Provides uniform brightness at low light levels suitable for testing and calibrating electronic imaging devices used at low levels of luminance
Pro-Lite has released the Starlight uniform light source from Labsphere.
The USS-1200V-LL is an integrating sphere source which provides uniform brightness at low light levels suitable for testing and calibrating electronic imaging devices used at low levels of luminance, including night vision and target designation equipment.
The new Starlight source comprises a 12-inch integrating sphere with satellite sphere illuminator.
Uniform luminance is provided at sub-photopic levels, adjustable from 0.0001 to 100 candelas per square metre.
The axial luminance uniformity is better than +/-1% over the full 10cm exit port diameter.
Electronic imaging devices exhibit significant errors in their spatial response arising from pixel gain non-uniformity, lens vignetting and cosine falloff, image distortion, thermally generated electrons on the imager chip, and the spectral responsivity of the system.
For applications in optical metrology, the grey value of each pixel in the imager must also be scaled to quantifiable illumination values.
The exit port of an internally illuminated integrating sphere provides a near-perfect flat-field for calibrating and normalising the spatial response of imaging devices.
The correction technique involves capturing an image of the exit port of the USS-1200V-LL which creates a correction matrix in the camera control software to act as a gain control for each pixel.
The USS-1200V-LL joins Labsphere's established range of integrating sphere uniform light sources that provide luminance levels up to 400,000cd/m2 over source areas from 2.5 to 66cm.
