeff
 
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