Night Vision Mini-Mag..

[LEDAdd1ct]

Hi all! This is my first thread, so please excuse me in advance.

I've had a little Mini-Mag sitting in the corner of my bedframe for maybe five years, getting no use since I discovered LEDs. I decided that after owning a host of bright lights, both 5mm, 1 watt Luxeon, 3 watt Luxeon, Cree, and a Malkoff on the way, it is time for me to get a night vision, red light. I also thought the poor mini Mag would be a nice host.

After researching here on CPF and the net, I decided my best course of action would be to install a Nite-Ize red LED drop-in into the light. I've read to death on night vision, including that a really bright light of any color will destroy your night vision. I've also read that taking sandpaper to the stock lense in a mini mag can diffuse the beam nicely. I did this to my lense with a piece of sandpaper, and the lense is definitely "clouded" over. I also purchased a mineral glass lense for the light. This leads me to my question.

The idea behind the light is to have something light, readily accessible, and cheap to run for those "midnight" (or post-midnight) errands, without disturbing others or killing my night vision. I am trying to decide which of the two options make the most sense:

Option One: Use the mineral glass lense with near "dead" batteries, i.e., batteries that are near dead in any other piece of electronics. This scenario would offer the following advantages: clear window for the light to get out, zero additional cost for batteries, low light because of near dead state of batteries.

Option Two: Use the diffused plastic lense I sandpapered down with more powerful AA batteries (fresh). This would offer more light, which would then be smoothed out by the diffused lense. However, more light would be lost (blocked), vs. using near "dead" batteries with the glass lense- less light to begin with, but more of that little light that exists to permeate.

What do you guys and gals think?

Many thanks,



LEDAdd1ct

 

[smvtsailor]

I've also read that taking sandpaper to the stock lense in a mini mag can diffuse the beam nicely. I did this to my lense with a piece of sandpaper, and the lense is definitely "clouded" over.

I could never get up the courage to do this. Glad it worked out!

I would go with option 2. That way the battery won't suddenly die when you need it, and you will get a longer runtime.

 

[Marduke]

Marry it with this:
http://www.niteize.com/productdetail.php?category_id=28&product_id=125

 

[Oddjob]

Go with a clear lens and batteries and improvise a red filter. Just find some thin red plastic cut to size and place over lens using bezel to hold in place. The benefit is it is free, you will preserve your night vision and your batteries won't suddenly die on you.

 

[Marduke]

Go with a clear lens and batteries and improvise a red filter. Just find some thin red plastic cut to size and place over lens using bezel to hold in place. The benefit is it is free, you will preserve your night vision and your batteries won't suddenly die on you.

A white LED doesn't put out much red wavelength light, and putting a red filter over one would yield almost no light at all.

 

[FASTCAR]

Red filter over white works fine. We did it in the military all the time.
Cameras also have red filters ( LEE) and they work just fine as well.

 

[Oddjob]

A white LED doesn't put out much red wavelength light, and putting a red filter over one would yield almost no light at all.

Maybe I just have decent night vision because I get enough light to see my way around the house at night :shrug:. To be fair though, it is my house and I know where everything is and with night adapted eyes I just need enough light so I don't accidentally step on my cat when going to the bathroom. I suppose it depends on what you do with the light. Disregard my suggestion if you need more light than just to find your way around.

 

[Marduke]

Red filter over white works fine. We did it in the military all the time.
Cameras also have red filters ( LEE) and they work just fine as well.

You're mixing up pure white light, and a white LED. White light has all wavelengths, and one color can easily be filtered out, which is why a camera can use a filter with natural or incandescent light. A regular LED is monochromatic for the most part, so trying to filter out one wavelength yields very little light for that wavelength. Incandescent bulbs are easily filtered with only a moderate loss in intensity because they produce white light, not monochromatic. The increasingly popular RGB LED's are a totally different story though.

 

[LEDAdd1ct]

I could never get up the courage to do this. Glad it worked out!

I would go with option 2. That way the battery won't suddenly die when you need it, and you will get a longer runtime.

Me too! I only did it because I already ordered the mineral glass lense (it was under two dollars).

