One Dome, Two Skies

Path to the main entrance of DeAnza College's Fujitsu Planetarium, whose blue dome can be glimpsed through the redwood grove that shelters it.

While I have posted before about the installation of remarkable new technology in the planetarium I'm privileged to work in, I have not until now posted any images of what that technology can produce. In part, that has been due to the imaging challenges involved: the planetarium simulates the night sky in all ways, including darkness. That and the odd geometry involved in shooting photos of images projected on a hemisphere was enough to keep me from learning how to manage it for a while.

But I'm starting to be able to do it.

Mars and Phobos, seen from about a hundred kilometers above the latter, as they would have been seen at about 2pm, Pacific Daylight Time, this afternoon.

The "Two Skies" part of this post's title refers to the two sky simulation systems at the heart of the planetarium's renovation. I refer to them as the "space simulator" (SkySkan's all-digital system) and the "sky simulator" (Konica-Minolta's new-generation Infinium-S optical-mechanical system.) Each does a different job in magnificent fashion.

The Space Simulator

SkySkan's digital system provides me with the ability to "fly" through a huge database which includes, among much else, accurate information about the locations, angles of illumination, and orientation of thousands of solar system objects at any time within several thousand years of now, both forward and backward in time.

Jupiter's inner satellites' orbital paths and their locations at about 2:15, PDT, June 25.

It's important to note that the images in this post are actual photographs of part of the inside of a planetarium dome, not screen captures from a computer monitor. Unless otherwise noted, each of the images here cover the same area of the dome, a slice about 25 feet wide and commensurately high. The dome itself is a hemisphere 50 feet in diameter, and the camera's location was about 35 feet from the point of aim. This means that, while not particularly evident, the edges and top of the frame are fairly significantly closer to the camera than the center and bottom (which is just above the bottom rim of the dome.)

Simulated Ganymede with Jupiter in the background, June 25, 2009. This and the other "space simulator" images in this post are 20-second exposures with a Nikon D70 at ISO 400 using an 18mm lens stopped to f/8.

It is also important to note that the images here are not frames from a movie. The operator of the system is completely free to specify location, time, and direction of view of the "camera." Navigation is remarkably simple -- but what goes on under the surface isn't. The database is manipulated by a stack of ten quad-core Intel computers. One computer orchestrates the other nine, one is dedicated to managing sound for applications that have it, and the other eight each manage one "channel." Each visual channel is projected on a "tile" that covers 1/8 of the dome, and the ensemble is remarkably seamless in appearance. Projection is done by a pair of cinema theater grade Sony digital projectors with special optics, each of which handles four of the channels.

Looking back toward the Sun from Saturn on June 25, 2009.

The detail and accuracy in the database (which is frequently updated by SkySkan) is astonishing -- and very, very useful as a teaching tool. The above image of Saturn, for example, shows some interesting things in the shadow of the planet across the rings toward us. (Click on the image to see it larger.) Notice that you can see some stars through the rings in the shadow? That's not a mistake: there are places in the rings where the material is thin enough for that to happen... and places where it isn't. If we shift our position a little down and to the right...


... the two stars that shone brightly through the "Cassini Division" in the previous view are now blocked by the more richly-populated A Ring (the brightest component of the system in reflected sunlight.)

View toward the center of the Milky Way Galaxy. If you click on the above image, you'll see that all of the stars have color. Those colors (based on the stars' spectral types) are not usually evident to most planetarium patrons except for the very brightest ones -- as is the case in the real sky -- but they're there, nonetheless.

The Sky Simulator

The other system, the Konica-Minolta Infinium-S, can't fly us around the solar system, but it provides a much more realistic simulation of the night sky as seen from right here on Earth.

The optical-mechanical projector at the heart of the Konica-Minolta system is an engineering marvel, and I don't have a clue as to how it performs its magic.

Until very recently, all planetarium projectors achieved different brightnesses for their projected stars by a very simple, but very innacurate, method for all but the very brightest ones: by having the "stars" be different sizes: bigger "star" --> brighter "star." That's also the way that the digital Space Simulator that we've been looking at so far does the trick.

But that's not the way the real universe looks.

Unless your eyesight is really bad, the stars in the real sky all look the same size: pinpoints of light. Their brightness differences are entirely due to different intensities. That's the heart of why planetarium simulations never looked very real to me: different brightnesses were achieved by different sizes of images which all had the same surface brightness.

