I want to do paranormal investigations and I have seen a “full-spectrum” camcorder for $300 on eBay. Is that equivalent to the UVCorder?
A. We have not tested one of these products. The listings usually show a spectral curve that suggests that a piece of UV filter glass (probably Schott UG-1) has been placed over the lens. This filter cuts out visible light, but passes near-UV and near-infrared light. The problem with any kind of investigation with this camera is that the user does not know if what he or she is seeing is a UV signal or a NIR signal. Both will look similar to the camera. It is very hard to believe that these devices have much response in the UV band. Ask the seller what the UV response of the system is, not just the filter, but the filter, optics and sensor. Q. I know you can use black and white film and a filter to take reflected UV images with film cameras. How is this done? A. Standard black and white film (Kodak T-Max 400, for example) is sensitive to UV light. One can load it in a standard 35mm SLR camera and place a Wratten 18A filter or equivalent on the front of the lens to block visible light an
