Monday, February 05, 2007

New Near-Infrared Filter

I found a NIR filter on ebay from some obscure chinese company for $40. It says it works around 900nm (red is 650nm). I thought I would see if my camera is sensitive to these wavelengths. It turns out that my camera records light in its red, green, and blue pixels. I don't really understand that one, but it's mostly red with some blue. At any rate, the haze was cut down fairly well after stacking 30 exposures, but it was nowhere near as good as the one before using no special filter. I can't tell if I needed to stack more images, or if it's a light-leak issue. The Big Island at sunset had some really cool texture either way.


Blogger Liz said...

Wow! the texture is crazy! What is that? It's not seeing through the vegetation, right? How does this new pair of sunglasses work?

7:07 AM  
Blogger geekedout said...

it doesn't have much to do with vegetation, just that it's sunset and you can see through the haze of the atmosphere better. it works because the sky is "blue" the sky has a lot of blue light, not so much red light, and even less far-red (near infra red). the longer the wavelength the more clear the sky (until lots of other stuff happens).

9:33 AM  
Blogger Liz said...

What does that have to do with the texture on the mountain?

3:15 PM  
Blogger geekedout said...

the texture is just the shadows on the topography. nothing to do with vegetation. you just see the normal shadows that would otherwise be lost in the haze. you would see these shadows from the far IR to the far UV.

6:25 PM  

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