Sunday 1 August 2004

Making of an IMAX Film

John Stoke describes the making of the Hubble Space Telescope award-winning short feature entitled Hubble: Galaxies Across Space and Time, available for showing in IMAX theaters worldwide.  This was my summer job in 2003.

Such large-format film venues are common in the communities we serve, but we’d hitherto not seriously considered working in the large-format film medium because conventional production in this format costs hundreds of thousands of dollars per minute, far more than our modest budget could support.

So we came up with an unconventional idea: A series of trailer-length (under three-minute) explorations of the universe as seen by Hubble, to be created digitally almost entirely in-house at modest cost and offered to the institutional large-format film theater community at very low cost as a public service.

Would the community support the concept of adding a “Hubble Bonus” to an existing feature movie? Could we find a way to create the series “pilot” with almost no money at all?

A chat with Jim O’Leary of the Maryland Science Center led us to David Keighley of DKP 70MM Productions, Inc., a subsidiary of IMAX Corporation. David received our concept with warm enthusiasm and immediately offered to sponsor the project by donating the services and materials to create a negative and first print from our digital frames – a generous contribution without which the project would not have been possible.

With DKP’s support in hand, it next became a matter of selecting a subject. Hubble excels in virtually all areas of visible-light astronomy, but one recent observation program quickly became an obvious subject matter choice: The Great Observatories Origins Deep Survey (GOODS), a collaboration between Hubble and a large number of other ground- and space-based observatories. Among Hubble’s contributions to the GOODS project is an enormous, deep image of a field of galaxies that reveals, in an area of the sky comparable to that covered by a quarter moon, almost 30,000 galaxies, some of them so far away that their light has traveled some ten billion years to reach us. The image is, effectively, a gigantic “core sample” of the universe that reveals what galaxies looked like in epochs past.

Through a technique that astronomers call photometric redshift it is possible to estimate with good accuracy the distance to many of the individual galaxies in Hubble’s GOODS image. The photometric redshifts were obtained by a separate, ground-based campaign of observations by the GOODS team. Since the GOODS team made a parallel effort to get photometric redshifts, the Hubble data was immediately useful for 3D visualization.

Thus was born the idea for the central feature of our pilot film: To make a 3D flight through the field of galaxies, taking the audience on a trip into the distant past.

Conceptually, what we had to do was quite simple:

  • Transform the GOODS scientific data into an image suitable for visualization.
  • Isolate and extract the individual galaxy images.
  • Place individual galaxy images in correct 3D distances as sprites in a 3D animation program.
  • Fly a virtual camera through the field, recording a series of digital image frames at 5.5K x 4K pixel resolution.

Accomplishing these tasks on a 627-million-pixel image stored in a unique scientific data format required several months of dedicated effort by a team of Hubble image and visualization experts.

Frank Summers led the development of the 3D flythrough, working with both the GOODS team and summer student intern Leigh Fletcher. Greg Bacon, supported by John Godfrey and Bryan Preston, built the 2D animations that lead to the 3D sequence. Image expert Zolt Levay transformed the scientific data to the visualization image, and his colleague Lisa Frattare cleaned both the overall image and the largest individual galaxy images.

An important tool in the development effort was a “Visualization Wall” in Summers’ lab, a 4x4 array of LCD monitor panels, each driven by its own dual-CPU Linux PC. The array of monitor panels is like an IMAX screen in miniature. The computers, running in synchronization, can feed 24 frames per second to each of the monitors. A viewer, seated about a foot from the LCD panels, enjoys a visual experience that mimics the field-of-view, motion, and image resolution of a large-format screen (if not its sheer scale, contrast ratio, and seamlessness).

After months of late-night test renderings, a final rendition of the entire flight sequence was accomplished and married to the opening image pans and titles created by Bacon, Godfrey, and Preston. A narration by actress Barbara Feldon and a surround-sound score by space music composer Jonn Serrie were mixed at ToyBox Toronto with the invaluable help of studio engineer Cory Mandel.

The result is a mesmerizing flight into the early universe that puts genuine astronomical research data in front of the public in a truly approachable and enjoyable way.

On Tuesday, March 9, 2004, we premiered the film at the Maryland Science Center as the grand finale to a science writer’s workshop on the Hubble Ultra Deep Field – the deepest image of the universe ever taken. That print then showed in Baltimore during the summer of 2004 with additional early openings planned in San Diego, Detroit, and at the Kennedy Space Center Visitor Complex.

This is just one of many Hubble shorts that we could imagine creating; the telescope could scan the heavens for thousands of years before covering it all! Since the first showing of the pilot we’ve received inquiries from over 25 large-format theaters interested in enriching their visitor experience with this “added bonus,” and the film has won its first award, Best Short at the 2004 Large Format Cinema Association Film Festival. If all this interest translates into a positive audience response, we’ll be looking for the means to initiate a series of such short films covering the rich gamut of Hubble’s vision.