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:: Monday, July 20, 2009 ::

Dark Flash

New Scientist report on an Invisible flash [that] takes photos without the glare
[via Null Device]

"Dilip Krishnan and Rob Fergus at New York University created the camera in an attempt to do away with intrusive regular flashes.

"To make their "dark flash" camera, they modified a flashbulb to emit light over a wider range of frequencies and filter out visible light. The pair also had to remove the filters that usually prevent a camera's silicon image sensor detecting IR and UV rays.

"Although the dark flash gives a crisp image without disturbing those in the picture, the results have an odd colour balance that looks like a view through a night-vision scope.

"To give the pictures more normal hues, Krishnan and Fergus used colour information from a brief, flash-free photograph of the same scene taken quickly after the dark flash image.

"The second image is dim and blurry, and so it lacks some of the fine detail of its dark flash twin. However, the researchers use software to combine the sharp detail from the first image with the natural colours from the second image, resulting in a remarkably natural end result.

"The results are similar to those achieved by using a long exposure without a flash, like this image. But a long exposure shot requires those in the image to remain still for a few seconds to avoid creating motion blurs. The dark flash technique uses short exposure times that prevent those problems."

This is a very useful looking tool. On the one hand it would be great for low light shots of easily disturbed subjects, such as pets or kids. On the other it would be a gift to the stalker / paparazzi contingent, eager to get shots of people with minimum intervention.

Imagine the day when this is standard on digital compacts / camera phones and anyone could be taking photos anywhere. A market would open up in ways to combat the intrusion. Perhaps with some form of personal alarm to the combined presence of IR & UV (as both are common enough individually) in the absence of natural light.

Some dyes used in clothing glow in UV so could the same technique be applied? Maybe with jewellery, a ring or bracelet or watch strap, that glows in IR & UV but is too dim to be seen in natural light. If you catch a glimpse of a flash from it when you're out in a club you know someone must have a stalker cam near by. Check your drink.

Labels: Photography, Technology

:: Dan 20.7.09 [Arc] [0 comments] ::
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