The Book
The ultimate resource:
A Field Guide To Time-Varying Light Sources
Photography
The photographs on this site and in the book are visually stunning. Photographing time-varying light sources is surprisingly easy.
On The Web
Guest blogger on Tristan Gooley's The Natural Navigator
Featured on Atmospheric Optics Picture Of The Day
Featured Artist on Light Painting Photography
Welcome!
I'm Dan Bennett and I'd like to welcome you to the Time-Varying Light Sources web-site. Observing and photographing time-varying light sources is a passion of mine, and the book is — as far as I know — the first and only book devoted to the subject. This web-site has some resources to get you started on this fascinating new way of seeing the modern world. And if you're a photographer, check out the photography section! Enjoy your time here, and I hope you catch the passion!
What's this website about?
This website is about lights. It's about neon lights, street lights, vehicle lights, moths, lightning and stars. It's about how to see these lights as you've never seen them before.
A lot of what we see, especially at night, is illusion. What the eye perceives as steady illumination is often anything but steady. A road that’s lit by street lights is actually dark for nearly half of the time. The red glow of a neon sign is the sum of thousands of pulses of light scurrying back and forth along the tubes. A document projected on an office screen is cycling through red and green and blue. All of these variations are too fast for the human eye to see... at least if you look in the usual way.
However, it’s not hard to train yourself to see – with your own eyes – the time-varying behaviors of many light sources. A few simple techniques with a mirror will reveal the secrets of many illumination technologies and naturally varying lights. And if you’re really good, you won’t need the mirror.
Of course, a camera can unlock these wonders too, and this web-site shows you how.
This is the companion website for the book, A Field Guide To Time-Varying Light Sources, by Daniel H. Bennett.
Most recent blog entries
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Exhibiting artist at a coffee shop
Written by Dan BennettI'm excited to be the exhibiting artist this month at the Land Of A Thousand Hills coffee shop in Roswell, GA!
These photos are all from my time-varying lights project, and were selected from my online gallery: http://photo.peeringbear.com/p188493375 (where you can order prints if you don't happen to be in Roswell, GA...
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Arcturus - twinkling star
Written by Dan BennettTwo nights ago I took a photo of the star Arcturus, using my Canon 70D camera with a 200mm zoom. The exposure time was 1.0 second, during which time I hand-held the camera and moved it during the shot. Here's the result.
The trace shows a massive number of variations (over 800!) of brightness and color. This is scintillation, better known as twinkling. Our eyes aren't able to see all these variations because (a) they're too dim, so we don't see the colors, and (b) they're too fast, so we see only the largest and slowest variations in brightness as twinkles.
The cause of these variations is atmospheric - the star itself is NOT twinkling! If you took a photo like this from the International Space Station, it would be a constantly bright, slightly orange line with no variations in color or brightness.