Sunday, May 03, 2009
The Quietest Revolution
What’s had the most earth-shattering effect on amateur astronomy over the last decade and a half or so, muchachos? The near total acceptance and domination of goto, of course. These days just about everybody is doing the robo-scope thing; not just CAT users but even the big dob guys. There’s certainly no doubt about the impact go-to has had on every facet of astronomy, from what and how we observe to the way we initiate novices into the avocation.
But it has not been the only Big Deal. Something potentially almost as far-reaching in effect has been going on under most of our noses for about the same period of time. Brothers and sisters, I am talking video astronomy. As the years roll on, I believe that it—the use of sensitive video cameras for deep sky observing—may have as much or more influence on the future shape of our hobby as go-to has.
I’ve been interested in applying video to astronomy ever since the start of the 1980s when prices on cameras and recorders began to come down and quality began to go up. My first go involved a Sony black and white camera, a “closed circuit” camera, equipped with a vidicon-tube sensor (pre CCD/CMOS) my brother had acquired along with a used ¾-inch U-matic VCR. I have no idea 30 years later what he wanted with the U-matic (the professional equivalent of VHS), but the important thing was he didn’t need the camera that came with it and happily turned it over to me after a while. What I wanted to do was try hooking it to my C8. I acquired a “C” (the standard video/movie camera lens mount) to “T” adapter, placed the Sony on the back of the C8 at prime focus position, and hoped for the best.
The results were not mind-blowing, that’s for certain. The Sony did a fair job on the Moon, especially with the aid of an eyepiece projection adapter, and even revealed that Saturn had rings (they usually looked more like Galileo’s “ears”). Still, the potential was there, I was convinced of that. All that was needed was More Better Gooder camera-wise.
That came in due time in the form of one of the early 8-mm camcorders (again a Sony, and again courtesy of my brother). Since the lens wasn’t removable, I used this color camera in afocal fashion, placing it on a tripod next to my Dob’s eyepiece, or, more frequently, just hand holding it and pointing it into a low power ocular. Crude, yeah, but the results I got still surprise me.
Unk ain't won too many photo contests, but this was one! |
As Internet amateur astronomy bloomed to life in in the mid 90s, I soon found the late, lamented "newsgroup" (like a prehistoric Yahoogroup, y'all) sci.astro.amateur, and that led to the discovery that I wasn’t the only person doing video astronomy. Before long, a few of us, led by Jim Ferreira, banded together to form an email discussion group, “Videoastro” to talk over the new art we was calling “astro-videography.”
First order of bidness for our new Egroup (soon to become a Yahoogroup) was equipment. Camcorders showed what was possible, but we needed better: inexpensive cameras with removable lenses and more sensitivity. If we were to have a prayer of competing with film, we knew we’d have to move beyond afocal camcorders. That move was shortly made possible by a small Texas company, Supercircuits, who hawked video surveillance gear that appealed to private dicks chasing adulterous couples.
Luckily our requirements were about the same—cheap, low-light cameras in small packages—and Supercircuit’s video cameras filled the bill just right. One in particular, the now legendary PC23C, seemed perfect. Though it was black and white only, it was better than a camcorder on anything we pointed it at. Dump the resulting VHS frames to a computer (with a primitive Snappy frame grabber) and stack ‘em with this new-fangled program Astrostack, and we were there—we thought, anyhow. The images we were achieving of the Moon and planets—especially the planets—were better than what the average amateur could produce with film.
For a while, Videoastro was a going concern. Enough amateurs heard what we were doing and glommed onto Supercircuits PC23Cs (which cost about 75 bucks) that the company was soon, believe it or not, touting astronomy as an application for their vidcams. Naturally, we was never satisfied, and were soon moving beyond simple mods to our PC23’s to disable their automatic gain circuits for better exposures of Jupiter and Saturn and were dreaming of using ‘em on the deep sky. Somehow. Sure, THEY, the experts, assured us video cameras with their 30-frames-per-second exposures would never be sensitive enough for faint objects, but that didn’t stop us.