Regarding the battery suddenly dying on me, I don't think that is an issue. As a true Flashaholic, I have a light for each purpose. For hiking, I can grab my Ultrafire C2 or Wolf Eyes Explorer, with backup 18650 cells in my pocket. For instant flood, my Malkoff with stippled reflector should work wonders. In this particular application, the dimmest red light possible is my goal. I have already purchased the Nite-Ize LED in red, so I have my light generator.

I was a little nervous at first about sanding the lense down, but I read about somebody else doing it here on CPF (or maybe on Google somewhere....?)

 

[LEDAdd1ct]

You're mixing up pure white light, and a white LED. White light has all wavelengths, and one color can easily be filtered out, which is why a camera can use a filter with natural or incandescent light. A regular LED is monochromatic for the most part, so trying to filter out one wavelength yields very little light for that wavelength. Incandescent bulbs are easily filtered with only a moderate loss in intensity because they produce white light, not monochromatic. The increasingly popular RGB LED's are a totally different story though.

Aye, I read about that long ago, and I decided that with LEDs, it was far more efficient to generate the red light I needed from the start. Now, the question is which is the best portal for those free-flying photons to travel through, and which type of power source to use.

 

[Marduke]

That sanded down lens should work pretty good. If not, try the mineral lens with the IQ switch on 50% or 25% mode.

 

[LEDAdd1ct]

I forgot to mention before- I also ordered a nice Kroll switch for it (by Judco). In the middle of the night, I don't want to have to mess around with twisting the head. Thank you for the I.Q. switch suggestion; I went with the Kroll for simplicity instead.

Also, I am going to be ordering some high-intensity GITD green paint, and painting the body of this light. I am thinking a nice polka-dot pattern to be frugal with the paint. Night adapted eyes will have no problem picking it up.

LEDAdd1ct

 

[Marduke]

I know you already order the Kroll, but the IQ switch blinks with a very small red led every couple seconds. Might be worth playing with if you find it in a store. Only $5.

 

[LEDAdd1ct]

I will consider the I.Q. switch. Of course, it is mandatory to experiment with *all* possibilities......

LEDAdd1ct

 

[FASTCAR]

Tested every light I own with a red filter. ALL are still bright.
LED, HID, and incan

 

[lumenal]

I've got the NiteIze IQ switch/ 3 red LEDs in a minimag, and it is THE light I grab for middle of the night nature calls.

Being able to click down the "redness" a level or two is useful. :candle:

And the blinking "find-me" red LED does what it is supposed to do, just a tiny red blip about every 3 seconds.

 

[Marduke]

Tested every light I own with a red filter. ALL are still bright.
LED, HID, and incan

As an example, let's look at a few spectrometer plots from LED Museum. A typical white LED will put out something that looks like this:

Notice that there is very little in the red wavelengths, and a very typical spike in the blue range. A red filter would essentially block all light except that in the red/orange region. This would yield somewhere around 1/8 or 1/10 of your total output, which is extremely inefficient.

Now, let's look at a typical incandescent source.

With a red filter using incandescent, your are getting around 1/2 to 2/5 of your total output making it through the filter and being displayed as red light. This is still inefficient, but not nearly as bad as filtering a white LED.

In summary, if you want a good red light, use an efficient red LED instead of having to use a white LED that's 10x as bright to get the same amount of lumens out the front.

Edit:
Just for giggles, let's look at an HID. It's somewhere inbetween, kinda sorta...

And the most efficient way to produce red light, from a red LED:

Edit 2:
For more giggles, how about compact fluorescent?

 

[LEDAdd1ct]

A picture...err...graph...is worth a thousand words.

Thank's for the graphs!

LEDAdd1ct

 

[Marduke]

A picture...err...graph...is worth a thousand words.

Thank's for the graphs!

LEDAdd1ct

Thank LED Museum, I just borrowed them from his website. He does great work.

http://ledmuseum.home.att.net/

 

[LEDAdd1ct]

He sure does-

his site was one of the ones that really pulled me into LEDs and their spectacular terrificness!

LEDAdd1ct