#191134 DB395/870 Dual Bandpass Absorptive Visible + NIR

DB395/870 Dual Bandpass Filter passes UV-Violet and infrared wavelengths, effectively blocking all green and red light. These filters have traditionally found use in NDVI-type imaging applications. When using a single camera modified for aerial agricultural surveillance, incorporation of these so-called “Superblue” or “Infrablue” filters allows reflected near-infrared light (745-970nm) to be captured in the camera sensor’s red channel and reflected violet light (375-425nm) 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. While “Superblue” filters similar to DB395/870 have seen much use during recent years, for far better wavelength separation and contrast we strongly recommend the use of our newer DB475/850 or DB660/850 dualband filters instead.