Here's an expanded view of Canis Major in the space simulator system, the one that does brightnesses the old-fashioned way:


... and here, to the same scale, the constellation Lyra in the Konica-Minolta sky simulator system:


If you click on the above image, you'll see that all of the stars have exactly the same size, no matter what their brightness -- just the way the stars appear in the real sky. (As an added bit of realism, the 20 brightest stars in the Konica-Minolta sky can be made to twinkle!)

The realism of the sky simulator system is such that I still haven't figured out how to capture its view very well with my camera. Here's a two-minute exposure toward the Great Summer Triangle at f/8:

(the lights at the bottom are inside the projector itself.) And here's an eight-minute exposure:

I was baffled by the red glow here: to my eye, the dome was pitch black except for the pinpoints of the stars' images.

But the camera doesn't have the same spectral sensitivity that our eyes, do, evidently. Where the faint red in this long time-exposure came from is evident in this trial shot at a lower angle for the space-simulator system:

Saturn, its rings, and some of its satellites' orbital paths.

See the bright red rectangle near the bottom about 3/4 of the way from left to right? That's an infrared broadcast station for the planetarium's assistive listening device system. Its radiation is invisible to the human eye -- but not to the D70's sensor! (This was the first time that I realized that my old digital camera records a significant amount of infrared. That's a little disconcerting.) So the pervasive red glow in the very-long time exposures is IR from these devices reflected from the dome.

The next time I try this, I'll turn off the ALD system... but I ran out of time this afternoon.

The cities shine like stars.

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Almost as Nice as Seeing Stars in Little Girls' Eyes...

... is having the wherewithal to put them there.

Setting up a little planetarium show for the girls, Sunday, March 22nd, 2009.
Please, PLEASE, click on the images to see larger, better versions.

This past weekend was one of those on which Ft. Harrington was blessed by a visit from some of our East Bay family. Adam and Lynda brought Grace-the-Granddaughter and her friend Scout down on Saturday and stayed in Boulder Creek until early Sunday afternoon. We figured that Grace and Scout are old enough now to enjoy a session in Granddad's planetarium, so we arranged a private time in the facility for them and other family and close friends. The planetarium is on the route back from Boulder Creek to the East Bay, so it was a convenient place for several of our friends and family to meet on Sunday afternoon.

Saturday evening: "Yes, Emma, you may kiss my hand." Grace now thoroughly understands the special relationship Cavalier King Charles Spaniels have with young humans.

Saturday evening: Grace's friend, Scout, absolutely radiates joy. (She evidently has also radiated away her incisors recently.) Here, she cavorts with the usually-elegant Alnitak. (Guinness, at lower-right, displays the only highly-reflective part of his now-adult body.)

On Sunday morning, I trekked down from Boulder Creek to the planetarium ahead of everyone else, giving myself time to set some things up -- including the above welcoming projection on the dome's simulated daytime sky...

... and it was a big hit with the girls!

Sherwood's workstation.

In addition to Adam, Lynda, Grace, Scout, Diane, and me, a number of other close friends and family joined us in the Planetarium (including Scout's Mom, Dad, and brother, and Grace's mom). My great good friend Paul, the only other full-time astronomy teacher at my college, joined us, too, giving up a good chunk of his rare free time to play with the Harringtons. So, of course, I put him to work.

I still don't have the expertise necessary to photograph planetarium shows as they unfold -- and, actually, I wouldn't have had time to do it anyway. But here's a short rundown of what we did and saw in the Magic Chamber:

Part I: We used the digital planetarium system (data housed in a bank of ten quad-core pc's) to fly around the Solar System. Particular points of visitation included Earth, the Moon, Mars (and Phobos), and Jupiter (and Io.) [*]

Part II: We used the spectacular Konica-Minolta Infinium-S new-generation optical-mechanical star projector (the blue ball in two of the above photos) to tour the nighttime sky as it would be after dark this evening in Northern California, urging everyone to go outside tonight and see it in the best planetarium of all: the real sky. Paul guided this part of the program with his typical good humor and expertise -- despite the fact that I hadn't warned him ahead of time that he'd be doing it!

Part III: We used the Planetarium's digital system to screen a short hemispherical-projection, immersive animation about what it takes to be an astronaut.

I'll depend on Adam to tell you in comments about whether or not everybody enjoyed the show. Meanwhile, I'll let the smiles in the next photo -- taken after we were done -- give you a little clue!

