Last spring, Barry Warzak of Midwest Optical Systems (MIDOPT) in Illinois contacted Ned Horning about writing an article on dual bandpass filters. Ned got me involved, and Barry also became interested in having us try some of the new filters he was developing. The primary focus of MIDOPT is industrial machine vision filters and lenses, but Barry recognizes the potential in the emerging market for agricultural analysis and aerial imaging. Barry has sent us samples of 15 different filters that could be used for infrared plant health analysis. Some of these are fancy dichroic filters that transmit one or two very narrow bands of color, and others are high quality glass filters that have spectral qualities similar to Wratten 25A, Wratten 15, or Schott BG3 filters.