The beloved Supercircuits PC-23C |
As the 1990s began to wind down, our group of stalwart video astronomers began to change. Our focus on the Solar System began to wane. That was because another group of folks, those obsessed with using those “kinda video cameras,” the webcams, with their telescopes had shown their little cameras coupled with Registax would blow PC23s (and film cameras) out of the water on the Moon and planets. That would probably have spelled the end for the Videoastro group but for (in the U.S.) the coming to prominence of a company called "Adirondack Video Astronomy" (now just "Adirondack Astronomy"), What these folks did was deliver the deep sky dream for us by introducing a camera, the Stellacam, that gave us what we needed to explore the larger universe with video.
Actually, a few creative amateurs in the U.S. and Europe had already been experimenting with deep sky capable video cameras, most notably the Watec and the Mintron cams, some time before the Stellacam appeared. It was John Cordiale at Adirondack that brought deep sky video from “experimental” to “off-the-shelf” for most American amateurs, however.
John and his compadres had been in the video game for a few years previously, producing some high-quality black and white and color cameras for Solar System imaging that were far more capable than our humble PC23Cs. The coup, though, was the introduction of the original Stellacam and, shortly thereafter, the improved Stellacam EX. The remarkable thing about the EX was not that it employed a sensitive CCD chip (0.00005 lux), but that we finally had what we knew needed for deep sky video, the ability to shoot longer exposures, up to nearly 5 seconds. 5-seconds doesn't sound long, I know, but coupled with the chip’s high sensitivity, deep sky objects, especially the bright Messiers, just exploded onto our monitors. As I found out at ALCON 2003.
My Saturn with a PC-23C. Still not half bad if you ask me. |
You can read an account of Unk’s and Miss Dorothy’s adventures at the event here, but what this has to do with our current subject is that it was the first time I was exposed to the wonders of deep sky video astronomy outside the yak-groups on the Internet. When I say it was a great convention, I mean it. And I don’t just mean all the free drinks at the Nashville Embassy Suites’ happy hour. I mean speakers like Richard Berry and Kelly Beatty and Don Parker and Ron Wodaski. I gotta say, though, that what most piqued my interest was the talk given by Lonnie Putterbaugh on deep sky video imaging. Lonnie’s talk, though, excellent as it was, was not what converted me to the Stellacam, it was the star party we had on Friday night after the last paper session.
On the face of it, Nashville’s Airport Embassy Suites was the last place you’d expect to do DSO viewing. We are talking pink sky purty much from horizon to horizon, and despite the fact that the hotel management graciously turned off the parking lot lights for the duration of our star party, I thought we wouldn’t see much more than the near full moon and a couple of smudges, video or no video.
Ha! Once Lonnie got his LX200 10-inch and Stellacam EX cranking I soon got an edumacation as to what deep sky video could do. First target was the Omega Nebula, M17. Smudge? Not hardly, campers. Not only was the Swan shape evident, so were the dark lanes running through the “body” and the dim detached patches that usually defeat the eye in even large scopes from dark sites. M22? Plenty of stars despite a Moon just a little ways away. M13: same-same. M51? We have spiral structure, Houston.
Mallincam + Newt, but I usually put it on an SCT, natch. |
But did I immediately run out and buy a Stellacam? No. At the time I was embroiled in writing the book that would become The Urban Astronomer’s Guide. But not just that. I heard through the grapevine that Adirondack Videoastronomy was getting ready to come out with a new camera they were calling the Stellacam II, which would feature a maximum exposure time twice as long as that of the EX, almost 10-seconds. The new one would have cleaner, less noisy video output as well. I also learned AVA was no longer the only game in town for deep sky video. A dude up in Canada, Rock Mallin, was beginning to offer Adirondack some stiff competition.
