I just view my geckos using regular lights in the house, just keep it dimm in the room where I keep them. Night time out in the country isn't pitch black, especially on cloudless nights. Though the deep woods are very dark, less dense woods do let starlight and moonlight through. Then again my night vision is pretty good, especially out in the woods without the glare of street lights and cars headlights. When it's cloudy and rainy..is when I can't see squat.
Using an infrared light in the room but not actually in the cages, may be the best way to go, th is way, you don't have to worry about the temps getting to hot and you can see your geckos (unless you are like me and find red and blue light hard to view by. My brother used to light his room with a blue or red bulb...though it gave a rather cool effect for the entire room..it was hard to see details.
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PHLdyPayne