Near-Infrared Imaging

MidOpt_Near_Infrared_ImagingConventional charge-coupled device (CCD) and complimentary metal oxide semiconductor (CMOS) sensors can exhibit near-infrared (IR) sensitivity from 700 nm to approximately 1,100 nm and can be converted to an inexpensive infrared (IR) imager with the use of a near-IR bandpass filter.

Working in the near-IR can result in greatly improved contrast depending on the characteristics of the item under inspection. Information captured in near-IR images can be significantly different than those images captured with white light based on the absorption and reflection properties of the items being inspected. It’s usually impossible to tell how an image will appear in the near-IR without experimenting. Most digital cameras have excellent near-IR sensitivity, and these tests can be performed quickly and easily by placing a visible blocking/IR pass filter over the camera lens in conjunction with a broad spectrum light source or sunlight.

MidOpt IR bandpass filters are matched to the output wavelength of infrared light-emitting diode (LED) and laser diode (LD) illumination. In the presence of normal daylight conditions, the desired contrasting effect is often lost without the use of visible blocking near-IR pass filters.

› View Bandpass Filters
› View LED to Filter Guide
› Test with MidOpt Filter Kits

Applications Solutions

  • Pass IR & Block VIS Wavelengths to Increase Contrast
    Before: Barcodes on the bottle labels interfere with accurate reading of the shipping label barcode on the outer packaging. Infrared LED illumination alone does not create sufficient contrast.
    After: A BP850 near-IR Bandpass Filter on the camera separates the outer shipping label from the bottle labels. The bottle labels become invisible in the near infrared, resulting in absolute maximum contrast.
  • Pass IR & Block VIS Wavelengths to Increase Contrast
    Before: Without a filter, the edge where two different fabrics meet is difficult to detect.
    After: An 850nm near IR Bandpass Filter mounted on the lens, together with an 850nm LED spot light, provides significantly greater contrast. The fabric on the left reflects infrared light, while the fabric on the right absorbs infrared light, creating contrast.