NavList:

Active IR means that the device is using an IR flashlight like gl metioned earlier.  Passive means its just using ambient available light.  Active IR is limited to the distance your IR flashlight can project light.  Just like a normal flashlight but its not visable to the naked eye.  All night vision devices are simply a light amplification tube in one form or another.  Newer generation's have more amplification.  If its a dark night with not alot of ambient light they dont help you much. If its a bright night (such as half or full moon) they can look like daylight.  On a bright night these might let you see a horizon after twighlight.  Stars will look brighter.  You would most likly have to go to a "darken ship" mode as any white light will overwhelm the tube and wash everything else out.  When I'm doing army stuff (dismounted light infantry patrol) I make sure at least one guy on my fireteam uses night vision.  It's more trouble than its worth alot of times because you still cant see much and makes your eyes night blind watching the bright green screen but if you don't use them you give the enemy free reign to "go active" and blast ther IR lights everywhere they go. We also use the IR lights to "flash" and signal friendly forces.  If you are taking star sights I don't think the IR light will help you at all.  I would just use it in passive mode. 

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