So I held back. Hemmed and hawed. Should I get the Stellacam or the Mallincam? Was a vidcam really for me at all, or should I just concentrate on larnin' to use a REAL CCD camera? Could I be convinced to open my dusty and moth-eaten wallet to the tune of near 1000 George Washingtons?
Eventually, I did screw my courage to the sticking place, in 2005, and ordered a Stellacam II from AVA. Why not the Mallincam? Despite the good things I was hearing about the MC, the Stellacam was a known quantity—I’d at least seen a couple of the cameras in action. And, more importantly, I liked the size of the Stellacam which, as in the image above, is a smallish cube. I figgered its Watec style case would be just the thing for use with my NexStar 11 in alt-az mode. I ort to be able to track near to the zenith without worrying about the camera bumping into the base as I’d be with the more “traditional” shape of the Mintron-like Mallincam.
After a not short but not long wait, the SCII was at Chaos Manor South, and my little daughter Lizbeth and I were loading up for a jaunt to the Possum Swamp Astronomical Society's heavily light polluted in-town observing site. Getting the camera going turned out to be almost painless. Certainly I lost far less of my hairline than I did the first night out with my old Starlight Xpress MX516 CCD.
Setup was easy. First order of bidness was putting a Meade f/3.3 reducer on the C11. The small size of vidcam chips, then and now, means that if you are to obtain a field wide enough to sensibly frame DSOs and keep ‘em bright, you want the focal length at about 900-mm or less. At this image scale, most things I want to look at are nicely sized on the screen. M51 fills the field, many planetaries are big enough to show detail, but even the Orion Nebula is more-or-less squeezed into place.
My first, humble deep sky video image, M57. |
Once we had the scope aligned and all the connections in place, Lizbeth and I inserted the SCII into the C11’s visual back by means of the camera’s 1.25-inch nosepiece (which can be unscrewed to reveal C-type lens mount threads). We focused on the bright go-to alignment star the scope was still pointed at, adjusting first with the camera in real-time 1/30th-second mode. When the star was as small as we could get it, we upped the exposure to a couple of seconds and sharpened up on dimmer field stars. Setting the integration time was real easy with the camera’s simple wired remote. Just turn a little click-knob until you landed on whichever one of the 10 exposure settings ranging from 1/30-second to 10-seconds floated your boat. In addition to integration time, there was a dial for “gain,” and a slide switch to increase “gamma” (contrast). It did take a little experimenting to discover what worked best for different types of objects and at the different intensities of background sky glow we suffered from horizon to zenith.
Once we had a handle on these things, though, the Stellacam jus’ started cookin'. If I needed to be more convinced about the practicality of deep sky video observing, I was more convinced. The Stellacam/C11 left the 18-inch Dob set up next to us in the dust. There was just no contest. The 18 showed the Saturn Nebula nicely as a slightly elongated blob, but the C11 gave us the ansae, the “rings,” when seeing steadied down. M57, the Ring Nebula, was cool in the Dobsonian, but that scope didn’t have a prayer of picking up the central star given the bright skies and poor seeing. The C11-Stellacam easily showed that visually challenging sparkler.
Most impressive of all, perhaps, was the user friendliness and simplicity of the Stellacam. 13-year-old Lizbeth basically took over the controls as soon as I’d sussed-out basic operation: “Here’s the Great Bird of the Galaxy, Daddy!” Up came M42, and, with a little tweaking by Lizbeth, it was looking good. “How about M82? I’m gonna call it the Exploding Cigar Galaxy!” Cool, way cool. Maybe the coolest thing? We’d dragged an old VCR out with us, and I can, if I want, go back and look at Lizbeth’s deep sky picks (now long-since transferred to DVD) from that memorable night any time I want.
Going deep with a Stellacam. |
Which doesn't mean a video camera will replace the CCD camera. The larger chips of still CCD cameras (the chips in video cameras are, of course, CCDs too) mean they are far more suited for imaging large objects. Yes, a vidcam can pull in the California Nebula if you can get the focal length down, but that ain’t easy without going to camera lenses or very short, small refractors.
