Future Cameras May Be Equipped with Invisible Flashes

Future generations of photographers may one day look back and wonder why we often blinded each other with painfully bright flashes of light for the sake of proper exposure.

NYU researchers Dilip Krishnan and Rob Fergus are working on a dark flash that eliminates the “dazzle” effect of regular flashes in a low-light room. They’ve created this camera rig that combines common infrared photography techniques with an ultraviolet flash that produces a dim purple glow instead.

The team placed an infrared filter on the lens of the Fujifilm S5 Pro, which is has a modified CCD sensor that specializes in IR and UV photography. To supplement existing UV light, the team created a modified filter on an external flash to emit only UV and IR wavelengths.

Still, the project has a few hitches. The image produced strips all normal colors out, and all subjects turn a sickly green color. The image requires heavy color correction. In order to reintroduce correct wavelengths of color, the photo has to be combined with a regular photo of the image captured in ambient light — merged similarly to HDR photography. Obviously this is a huge obstacle since photos of objects and people in motion is impossible.

The above photos are the photos take with the UV flash (F), with ambient light (A), the composite image (L) that combines the UV and ambient, and finally, a long-exposure image of the same scene for comparison (L). It’s pretty close, though some texture detail is lost, but it looks less grainy.

The techniques used are nothing new — photographers have been using IR flash to shoot in situations that require subtlety for years — but combining IR with UV is a pretty nifty idea. It will be some time before applications like this are practical — but perhaps they could become more useful if they used stereoscopic lenses common to 3D cameras to take two photos at once.

  • Mike

    Why is there a catchlight in each pic?

  • Anonymous

    My guess is that there is a distant or slight directional light to the left and behind the photographer. The photos were not shot in pitch-black darkness, but a really dim low-light situation — probably illuminated by that single directional light that casts the shadow and causes that catchlight in his eye.

  • David Ritchie

    There’s no details on the (R) image. Which one should be L and which should be R ?

  • Anonymous

    Umm, if there is a flash illuminating the subject, and the camera is sensitive to that flash, then a catchlight is pretty much inevitable.

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  • Ricardo

    Great idea, now everyone will get free tans when photographed :)

  • Anonymous

    The process seems to hide the mole on his right cheek. Seems interesting, though with some compromises. I almost never use flash, though I probably should try a good one some time. I try to get the biggest aperture I can manage f/2 and below, and nudge the ISO up on a camera with a good sensor. I’ve gotten good results at night time outdoors with just string lights on a 5D mkII and a 50mm f/1.4 lens.

  • Anonymous

    Something else to think about, lenses these days aren’t good at passing infrared and ultraviolet. Camera and lens manufacturers have been getting aggressive about blocking them as they pollute the colors in the picture, and lenses these days have more elements and more optical materials and more coatings. I wonder if this solution is fully baked with that in mind.

  • Shaunlamont

    why publish articles like this when its complete crap…this is just filler bullshit

    you are not going to take a monochromatic, narrow wavelength illumination source and get successful lighting….theres no “rainbow” separation from this

    f’in idiots…..

  • Outdoor String Lights

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