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Grow at the Edge

Here are some images from my first week shooting IR ‘infrared’ Photographs (tech / how-to information below).  Portland has been cloudy mostly, so just shooting artificial light, around the block, and in the trees; not shooting much in full sun. I still haven’t settled on a processing method either.  Tell me what you think and leave your thoughts and start some discussion below!

And some with more color in.

So how did this happen?  I took an old Pentax K100d, opened it up and removed the IR Cut-Off filter.  This wasn’t too hard, I had assistance from the internet, and I found a service manual that laid out the steps (I can share with you).  I did cut one of the flex cables to the display, so if anyone has or knows where to get a replacement for that let me know.  But after a few hours I the cut-off filter sitting by my camera in the form of a nice shiny blue piece of glass.

What cut off filter? well, you see, digital CCDs and CMOS sensors it turns out are sensitive to more than just what the eye can see, they also are sensitive down into the Infrared.  To balance things out most camera’s have a blue cut-cut off filter which passes visible light but blocks infrared.  (this actually causes problems for some Astro-photographers as many celestial bodies emit a lot of radiation down past red into the infrared, so if you see a camera marketed for astrophotography, it probably has a cut off filter that still allows some of the deep red wavelengths).

With the filter removed the camera now ‘sees’ infrared light.  This means there is a lot more light bouncing around (from the sun) and hitting the camera leading to lots of over exposed images.  Various things reflect infrared in ways that might seem surprising (IR is after all something we do not see, and therefore we have little to no experience with).  Leaves are the classic example, appearing very bright rather than green or gray.

Different effects can be achieved by using different levels of filtration (I use a cookin SFX filter) to block the visual spectrum and pass only portions of the red and Infrared light through to the sensor.  Also by applying different processing techniques (the image you get straight from the camera is red biased… The camera sensor and software is engineered to see the visual spectrum, and now is getting a bunch of extra red / infrared information.  Maybe I’ll talk about this more in a future post, but feel free to send me questions!

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