Dec 31, 2019
Incorporating commercial off-the-shelf lenses into your optical designs
In a presentation delivered at ENVISION, Keo Scientific Senior Optical Designer Dr. Craig Unick discussed incorporating commercial off-the-shelf (COTS) lenses into optical system designs. Keo Scientific designs and builds highly sensitive scientific instrumentation capable of wavelength-resolved imaging of sub-visual emissions from the upper atmosphere and ionosphere. Not only is Dr. Unick is a longtime user of OpticStudio, but he’s a proponent of COTS lenses for the right projects. Following is a look at the benefits of using COTS lenses, applications, and considerations.
Benefits of using COTS lenses
One of the major benefits of incorporating COTS lenses into optical designs is they can save manufacturers money. As Dr. Unick explained, COTS lenses are an inexpensive design shortcut to quick prototyping for high-quality, low- to mid-volume products. Photography lenses come with adjustable apertures and focus and possibly zoom, as well as a variety of focal lengths, some adjustable (zoom), with built in mounting flanges. COTS lenses offer a wide field-of-view, including fisheye, and large aperture with flat image surface. They also offer good longitudinal and transverse color.
Applications for COTS lenses
Keo Scientific is focused on space science and aeronomy, and COTS lenses can be incredibly beneficial for such projects. The company has incorporated them into telecentric lenses and cameras with narrow band filters and/or image diameter reduction. In addition, it used COTS lenses for the THEMIS All-Sky Imager, a joint project between NASA and Canadian Space Agency for ground-based imagers to photograph aurora. Keo Scientific designed and built the camera portion of this project, which uses a fisheye lens with some additional optics and filters for a 180-degree, horizon-to-horizon view.
Generally, COTS lenses are used for many government and military optical systems designs and in more and more commercial applications, as well.
Considerations: patents and embodiments
As Dr. Unick explained, there is no prohibition on using information in a patent and the patented technology in a design under the condition that the patent is not being reverse-engineered. Optical engineers can find patents on lens manufacturer websites and hobbyist sites—and places such as the Canon Camera Museum. Search by manufacturer, year, focal length, F-stop, zoom, and field-of-view—using terms like fisheye, wide angle, telephoto, reverse telephoto, and retrofocus. They can also search patent offices worldwide and do a search on Google Patents.
Embodiments are specific examples of the patented technology that demonstrate what is being patented and can help optical engineers immensely, detailing things like surface data, aspheric data, zoom lens unit data, etc. For examples of patents and embodiments and what to look for—as well a practical look at how to implement COTS lenses into optical designs in OpticStudio, refer to Dr. Unick’s full presentation here.