That’s hardly the only way an SBIG or Apogee will pull ahead of a Mallincam or Stellacam. In addition to larger chips, most modern CCD cameras are far less noisy. Images look cleaner because they are cleaner. Once of the biggest drawbacks for deep sky video cameras used to be hot pixels. As winter became spring, I noticed my Stellacam began picking up more stars than she used to. I also noticed that these “stars” were not moving when I slewed the scope. By August, I was “discovering” lots of new “open clusters.”
Yep, crank up the integration time and gain, and thermal noise becomes a real problem. But not a deal-breaker. Even on the hottest evenings (down here that can easily be in the mid 80s), thermal noise is not even close to obscuring my targets or making my images truly ugly. Still don’t sound too promising? Don’t worry. You don’t have to move to Yankeeland to banish these false stars. All current Mallincams and Stellacams are equipped with Peltier coolers either as standard equipment or as an option.
I began collecting supernovae with the Stellacam. |
There’s also the ease with which video makes it possible to share the sky’s wonders with your friends (and with the lay public). I still relish the winter evening when the C11 and I were able to reveal the elusive Horsehead Nebula to my fellow club members, most of whom had never seen it save for pictures in books and stills on the dang I-net. Yeah, if somebody had had a 25-inch out at our good but not perfect site they might—might—barely have seen B33 with it, but they sure as hell wouldn’t have seen the shape, form, and substance on view with the Stellacam.
“But Uncle Rod, but Uncle Rod, looking at an object on a video screen is not like the PURE experience of seeing it through an eyepiece.” Yep. No doubt about that, Skeezix. And yet…and yet…as I continue to do video and have also begun to do more visual observing than I have in recent years, I’ve come to the conclusion that in some ways the experience is more similar than you’d think. For one thing, you are looking at an image that is semi-live. Yeah, it’s refreshing every 10-seconds, but that’s not the feel. The feel is that you are seeing the Nasty Nag Now.
Also, and very importantly, the look of objects on video is much more similar to what the eye delivers than what anything but the most laboriously processed CCD images yield. M42, for example, shows plenty, and I do mean plenty of nebulosity. As Miss Lizbeth noted, it spreads its wings like some huge bird. Even so, and unlike in most CCD images, the Trapezium and the many tiny stars embedded in the Great Bird’s breast shine out clearly and fiercely. The interior portion is not a burned-out mess. M13 is tricked out with zillions of outlier stars, but stars are also easy to pick out in its core. The middle of the Great Cluster is not merely a white blob.
As you’ve no doubt gathered from the above, I mostly use the Stellacam to produce video. I view objects in real time on my DVD player’s small screen and record ‘em on DVD for later examination at home (A 100 buck DVD recorder, an AC inverter, and an inexpensive trolling motor—err, “deep cycle marine battery”—and I can observe from the most primitive sites). But, yes, I do occasionally produce still images. That’s easy enough. I use a freeware utility called “FlasKMPEG” to convert my DVD (mpeg) sequences to .avi files and then I stack ‘em with Registax.
The Mallincam picked up far more nebulosity than I'd expected. |
So where is Unk goin’ next with video? For now, I’m keeping on truckin' with my obsolete and discontinued Stellacam II. It works as well as ever, and the good folk at Adirondack have been super, fixing the single problem I’ve experienced (a punk powersupply did bad things to my cam—wouldn’t you know it—in the middle of the 2005 Chiefland Star Party) swiftly and without complaint.
The AVA gang has had a replacement of the SCII available for some time, the Stellacam III. Priced comparably to what I paid for my II four years ago, the SCIII offers, amongst other improvements—which include an optional Peltier cooler—one huge innovation: you can expose for as long as you want. One of the beauties of video is that you can leave your guide scope home and set up in alt-az mode on your scope, making things really easyonya. That’s made possible by the 10-second-range exposures that were heretofore the max for the Stellacams. Still, I can see going to 15-seconds, 30-seconds, or even a wee bit more without giving up round stars to any great degree, and I am a-wondering what I might pull in with 3x the exposure available to me now.
