Except for the fact that their web site is more confusing than the plot of Lost, MaxMax is a really interesting company. The trick to the one camera NDVI is special filter that they apparently have custom-made (I think by Schott). The filter replaces the IR block filter in the camera. It passes IR and blocks all visible red. So the red channel captures only IR light and the blue channel captures normally. To calculate NDVI, they use the blue channel (light that plants use for photosynthesis) for visible light, and the red channel for IR (light that plants reflect). It is perfectly legitimate. As far as I can tell, Schott does not sell this filter as part of their extensive line of filters. So you have to pay MaxMax $725 for a converted Powershot. If all you wanted was aerial NDVI, this is a smart way to get it because you have to fly only one camera (no shutter sync), and there is no registration of images to do afterwards. But you do not get a normal RGB image.