Most of our guests had left by the time this was taken, but we got most of the family members in! Front: Grace and Scout. Lynda is kneeling behind Scout. Back row: Scout's mom, Robin, rests her hand on Scout's brother Turtle's shoulder, two of Scout's neighbors (whose names I didn't write down!), Grace's mom Adrianne, Adam, me, Diane.

(Lucile, Ryan, Christel, and Casey: sorry you couldn't come! But there will be plenty of chances for a next time.)

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[* Because there have been requests for it, here's the playlist of the music I used for the Solar System flyaround segments:

Introduction (instrumental): Pastures New by Nickel Creek (Album: "Nickel Creek")

... and a HUGE shout-out to Dann Todd for turning me on to Nickel Creek!

To the Moon and back: Standing on the Moon by the Grateful Dead (Album: "Built to Last")
Out to 30AU: Reasons Why by Nickel Creek (Album: "Nickel Creek")
Mars: Boadicea by Enya (Album: "Paint the Sky")
Jupiter: Mo Ghile Mear by the Chieftains with Sting (Album: "The Essential Chieftains")
Jupiter back to Earth and to California: Heartland by Celtic Thunder (Album: "Celtic Thunder: Act Two")]

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Okay, NOW It's Full of Stars!

The first Infinium-S in operation outside Japan, April 20, 2007, DeAnza College, Cupertino, California

Today marked the first (well, sort of) "official" use of the new planetarium projector: an initial training session for those of us who will be operating it by the Konica-Minolta staff. Installation and fine-tuning of the device is very nearly finished, and training in its use, programming, and upkeep will continue over the next four days.

Initial gathering at the control console.

I should note that the photos in this post are not quite of the quality that I've tried to maintain in this blog, and with good reason. Even in the lighted portions of the training, the ambient light in the planetarium dome was very dim. Not wanting to use flash, that meant long exposure times and noise-ish images. Still, better views can be had by clicking on any image.

View from the front of the theater toward the control area at rear.

The image above really has to be seen at larger size (by clicking on it) to appreciate. It shows the projector (at right) in operation. It was being turned as the exposure was made, and star trails can be seen on the dome.

Ken Hawthorn (Community Ed) and Marek Cichanski (Geology faculty) work the controls.

It is hard to convey in words or pictures how realistic (and awe-inspiring) the sky that's provided by the Infinium-S system is. Star images are sharp and tiny, the Milky Way is simulated by a quarter of a million individual points of light, the 21 brightest stars can be made to scintillate (twinkle) realistically, and many "deep sky" objects -- galaxies and star clusters -- are rendered sufficiently accurately that viewing them through binoculars isn't a thoroughly ludicrous thing to do.

By looking closely at star images at the horizon, I estimate that the largest of them are about an eighth of an inch across. As seen from a typical audience member's distance, about 30 feet, an eighth of an inch subtends an angle of about 1 1/4 arcminutes, which is close to normal human eyesight limiting resolution. It's also three to four times finer resolution than we had with the previous projector.

Ken Hawthorn on the flight deck.

Computer control of virtually every aspect of the sky simulation allows not only a greater range of WOW stuff (as it's called in the specialized technical jargon of planetaria), but also a smaller control console. The controls for the old MS-15 took up five times this much space, easily.

Trainees and their trainers on April 20th.

Our trainers today from Konica-Minolta were Shu (kneeling) and Ume (at far right). The nine trainees were from the DeAnza faculty and Community Education's planetarium staff. The planetarium facility is operated by Community Ed, but College classes are held in it for seven hours per day, Mondays through Thursdays. It's a remarkably amicable symbiosis between two very much administratively separate arms of the College.

The two men in this picture who live in the Santa Cruz Mountains -- Planetarium Director Karl von Ahnen and I -- are the ones with the beards. I'm the one with hair on top of my head, too.

There is something of an aberration about this picture, by the way. Notice that, aside from our Japanese trainers, everybody else in the picture is a white male. This is highly unusual for DeAnza, and I'm not quite sure why the group worked out this way (I hadn't noticed until I just now put the picture into the draft of this post.) It warrants some thought, but I don't think it really amounts to anything more than small-number statistics. Our "bosses" (the Deans of Physical Science and of Community Ed) are both women, for example, and their bosses (at the VP level) are, as well. To see a more typical-looking group at DeAnza, take a look at this little slide show of my Division's March meeting.

