Introduction: - Infra Red radiation from the sun translates into heat when our bodies intercept it. However, on film and with digital imaging, infra red produces a variety of interesting effects. For this project, I used a Fujifilm S3 Pro IRUV digital SLR camera. Fuji developed a special sensor that is very sensitive to infra red radiation. Most digital camera manufacturers put an infra red-ultra violet blocking filter in front of the sensors, so people can shoot visible light images. Otherwise, the images would have a magenta cast that would "kill" other colors in the scene.
However, Fuji left off the filter in this particular model, so it would be useful for law enforcement officials and for fine art photographers. This camera can be used either without any supplemental filter to produce mild effects, or with a variety of other filters that block all wavelengths except in certain narrower bands of infra red radiation. To take visible light images with this camera, one has to use a special infra red-ultra violet blocking filter (also called a visible light pass filter).
This particular project features a graceful little white footbridge in a small public park, Sayen Gardens in Hamilton, New Jersey, USA. I've spent many hours wandering around here during various seasons. There are lots of photo ops here and many amateur photographers take advantage of them. No official has ever stopped any of us to ask if we had a photography permit. So I presume that only professional photographers shooting weddings and other special events on this property must apply for permits.
Visible Light Image: - First, for comparison, below is a visible light image of this bridge. I shot this with the same Fujifilm camera and the special B+W 486 UV IR blocking filter.
Click on images to see larger sizes.
Infra Red No-Filter Image: - Taking off the visible light pass filter produced this result. No post processing enhancement, just straight out of the camera.
Infra Red #92-Filter Image: - Using a Hoya #92 infra red filter produced the image below. This filter allows only wavelengths of pure infra red to pass, blocking all others, including near-infra red. No post processing enhancement, just straight out of the camera.
Using this filter presents problems, though. Since it is almost black, no visible light passes through it. The light meters on any camera will not work, as they are sensitive to visible light. Also, autofocus won't work, either, for the same reason, nor will manual focus, as no image is visible through the viewfinder.
So one must first take a light meter reading using the camera's meter and also focus. Then screw on the #92 filter, keeping the same focus. Then one must change the exposure to 4-8 stops over-exposed from the visible light reading. Thank goodness for digital quick time feedback. Now, of course, if one has a hand-held separate light meter, one doesn't need to remove the #92 filter for the light reading. But focusing will still be problematic at distances closer than infinity.
Post Processing: - Unless one wants a magenta-tinted image, one must do post processing on these infra red images. Using a variety of techniques with a variety of image manipulation software, such as Apple's iPhoto '06, Nikon's Capture NX, Apple's Aperture and/or Adobe's Photoshop various versions, one can get surrealistic wild or muted colors in addition to or instead of the magenta.
After experimenting with the first two listed software programs on these infra red color images, I've decided that it's easiest to work with images from the camera, no filter attached. The #92 produces so much magenta that it's really difficult to over-ride with these two programs. Perhaps in Aperture or Photoshop, one could have better results. So I have reserved the #92 filter for black and white infra red images. I now have installed Photoshop and could rework these images. But I like them as they are and so will leave them this way.