Introduction to Infrared Photography
A digital camera by its nature is sensitive to infrared light. Therefore, digital cameras have infrared blocking filters. We can modify a digital sensor to be sensitive to infrared light by removing this filter and replacing with a filter that blocks visible light. The camera will function as it normally does but sometimes the metering may be off a little so bracketing may be helpful.
The attraction of Infrared photographs is that they exhibit false-color or in a black and white photograph very dramatic almost dreamlike images. One of the main effects is that foliage will turn white because of it's chlorophyll fluorescence. In addition skies generally turn very dark blue(or black in the case of B&W conversion) compared to visible light. Clouds and reflected clouds in water tend to be very striking. The wavelengths of infrared light also make skin look milky and eyes look black. These effects are not truly achieved unless you are using a DSLR camera that has been modified. “Infrared” filters that show up in editing software do not produce the same effects.
Custom white balance for IR should be done in the same way that a custom WB is set but instead of filling the frame with white use green(like grass) as a target neutral.
There are several choices in the filter choice when you convert your camera to IR. Depending on the effect you are looking for will decide which filter is best for you. In addition you will need to choose what lens you want to use with your newly converted camera. The lens is calibrated to the camera when it is converted. Some lenses have hotspots are are not useable.
The infrared image captured in camera must be edited with some editing program like Lightroom or Photoshop.
Make a Levels Adjustment layer
Select red as output, drag red to 0%
Then drag blue to 100%
Next select blue channel, set blue channel to 0%
Then drag red channel to 100%