Friday, August 16, 2013

Bears and more Bears

I've been experimenting with a new IR camera I recently built. Since the camera is viewing the full spectrum of light, the colors are slightly off as there is no longer an IR filter on the glass inside the camera. Thus far I haven't noticed any difference in wildlife behavior compared to the white flash units I normally use. These are a few pictures from one spot in northern N.H. It was close to a bog and the black bear traffic was incredible to watch. At least 6 different bears visited this location in a 19 day period. Some spent time feeding in the blueberry patch directly in front of the camera or trying get pry the camera off the tree.


  1. Nice hack Peter. I generally just convert the pics to B&W because it's easier on the eyes. What camera did you use for this hack? Even with the IR filter over the flash, you're still getting good output and scene fill.

    1. This was an IR P41 but instead of the no glass hack I placed a piece of "normal" glass that I had been saving from Whitetail supply back when they were still in business. I was pleased with the focus and it's definitely a notch down from the white flash, but I still see a bright red flash day or night and I was hoping the IR would be less visible. Thanks for the good advice on changing it to B&W, it didn't register with me to do that. The next IR pics I post will definitely changed. Thanks!

    2. Nice. Sounds similar to the pentax e50 IR hacks I did. But I think the pic quality is a little better.

      On the IR "red flash" you're seeing - you can stop that if you want. While we call these flashes "IR", they really aren't because they don't truly push the flash into the infrared end of the spectrum, nor allow the CCD to show body heat and like. They're more "near red," giving off a wavelength of red light right on the edge of the human/animal vision. Sooo... get yourself a piece of red glass that pushes even more into the infrared, and you'll see less "red flash." I don't remember the numbers of the top of my head, but I think the typical red filter we get with the kits to put over the flash is around 600nm, and if you get one that's 800nm or more, the red flash almost goes away.

    3. I didn't know that, I'm glad you mentioned it! I would assume that as I move up to 800nm or even higher, there would be less light output from the flash and the pictures might appear either grainy or blurred at night due to lack of light? It would be nice to find a good balance between an "invisible" flash and bright/clear night pictures. If I grab a higher nm filter I'll post some comparison pictures. Thanks again for all the info.

    4. Yes, the intensity might drop. Depending on the camera and its flash. Each flash has an output profile/curve that peaks in our visible wavelengths, and drops off at the IR and UV ends. When you put the filter over it, you're blocking off all the flash light but that one wavelength. For some flashes, the output at 600nm and 800nm might be pretty much the same. For others, it could drop off fast from 600 to 800. As you mention, the camera will attempt to compensate by bumping up the ISO, and thus making the photos more grainy. That's a problem I've had with the Pentax hack - its flash output is weak to start with, and with the IR filter it drops down so much that the cams aren't much good beyond about 10 feet. The Sony s600s, with their huge flash output, have proven to give the best IR pics, but they're really hard to IR hack properly.

    5. Some really good information here, it makes me want to experiment more with IR. Thanks for all the info! I'll be putting it to good use.