The Stellacam III sounds great—I ain’t seen one in action yet—but I’d be fibbing if I didn’t say most folks think “Mallincam,” not “Stellacam” when video comes up for discussion these days. One reason is that Rock Mallin and his distributor (and my friend), Jack Huerkamp, have not hid their light under a bushel. You’ll find them posting frequently in places where video observers gather, like the time-honored and still alive Videoastro group. I don’t know that I’ve ever seen a missive from John Cordiale and company there. But that ain’t the only reason.
Rock has continued to push the video camera forward. His current cams have onboard coolin’ as a standard feature, and, in a real coup, Mallin was first out the gate with a color camera. How do the Mallincams compare to the Stellacams? The black and white cameras are fairly similar. No, you cannot expose for as long as you like with the Mallin Hyper Plus camera; it is limited to 56 seconds. As I mentioned, though, go much above 30-seconds and you will begin to lose some of the video advantage. Also, the Mallincams automatically click off their longer exposures. If you are doing long exposures with the Stellacam III, you will have to manually initiate and end them, which don’t sound like fun to me. Mallin also has quite a few more accessories available for his cams, including a focal reducer.
The earliest Mallincams brought us Peltier cooling. |
Wherever I go from here with video, it’s been quite a trip and one I wouldn’t have missed. I think it’s just gonna get better. No, deep sky video is still not something the amateur community has fully embraced, but in the last few years it has become the norm to find at least one video setup running at just about any medium-sized star party. The deep sky video word is starting to trickle out to the larger amateur community.
In these trying economic times, most folks are gonna think twice before spending the money and fuel for a week under dark Texas Star Party skies, nice as that may be. As they begin to realize a Stellacam or Mallincam can make the local club site or even the backyard into their own personal Prude Ranch, and as AVA and Mallincam advance the art further, I expect video to not only become more popular but to maybe even surpass the popularity of CCD cameras for the rank and file. Me? There are some spring Hickson’s I need to catch, muchachos so I’ll sign off. See y’all in the funny papers—and on Videoastro.
Next Time: My Old Friend...
Comments:
<< Home
Hey Rod! Really nice piece, and keeper for sure. I've been hankerin' for a vid cam and you've given me what I need to know.
Thanks, and Clear Skies!
Thanks, and Clear Skies!
Hey Unk,
Do you ever use your Stellacam with your ETX?
Reason I ask is because I have an ETX125 and a de-forked 10" LX200 on an Atlas EQG. The ETX is much easier to setup than the LX200 (even after you clued me in to your quicker polar scope setup routine on the EQG - thanks BTW!).
The little ETX is great on planets & brighter objects, but doesn't really do much for dimmer DSO in my light polluted back yard. I know that the smaller aperture won't grab as much light as my big cat but if a video cam like the Stella or Mallin can show me more than an eyepiece can in my ETX125, combined with the easy setup, I might just consider one. I guess I'm really just trying to figure a way to see more, more often.
What do you think?
Best Regards,
SC
Do you ever use your Stellacam with your ETX?
Reason I ask is because I have an ETX125 and a de-forked 10" LX200 on an Atlas EQG. The ETX is much easier to setup than the LX200 (even after you clued me in to your quicker polar scope setup routine on the EQG - thanks BTW!).
The little ETX is great on planets & brighter objects, but doesn't really do much for dimmer DSO in my light polluted back yard. I know that the smaller aperture won't grab as much light as my big cat but if a video cam like the Stella or Mallin can show me more than an eyepiece can in my ETX125, combined with the easy setup, I might just consider one. I guess I'm really just trying to figure a way to see more, more often.
What do you think?
Best Regards,
SC
I've tried it with my 125 with purty good results. Only caveat? You'll definitely need a focal reducer, and the ETX drive does not always produce round stars during 8 second integrations...
Post a Comment
<< Home