MidOpt Dual Bandpass Blue + 850nm NIR Filter DB475/850
The DB475/850 Dual Bandpass Filter has been primarily designed for NDVI imaging applications. When using a single camera, incorporation of this filter allows reflected near-infrared light (850nm) to be captured in the camera sensor’s red channel and reflected blue light (475nm) to be captured in the sensor’s blue channel (the green channel is not used). Even when using an inexpensive consumer camera (that has first had its IR blocking filter removed), this easy separation then makes it possible to post-process the red and blue channels for NDVI by performing the calculation: NDVI = (red – blue) / (red + blue). Healthy vegetation will absorb (not reflect) blue light and strongly reflect near-infrared light. Thus this information can then be used to apply a false color gradient to images to better highlight the contrast between regions of healthy vegetation vs. areas with stressed/diseased or no vegetation.