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with MidOpt filters
MidOpt Filters: A Necessity, Not an Accessory
MidOpt filters are the premier solution for industrial imaging to ensure flawless control, dependable results, unmatched repeatability and exceptional image quality for monochrome and color vision systems. Filters have the ability to block all unwanted ambient light and pass only the necessary light output while increasing contrast and resolution.
Whether your vision system is counting items, reading codes or examining specific objects for defects, optical filters can help you achieve a more stable, accurate system. Many varieties of optical filters are available, depending on your application. Just some of the industries we serve include machine vision/factory automation, security and surveillance, license plate recognition/ITS, medical and life science, agricultural inspection/NDVI, aerial imaging, motion analysis, photography and cinematography.
History of Filters
For more than 100 years, photographers have used filters to reduce reflections, balance color and enhance the contrast in black-and-white photos. In hopes of achieving similar results, integrators across the world have attempted to use photographic filters in industrial vision systems. Some improvements can be seen with these filter types; however, they’re specifically designed for film cameras, and the spectral response (sensitivity) of film is from 400 to 700 nm, also known as the visible spectrum.
Digital cameras used in machine vision systems are unable to function at an advanced level with photographic filters because they have charge-coupled device (CCD) and complimentary metal oxide semiconductor (CMOS) sensors, which are sensitive to the ultraviolet, visible and near-infrared portion of the spectrum. In order to take control of lighting conditions and image quality, filters that perform well over the entire sensitivity range are required. We offer a variety of options and can help you determine which filter is best for your vision system.
Choosing an Optical Filter
In order to select the best filter, you’ll need to pinpoint your objective or the imaging problem you’re currently having. One of the most common filters used for enhancing vision systems is a bandpass filter. To discover the best bandpass filter for your application, use broad spectrum light source “white light” and a machine vision bandpass filter kit to highlight various wavelengths.
By viewing the resulting image each bandpass filter provides, you can determine the best color for maximizing contrast and reducing interfering light. In addition to bandpass filters, we offer many other filters to help reduce glare, remove saturation, balance color and more. Read detailed information about our filters below.
MidOpt Filter Types
Bandpass filters are often one of the easiest ways to drastically improve image quality. They are designed with a Gaussian transmission curve to emulate the output of the most common types of LEDs used in machine vision and are great for testing the effects of monochromatic imaging. All MidOpt bandpass filters have an anti-reflection coating to ensure maximum transmission.
Dual bandpass filters transmit two specific wavelength ranges through a single filter. They allow for natural color rendition during the day and near infrared illumination at night ensuring that precise, high-contrast images are obtained. This makes them a great choice for intelligent traffic solutions, security surveillance and agricultural inspection.
Longpass filters provide seamless transition from reflection to transmission and are available in many wavelengths, depending on the needs of your system. Longpass filters are best used in a controlled environment when multiple wavelengths need to be passed and are an economical solution for blocking excitation light in fluorescent applications.
Shortpass filters have unmatched transition from transmission to reflection and provide excellent contrast. They’re best used in color imaging to achieve natural color rendering and block infrared saturation.
Polarizing filters reduce reflection, enhance contrast and detect imperfections in transparent materials. They’re best used for applications that have overwhelming reflection when inspecting objects on shiny surfaces.
Neutral density filters reduce light saturation and are recognized in the industry as “sunglasses for your system.” Both absorptive and reflective style options are available, and they’re best used for applications where there’s overpowering brightness. They serve as great solutions for lens aperture control and increasing field depth.
Protective filters are best used for lens protection. They’re made from high-quality polished glass and optical-grade acrylic and are available with anti-reflection coating to maximize transmission. Acrylic protective filters have an abrasion-resistant coating and are useful for FDA/EMA applications.
Light balancing filters are used to achieve a more accurate color rendering and to keep costs low with LED or metal halide lighting. By blocking most of the blue spectrum transmitted by cool white LED lamps, the object being inspected has a more natural look to the human eye.
Optical filters are the simplest, most cost-effective way to enhance repeatability and to achieve the highest level of performance from your machine vision system. For more information, contact MidOpt by calling (847) 359-3550.