The Public Laboratory for Open Technology and Science(PLOTS) present this surprisingly simple yet effective conversion of a cheap digital camera into a near-infrared camera. Now why would you want to convert your camera so it only takes pictures of something not visible to the human eye?
Taking photos with IR information can be used to generate NDVI (which stands Normalized Difference Vegetation Index) and for NRG images. NDVI and NRG are methods taking the information in pictures and quantifying the amounts of infrared and other wavelengths of light reflected from vegetation. This can be used to evaluate health of vegetation by comparing ratios of blue and red light absorbed versus green and IR light reflected. It’s a snapshot of how much photosynthesis is happening. This is helpful in assessing vegetative health or stress. (Read more here:https://www.agronomy.org/publications/jeq/articles/36/3/832)
If you’re interested in learning more about Near-IR or Grassroots Mapping, PLOTS website is a wonderful resource..