Cooper investigates the Infinium-S manual.

Cooper expresses his opinion of the quality of the translation.

Previous posts about the Planetarium renovation:

My God, It's Full of Seats!
and
Giddy with Anticipation

"My God, It's Full of... Seats!"

Sorry, Dave... but the seats are a good start, anyway. It'll be full of stars pretty soon.

My last entry about the progress of the DeAnza Planetarium renovation was ten days ago. At that time, it didn't have any seats. Ten days from today, the spring quarter begins -- and eight hours a day of classes will be taught in the facility -- for the first time in more than a year -- starting then.

Having seats for the students would be a good thing, so I'm glad to see them.

There are 139 seats in the new configuration (there used to be 167 in the old, all-center facing orientation.) This smaller number of seats, all facing the same way, allows for a "stage" area for lectures or other kinds of performances.

We can have them all face the same direction because, unlike the MS-15, the Infinium-S can be rotated azimuthally to bring any part of the sky into front-view. It will be easy to fall under the illusion that the room is rotating, I'm sure.

The Infinium-S machine now looks much more like it will in use than it did ten days ago, too. The innards of the starball are no longer left exposed, and the peninsula (at front-left) for the wanderers is more fully enclosed. (All photos can be seen in larger format by clicking on them.)

The starball. This part of the machine is mounted on a scissors-lift "elevator" and can be lowered about three feet for clearer sight lines in lectures, etc., when it's not in use.

The control area is rounding into shape now, too. Most of the furniture is now in place, including computer cabinetry and auxiliary desks. There will be two or three more flat-panel monitors working when everything is functioning fully, and those monitors will be specially-dimmable to extremely low brightness.

Even though classes are scheduled in the planetarium for the spring quarter, we won't be simulating the sky in them for at least the first month. There is still a lot of fine-tuning to be done by the Minolta team (they'll work 10pm to wee hours once classes are taking up most of the day hours), and training of the staff (including yours truly) will take a while. Our large astronomy classes have been taking up space in the College's lecture halls for more than a year now, though, causing headaches for the classroom schedulers, and they want us to move back into the planetarium at the earliest opportunity, whether our fancy projector is fully-functional yet or not.


... but it has some great assets besides the Infinium-S. Above is the instructors' cart (you can't see the wheels). The cart contains an "Elmo" digital visualizer, which can feed either transparencies or opaque media such as writing on paper through the video-projection system. This replaces black- or white-boards for notes, etc. It also contains a new computer with a T1 internet connection which, likewise, can be piped to video. The main classroom video projector is a very-high resolution, very bright (I don't have the specs for either resolution or lumens in front of me, but I've seen it in action -- even across the 50-foot throw from under the back of the dome to the front, it's plenty bright enough to have the house lights up so students can take notes easily while watching whatever is on the "screen," i.e. the ~20-ft. wide section of the dome onto which the video projects.)

Other goodies for classroom use that you can't see are high-end DVD and videotape players and a very fine audio-mixing board.

As the sign on the wall behind the cart says, there will also be an "assistive listening system" available on request for patrons or students who need it. I haven't seen this yet, but it is necessary, since closed-captioning during planetarium shows is not a technology that we have yet, and, of course, the College's signers can't work in the dark.

All photos in this post by S. Harrington, March 30th, 2007.

Standard disclaimer for any entries about my employers, DeAnza College: I don't speak for them, they don't speak for me, they pay me.

Giddy with Anticipation

Disclaimer for this and anything I post that involves my employer, DeAnza College: I don't speak for them, they don't speak for me, they pay me. All photos by me unless otherwise noted.

I get to play with some of the coolest toys.

The above photo shows a silhouette of the Minolta MS-15 star projector in the DeAnza College Planetarium. More precisely, it was in the DeAnza Planetarium until just about a year ago.

The MS-15 was Minolta's first planetarium in an American facility (installed in 1970), and represented the company's serious entry into a tiny, specialized, expensive market dominated before that by legendary names like Spitz and Zeiss. The planetarium branch of Minolta (now Konica Minolta) did well after that and is now a revered name in the niche -- just like Spitz and Zeiss (and Goto).

The DeAnza Planetarium and its revolutionary MS-15 was inaugurated with great fanfare in '70, and rightly so. It was then -- and, I think, today remains -- the largest planetarium in the western U.S. that is operated by a Community College, and has provided a great indoor astronomical experience for hundreds of thousands of schoolchildren and college students for the past generation.

