

Dark Flash Photography - UV/IR Flash Instead of Visible Light - anarcticpuffin
http://cs.nyu.edu/~dilip/wordpress/?page_id=38

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jberryman
The photographer Weegee used to bring his camera with infrared film and an
infrared flash bulb into darkened movie theaters and photograph the audience
behind him. Back in the 40s!

[http://museum.icp.org/museum/collections/special/weegee/weeg...](http://museum.icp.org/museum/collections/special/weegee/weegee14.html)

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pbhj
Your link is broken for me, shorten to the first /weegee/ and click
"entertainment", then browse.

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socratees
That reminds me of the video where Richard Feynman talks about light.
<http://www.youtube.com/watch?v=6b6DpT2YLI4>.

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jrockway
Seems like a good idea. I guess the invisible light provides high-resolution
luminance data, and the low-resolution visible shot provides the chroma. Since
our eyes are more sensitive to luma than chroma, the image is not degraded
much compared to a "correct" exposure.

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derefr
And, since the chroma _is_ degraded, it automatically gives the images that
magazine-cover "beauty blur" effect.

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elai
Soft focus is spherical lens abberation, something you would usually want to
avoid.

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derefr
Correct, people normally avoid soft focus _in the luminance curve_. Running
the chroma curve(s) through a low-pass filter, however, is the "Make My Logo
Bigger Cream"[1] of the commercial photography world.

[1] <http://makemylogobiggercream.com/>

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electromagnetic
This process merges a UV/IR photograph with an ambient light visible
photograph. However, if you want to take a photograph of someone in the dark
they're going to end up looking like the bogeyman.

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chancho
It's not supposed to be night vision. All I want out of a digital camera is
the ability to take hi-res indoor photographs without flash. Consumer-level
cameras have modestly-sized CCDs that can't gather enough light fast enough
indoors, so the picture is either noisy (not enough light gathered) or blurry
(exposure is too long). This aims to remedy the former by using the UV/IR
photo to smooth out the noise.

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skalpelis
A fast lens might help (if you're into SLRs). f1.8 50mm prime is cheap, though
anything faster will cost you.

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jacquesm
What he means with 'fast lens' is a lens with a large aperture so that more
light reaches the film/sensor in a shorter time.

There is nothing inherently 'faster' about the lens, it is just a figure of
speech.

