larryepage wrote:
There was recently a discussion here from a member who had found a D90, 18-70mm Nikkor lens, and some other great stuff at a thrift store. When he tried the D90, the results that he got were surprising, and a discussion ensued around what was "wrong" with the camera and whether it could be fixed. Originally, several of us thought that the problem might lie in the white balance adjustment system, but additional information eventually led us down the trail of the camera being an IR conversion of some kind.
Fast forward to today, which finds the camera in my locker, with the assurance that it is a conversion to an infrared-sensitive camera. While some work remains to determine exactly what the cutoff wavelength is, I now know that the conversion is to infrared-sensitivity only, with no remaining sensitivity to visible light wavelengths (verified by testing with an assortment of colored LEDs, known to have no IR in their output). In addition, it has been verified that the conversion process included removal of the RGB Bayer filter array, so the camera is now monochrome only. The only color component that imparts to images is that which arises from the white balance biasing system, which is still functional in the camera. Camera output is fully monochrome.
I have been working with the camera, learning its characteristics, as well as how to achieve proper exposure and focus. I'm not perfect yet, but I've learned quite a bit, and have gotten some images that at least have some level of interest, even though they really are still mostly technical exercises. Thought some of you might be interested in seeing how it's going, especially the member who is convinced that I've been tricked into buying a broken camera.
Here is a recent image captured after a local snowstorm. If you look carefully, you can see some residual snow on the ground.
There was recently a discussion here from a member... (
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This looks like a sensor filter conversion to c. 830nm. I have that conversion because I am more interested in good B&W images than the very colorful possibilities of the full spectrum conversions. This 830nm conversion usually needs a tripod and slower shutter speeds. I use Live View to guide me in all of my camera settings and manual focus. Your histogram is still based on visible light and will not be a good guide for IR.