Lens filters for c-mount lenses (bandpass, longpass)
Lens filters, like a bandpass filter or longpass filter are placed on the front of a machine vision lens. The lens filter, blocks certain wavelengths of the light (color), making sure that only the required light wavelengths will be captured by the machine vision camera. The lens filter can also be used as a protective cover for the lens.
Different types of lens filters, bandpass and longpass filters
There are four types of lens filters:
- Bandpass filter (BP filter). Only a specific light wavelength (for example blue light, red light, green light) will pass the light filter.
- Longpass filter (LP filter). Only light starting from a specific light wavelength will pass the filter. As example, the LP420 passes all wavelength above 420nM (Blue + green + red + infrared) and block all wavelengths below 420nM (like UV light)
- Shortpass filter (SP filter). Only light till a specific light wavelength will pass the filter. As example, the SP420 blocks all wavelength above 420nM (Blue + green + red + infrared) and passes all wavelengths below 420nM (like UV light)
- Special filters. These filters allow specific parts of light wavelengths to pass and block. As example the UVIRCUT. This filters blocks all UV and IR light, but passes all visible light.
Mounting a lens filter, bandpass and longpass filters
Machine vision lenses have a filterthread that is used to screw the lensfilter on. Large lenses have a different filter thread then compact lenses. The most commen size for a lens filter are:
- M25.5xP0.5
- M27xP0.5
- M30.5xP0.5
- M35.5xP0.5
Not all our lens filters are visible online, therefore please contact us when you can’t find the right lens filter, bandpass filter or longpass filter for your application.
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