The MS-15 near the end of its days.

Problem was, it got old. Really, really old. The MS-15's projected useful lifetime in 1970 was 15 years... but it was kept working by innovation, desperation, magic, and duct tape for more than twice that. By the time it was pulled down in 2006, it had even lost Arcturus, and was taking more of the technical director's (Karl von Ahnen's) time in upkeep and cajoling than his actual shows were.

So, out with the old, in with the new:

Planetarium Director Karl von Ahnen (left) eyeballs progress on March 20th, 2007.

The planetarium is nearing the end of a year-and-a-half thorough renovation, inside and out. The heart of the renovation is its new star (and planet) projector -- a spiffy-new, state-of-the-art, Konica Minolta Infinium S star machine. Our Infinium, like the old MS-15, will be the first of its generation of Minolta machines installed anywhere outside of Japan.

Installation, fine-tuning, and -- especially -- training will take several more months before the facility is ready to swing into full operation. Meanwhile, it will see limited use for College classes and some school shows during the spring and summer quarters. The official grand opening will be in the Fall.

When fully-operational, the facility's capabilities will be stunning, and I'll have more posts as time goes on to detail them. For the time being, I'll just mention that the Milky Way will actually be a quarter of a million individual points of light instead of a ghostly smear, that some nebulae and galaxies will be projected with sufficient resolution and realism that one can actually use binoculars inside our 50-foot dome to see them better, and that the positions of the planets (for any date and time) can be shown as seen from any of them, not just Earth!

For more of the astonishing capabilities of the Infinium S, please click here to see Karl von Ahnen's "top ten list" style rundown.

A member of the Minolta installation team aligns the Infinium-S horizontal axis on March 20th. The team of five technicians will be here for several more weeks, finishing and fine-tuning the installation of hardware and software... and setting up a training regime for the wetware (us operator types.)

Dry but possibly necessary background bureaucratic information: The planetarium is not operated by DeAnza College's Physical Sciences, Mathematics, and Engineering Division (of which my Astronomy Department is part.) It is operated by a fiscally self-sustaining unit of the College called "Community Education," under the very capable direction of Dr. Caron Blinick, a former English Professor. Dean Blinick and I (as head of DeAnza's academic Astronomy department) coordinate the facility's use, balancing needs of instruction, community outreach, and Community Ed's mandate to balance its books. I like the arrangement -- there's no way in the world or out of it that I would want the responsibility of scheduling grade schools' field trips, for example -- but.. well, let's just say that it's a good thing that we all like each other and leave it at that.

Photos for the time being:

If you've ever remodeled a kitchen or a bathroom, you know how strong the urge is to make something look different on the outside, too, just... well... just because. Same goes for remodeling your star projector. Here's how the planetarium dome looked for years:

... and here's how it looks now:

Photo taken on March 9th, 2007. The switch of dome color from red to blue was not based on political considerations. Really.

Sherwood ponders a learning curve, March 20th. Photo by Karl von Ahnen.

When completely installed, the machine will have a very sleek look. Today, everything's exposed (sort of like Darth Vader without his helmet.) The gizmos in the foreground in the above picture are for projecting the positions of the planets, Sun, Moon, and programmable transient events (like comets or near-earth asteroids) against the background of the stars. The stars themselves (and other things that don't appear to move relative to one another, like galaxies, nebulae, and other deep-space objects) are the job of the star-ball above my head. Both parts are equally vital to a planetarium's working -- and contribute about equally to a projector's cost. That cost, retail, for this machine would be about $2 million, but don't expect to find one on the shelf at WalMart.

Vader's helmet (the shell for the starball). Caution, indeed. This shell is individually fabricated from the aluminum casting on up. Dents are not welcome.

My future workstation. This little set of computer controls replaces the five times as much control surface (conservatively speaking) that was needed to operate the much more primitive MS-15.

If you've been interested enough to read this far, please visit Karl von Ahnen's much more extensive account of the renovation/resurgence of the planetarium.

(Karl is a delight in all ways except one: accompanying him on commercial air travel is an extreme exercise of one's patience. No fault of his, really, since he's had it since the '60's -- but that beard invariably attracts a great deal of attention from TSA droids. Thank God he doesn't wear a turban. Karl treats it all with great equanimity, but the rest of us have been known to fume.)