Science
Read MoreThe Top spectrum is the full spectrum from a full spectrum Canon 40D, using a homemade transmission holographic grating. The bottom spectrum uses the same camera and grating, but includes the Astronomik Pro-planet 742 IR filter (hopefully aligned correctly). It may appear that the spectrum (with the filter) extends further in the IR, but it's just a difference in exposures of the two spectra. These are raw, unprocessed spectra.
Custom White Balance on 740nm IR filter
Notice the balanced histogram in RGB, when using a CWB
Daylight White Balance on 740nm IR
Notice the huge imbalance of the Red values on the Histogram, when not using a custom white balance for IR. Generally, these images are more difficult to process, especially if the color swap method is desired.
Camera LCD with Custom White Balance & 740nm
Notice how easy it is to visualize the scene, with a CWB
Camera LCD with a Daylight White Balance & 740nm
Trying to compose a scene is much more difficult when viewing the IR image like this: