Infrared blue


Two odd things about infrared cameras:

1) Even thought blue is well outside of the IR range, some things that are blue to the human eye get picked up as blue by the converted camera. I did some testing and I’m pretty sure that this is how this particular camera sees deep infrared. I have no idea why visible blue also reflects as deep IR, but it does.

2) Some lenses have hotspots, where the infrared light hits the sensor and bounces off to hit the rear of one of the elements of the lens (somewhere in front of the aperture) and bounces back to get detected again. In the final image, this shows up as a ghostly light, usually in the center of the frame. This effect usually just shows strongly up at certain aperture settings.

In this case, both effects worked to my advantage.