This filter is not an astronomical filter in the classical sense! Rather, he is converted DSLR CCD and CMOS cameras, in which the built-in IR filter has been removed or replaced by an altered IR filter, put into the position to be fully usable again for terrestrial photography.
The OWB ( Original White Balance ) filter shifts the entire spectral range of the converted DSLR camera so that it can be used without restriction again for terrestrial photography. The decision, if necessary, to use a camera exclusively for astrophotography thus eliminates and relieves considerably the wallet!
Mode of action: The OWB filter is so elaborately calculated and constructed that the images of the converted DSLR camera again deliver results that correspond to the daytime vision of the human eye. This allows the camera to work with its known sizes for the various preset white balance values and of course with the automatic white balance (AWB). This was previously not possible with converted DSLR cameras without filters.