How important are filters for image processing and machine vision?
Georgy Das: Filters are essential for image processing and machine vision in several ways. A bandpass filter, for example, can significantly increase contrast and control the effects of unwanted ambient light, leading to more efficient image processing and ensuring repeatability. Shortpass filters, on the other hand, help create natural color renditions when used with color cameras that don’t have a near-IR cut filter supplied. Protective filters not only provide the precision optical quality required for specific applications but also offer protection from debris, liquids, and other potentially damaging contaminants in challenging environments, depending on the substrate and coatings selected. These examples represent just a small sample of the filter types available, but they illustrate the substantial positive impact that filters can have on machine vision applications.
What do I have to pay particular attention to when choosing the right filter for my application?
When choosing the correct filter for an application, it typically comes down to determining which wavelengths need to be passed and which should be blocked, or if another effect is desired, such as reducing specular glare with a polarizer or decreasing transmission with a neutral density filter. It’s also crucial to consider key features like the design of the passband, how the filter performs at higher angles of incidence, and whether the applied coatings are optimized for the useful wavelengths. Ensuring that the filters are inspected for both flawless optical quality and performance is equally important. There are also times when you may need help figuring out where to start. For those situations, I recommend our versatile line of Filter Kits. These kits, such as our brand-new FK201, feature multiple filters with flexible solutions for affixing to lenses with various thread sizes. The Filter Kits also help you test the effects of monochromatic illumination and select the ideal filter for your application.
You are currently concentrating on filters. Wouldn’t you like to include lenses in the program?
While it’s not entirely out of the question, we believe our true expertise lies in designing and manufacturing the highest quality filters, protective windows, and custom optics solutions for machine vision and beyond. We have always assisted our customers in designing custom lenses and partnered with lens manufacturers to offer a complete solution. For special projects, we also offer smaller board lenses commonly used in embedded systems, along with the filters that can be mounted or optically cemented for a robust, streamlined solution.