SureFire M2 Centurion and other questions...

Marion David Poff

Marion David Poff

Joined
Oct 8, 1998
Messages
5,403
Good Day,

Just found this Forum today, and I am hooked.

So, can the M2 Centurion be fitted with a red filter? I value my night-vision and love the low impact of red, so no red, no go. But I ask, because I really like the look of it. Any thoughts on it?

What are your other favorite red lights?

I have a red Photon II Microlight which is my constant companion, good for it's size.

Any help or information you can give is appreciated.

Thanks in advance,

------------------
Thank you,
Marion David Poff aka Eye, Cd'A ID, USA mdpoff@hotmail.com

My Talonite Resource Page, nearly exhaustive!!
My Fire Page, artificial flint and index of information.

"Many are blinded by name and reputation, few see the truth" Lao Tzu
 
Eye; the fallacy of red light preserving night vision dates from the '40's, at least. Unfortunately, it is not true.

Under scotopic conditions (hardly any light at all, or truly none), your retina undergoes what is called the Purkinge shift. This means that while under photopic (normal level light) and mesopic (low light) conditions, your retina is most sensitive to red (555nm), under scotopic conditions, it is actually most sensitive to green (510nm).

The thing most people don't realize is that for a light to preserve your night vision (which can take a few hours to fully recover), the level of the light must be so low that NO color is preceived. This means you are only using your rods, not cones.

For a good explanation of night vision preservation, go here:
http://www.corvus.com/kniffen.htm

It should be noted that at the light levels of Photon lights, no difference in preservation of night vision can be expected, or is experienced.

Hope this helps, Walt Welch MD

 
Eye; let's assume that you are talking about shining two lights, one white, one red, into your eyes under photopic or mesopic conditions. In other words, the Purkinge shift has not occured, and your retina is most sensitive to light of about 555 nm. (red light).

All things being equal, the red light should cause more 'spots.' The 'spots' also called 'dazzling' are due to the bleaching of rhodopsin (visual purple) in the retina, which renders the retina completely insensitive to light of any wavelength for some time, and relatively insensitive to light of any wavelength for several hours.

Since, in your experience, the white light caused dazzling, and the red did not, the logical conclusion is that the white light is brighter than the red light.

In my experience, it is very easy to accidentally cause dazzling with any color of Photon lights.

Remember, as discussed above, to preserve night vision, you must be working strictly with rods, and the objects illuminated as well as the light itself will NOT have any apprecable color. Your vision will be in black and white. If you can discern colors, the light is, however slightly, degrading your night vision. If you see spots, your night vision is screwed for several hours. You may recover partially in 10 to 15 min, but several hours to full recovery.

Hope this helps, Walt
 
For what it's worth, now that Walter blew your plan
smile.gif
, the Surefire line has accessory filters. There's a blue and a red. They fit the M2. I just tried my red filter on my M2, which currently has the p61 bulb in it -- that's bright red light!

Joee
 
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