We upgraded to NextScan’s Lumintec lighting system yesterday. It uses LEDs (or more precisely, an array of strobed red LEDs) to illuminate the microfilm while it’s passing through the scanner rather than traditional halogen “hot lights.” Apparently, the CCD camera is more sensitive to the red wavelengths, and there are no IR emissions like you get from plain old “bulbs.”
Essentially, this was a quality-driven decision for us. The halogen bulbs tend to cause hotspotting in the middle of the image, an effect which is particularly noticeable on larger positive frames (such as the ubiquitous 35mm newspaper diazo readers found in nearly every public library nationwide, which represent a lot of the film that we process). Well . . . that issue is gone thanks to the Lumintec lighting.
It’s a night-and-day upgrade — lots more light (critical at higher reduction ratios, where the camera is physically more distant from the film) which lets us run stopped-down when appropriate, more even illumination, no heat, 1/10th the power consumption of hot lights (yes . . . we’re green!), sharper images and less blurring due to the strobing, no chance of lamp failure (changing the bulb was previously a rather labor-intensive operation and represented real down-time) , and, well, it just looks cool when it’s on. Our microfilm customers will see an immediate improvement to the quality of their images.
Obligatory NextScan white paper at: