Sunday, September 30, 2007

 

Uncle Rod, Astrovideographer

It ain’t like video technology is new to astronomy. Amateurs have been using TV cameras to capture the sky since semi-affordable vidcams and recorders first became available way back in the 70s. It didn’t really take off until the coming of the inexpensive camcorder in the 1990s, however, when planetary observers began using video to capture the Solar System in astounding detail, putting to shame anything that had heretofore been done by film imagers—amateur or professional. But we—we “astrovideographers” as we were beginning to call ourselves—wanted more. We wanted the deep sky.

The experts were quick to say we were cuh-razy. Video, exposing at a nominal 1/30th-second, didn’t have a prayer of capturing even the brightest deep space objects. FUHGEDDABOUTIT!

Huh! We set out to prove those bright boys wrong. Our first approach was to try what the Solar System mavens were doing with great success: stacking hundreds—or thousands—of individual frames via garageware like Astrostack and, before long, the wonderful Registax. That didn’t work quite as well on the deep sky as it did on the planets but, still, it wasn’t long before some talented individuals were producing at least recognizable images of M13 and M42 and sharing them on the Yahoogroup that served as information exchange, Videoastro (still going strong).

There things remained for a little while. Deepsky videoing was somewhat doable, especially with the help of new CCD chips like the Sony ExView series, which were amazingly sensitive, and which were quickly followed by even more light-hungry silicon. The breakthrough didn’t come, though, until a pair of small companies, Adirondack Video Astronomy and Mallincam, began selling what they were calling “deep sky video cameras.” Not only did these use low-lux CCDs, they were able to integrate for far longer than 1/30-second. Today, there are few deep sky objects beyond the reach of the companies’ current top-of-the-line cameras, the Stellacam III and Mallincam Hyper Plus.

So the Mallincams and Stellacams can image the deep sky? So what? What can they do better than a real CCD camera like an SBIG or Starlight Xpress? What they can mainly do better is present a near live view of the deep sky. Set the Stellacam’s integration time to 256 frames, for example, and the image on the monitor is refreshed about every 10 seconds. There’s no computer processing—or computer—required, either. Any TV or monitor capable of accepting composite video inputs can display the outputs of deep sky cameras. Frame, focus, push the “go” button, and DSOs appear on the screen in startling detail.

I often hear folks extolling the value of video for public outreach, and there’s no doubt about its worth in that regard. I’m sure we’ve all had the experience of trying to show a 6-year-old M13:

“Put your eye right up there, sonny. See it?”

“Uhh…”

“It ought to look like a ball of stars. Don’t you see anything?”

“I think I see something.”

In your heart you know this kid and many like him haven’t seen a danged thing. It’s hard for the itty-bitties (and many adults) to see pea-turkey of the deep sky their first time at the eyepiece. Video cures all that. Not only can they see all those wonderful objects as well as anybody else; to kids those galaxies, nebulas, and star clusters frankly are much more appealing on TV than in an eyepiece:

“Mommy, come look. These stars are real; they’re on TV!”

Another argument for deep sky video is that it helps the average light-pollution-plagued amateur to at least see some stuff from home. That it does. Back when our club was using a badly compromised in-town site for monthly star parties, I struggled to see details in even the brightest Messiers. If you held your mouth just right, a 20-inch might show a hint of M64’s black eye. Video? On the worst nights, My C8 is capable of displaying M64’s black eye, M97’s big eyes, and much more that escapes even the biggest of the Bigdobs under the same compromised skies.

But, like they say on them late-night WTBS commercials, “That’s not all!” Video ain’t just for light-polluted backyards. At dark sites it acts as an aperture multiplier. The Stellacams and Mallincams have the effect of, on average, multiplying your scope's size by about 3 times. Not many of us would care to haul around (or be able to afford) a 33-inch scope. Most of us can, however, afford and transport a C11. No, I’ll admit it’s not exactly like viewing through the eyepiece, but the difference is not as great as you might think. Deep sky video has a “look” that’s closer to the visual than to CCD shots. On video, globular clusters, for example, have cores composed of hosts of tiny stars. In the average CCD image these cores are burned-out blobs.

Not that video is the be-all and end-all. While many astrovideographers capture video frames and stack these into decent images like my shot of the Eagle Nebula above (go to my CCD page and scroll down for more), the best video stills are of lower quality than those from cooled integrating cameras or DSLRs. Video is not standing still, however, and, in addition to longer exposures, the most recent Stellacams and Mallincams feature peltier coolers to reduce noise (color is also here now). For the moment, however, "best tool for the job." If you want stills, get an SBIG or a Canon. If you want live views or video to view and admire at home get a Stellacam or Mallncam. Finally, the chips on both the Stellacams and Mallincams are still relatively small in size, so an f/3.3 focal reducer is de rigueur for an f/10 SCT.

Bottom line for Your Old Uncle? Video has allowed me to see more more frequently than I dreamed possible. I want a look at the Horsehead Nebula? That no longer means a trip to the darkest of dark sites with hbeta filters and ST2000s; it’s just a quick jaunt out to my semi-dark club site where I can view Horsey—and show him to my buddies—any time that silly old nag is over the horizon. That’s, in a nutshell, why I’m getting more and more hooked on deep sky video all the time. Yeah, I still like an eyepiece view, but you know what I like even better? Seeing more.

Comments:
Hi "Uncle"....I just have to chuckle at that because we've never met. Regardless, I've become an avid reader of your blog. Myself and my bud are currently constructing a roll-off roof observatory to house two scopes. I've never before given much attention to astro-video applications, but after reading this blog-post I've got to say you've got me jazzed!!!! We're gonna form a new astronomy club with the completion of the observatory with one of our primaary goals of teaching the local kiddies about astronomy. Astro-video sounds like a great way to go! May I take this opportunity to make an invitation to you to visit us in south-central Montana sometime in the future. You can access my 'intro' web page for my e-mail address. Thanks for all you do for the amateur astronomy community.....
 
I'd love to visit y'all way up (out?) there!

;-)

Unk
 
Hi Unk!

Let me second David's invite. Montana boasts "Big Sky Country" and it ain't lyin'. Add to that, we have clear DARK skies the likes of which I only dreamt 'til I got here.

Also, your contribution to me personally, in the pursuit of our avocation, has earned my unconditional and eternal gratitude. You have been and are my beacon. Thank you, so much.

Clear DARK Skies!

Bob
 
PS...I sure would like to hear any comments you may have or will have on Starizona's HyperCam.

CDS!

Bob
 
Do you mean the Starizona Hyper_star_? I know about Mallincam Hyper...
 
I'd sure like to visit Montana? I'm sure y'all must have a great star party...why not have me up as your speaker some time?
 
Yep, must be the Starizona HyperStar thingie. Brings a F/10 SCT down to a F/2, so we're in Schmidt camera country here. 'preciate any input you may have or get.

Outstanding idea! David and I are back-country astrobuffs. Let us see what we can do with your suggestion. Maybe the Billings bunch (city fellers) would be the right venue for such a thing. Be a pleasure to meet and hang with you. Back to you on this...

CDS!
 
I have considered the Hyperstar a time or two...and my still pick one up for the C11. Why haven't I don't so already? I'm stingy. The Hyperstar is purty expensive, and I do pretty well with my Meade 3.3 reducer. Still...like I said, I think about the H-star.
 
Do ya suppose Starizona would be open to sending you one for the C11 for evaluation and an article? Well, do ya? You need no introduction. Seems to me your prominance (notoriety?:-)given your following and experience would be right attractive to them. And, quite selfishly, I'd sure like to know what you thought of it.

I have a C8 which might be just the thing combined with MallinCam/StellaCam/Hyperstar, one of 'em, ought to do what I'd enjoy the most. I'd just like to make that choice based on a clear notion of the relative merits.
 
Rod,if I've given offense, I apologise, that was certainly not my intent. My intent was to encourage you to evaluate the Hyperstar. My wish is entirely sincere.

Bob
 
very good article as usual, you were right for the ethos (just tried the 17mm with my C14, amazing) and my feeling is that you are right for the video too after I saw the pictures from your web site.

I realized recently that I m gonna have problems with an old eye surgery and eyepieces are gonna become a problem for me, I know now that I will endup at some point in my life with video as a very good alternative.
 
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