10
November
2011
|
03:36 AM
America/Los_Angeles

How To Take A Massive Photo Of The Milky Way

Armed with a laptop and six digital cameras, Nick Risinger, an amateur astronomer created a 5,000-megapixel panorama of the universe from tens of thousands of digital images.

By Intel Free Press

On his way to snapping 37,440 digital photos, Nick Risinger never once asked anyone to look at his camera and smile.

Risinger's subjects were the millions upon millions of stars and solar systems and galaxies filling the night sky. The single astounding panoramic image he has created -- stitched together into a seamless 5,000-megapixel shot -- is riveting astronomers and sky watchers worldwide.

And it's online. With the click of a mouse, you can zoom through the eons to peer into pale yellow gas clouds, past purple nebulae, across vast belts of stars and then into the dim light of the distant universe fading gradually to infinity.

The image contains a staggering 20 million stars, Risinger said, "Floating on a stage of unimaginable proportions."

The largest-ever survey of the heavens rendered in true color, Risinger's image is a feat of equal parts of astrophotography and computing.

"I'd often set it up and just let it run overnight," said Risinger, describing how he would batch-feed his laptop with hundreds of new sky images at a time.

He estimates that his quad-core Intel-based system chalked up "several weeks of actual processor time" over the yearlong project. Would even more processing oomph have helped? "Not really," Risinger said. The limiting factors were human -- taking the photos, and writing the software scripts that performed the electronic image stitching.

A bank of six digital cameras captured the shots. Risinger bolted them together and had them tracking on a clock drive to the rotation of the Earth.

After quitting his job as director of marketing for a countertop company in Seattle, Risinger, 28, began a journey with his retired father that saw them log some 60,000 miles over the course of almost a year.

"Astronomy has always been a personal fascination of mine ... it was just a matter of finally going out and doing it," he said.

Risinger hunted for night skies free of light pollution across remote stretches of the American West, in such places as the high desert ghost town of Brothers, Ore. In South Africa, with springboks and zebras eyeing him from a distance in the dark, he aimed his cameras skyward to capture the glittering night of the Southern Hemisphere.

He was dazzled. On one dark ultra-clear evening -- far below the equator and nowhere near any city -- our ownMilky Way Galaxy was so bright and high above the horizon that it actually cast a shadow on Risinger as he set to work.

Risinger said he is unsure what project he'll next pursue. It's hard to imagine, though, what could possibly surpass the one he just finished.

"The click-clack of the shutters opening and closing became a staccato soundtrack for the many nights spent under the stars," he related at his website. "Occasionally, the routine would be pierced by a bright meteor or the cry of a jackal, each compelling a feeling of eerie beauty that seemed to hang in the air. It was an experience that will stay with me a lifetime."

The tools Risinger used for the Sky Survey:

Hardware:

  • Cameras -- Finger Lakes ML-8300 monochrome
  • Lenses -- Zeiss Sonnar 85mm f2.8
  • Filters -- Astronomik LRGB, Astrodon Ha
  • Mount -- Takahashi EM-11 Temma 2 w/ custom armature
  • Generator -- Yamaha EF1000iS for U.S. trips
  • Laptop -- Intel Core i7-820QM running Linux Fedora, 8GB RAM w/ 4TB external storage
  • Software:

  • MaximDL -- mount control, image capture, and creation of calibration frames (dark, bias, flat)
  • IRAF -- many scripted tasks such as up-scaling, registration, saturated pixel replacements with scaled exposures, stacking, and median background modeling
  • SExtractor -- building each frames list of objects
  • SCAMP -- cross referencing to create position and distortion headers
  • Swarp -- reprojection and stitching of frames
  • PixInsight -- generate final LRGBHa color composite, midtones transfer function, noise reduction
  • GIMP -- final assembly, curve and saturation tweaks