Two New York University researchers have created a camera that takes photos with an "invisible flash" of infrared and ultraviolet light to a smarter way to take photos in the dark.
To make a camera with the advancement, which they call "dark flash," the duo modified a flashbulb to emit light over a wider range of frequencies and filter out visible light. They then removed filters that usually prevent a camera's silicon image sensor from detecting IR and UV rays.
There are pros and cons to the approach: though a "dark flash" creates a crisp image, results have an odd color balance (think night-vision).
To remedy the situation, Fergus and Krishnan combined the result with color information from a flash-free (thus dim and blurry) photograph of the same scene taken immediately after the dark flash image. The pair combined the two images using software for the final result.
Unfortunately, some hurdles remain: some objects (such as freckles) absorb UV and IR light, and don't appear in either the "dark flash" version or the final composite image.
Fergus and Krishnan will present their work at the Siggraph conference in New Orleans in August. [via]