Sunday, July 28, 2013

 

A Tale of Two Cameras


Unk is a pretty cautious feller, muchachos; I am a big fan of looking before leaping. Maybe because more than a few of the times I’ve jumped in feet first without a good look at what I’ve been jumping into have been disastrous. And that’s exactly how it was in early 2002 when I decided to desert film astrophotography for that new-fangled electronic CCD picture taking.

That I was even thinking about going CCD was ironic, since after about five years of my latest bout of film astrophotography I was finally starting to get somewhere. The Possum Swamp skies, which do not encourage frequent celestial picture taking, and Unk’s fumble-bumble approach to photography meant my astrophotos were not perfect, but danged if they weren't getting closer to it. There was no danger of me becoming a celestial Ansel Adams like Jack Newton, but I was now bringing home a decent shot or two from every single run.

But CCDs were the thing, man. Hell, Sky and Telescope had a whole spinoff magazine devoted to them, CCD Astronomy (for a while). What I thought was the big decision facing the Rodster was which CCD camera to buy. By the turn of the century, there were more than a few choices. The real question actually should have been: “Should I buy a CCD camera before upgrading my old-fashioned manual-pointing SCT?”

didn't realize that was something I should think about, and began shopping for cameras starting with Richard Berry’s homebrew Cookbook Camera. After working on my club’s camera’s circuit boards (you could buy unpopulated PCBs and other camera components through Willman-Bell at the time) for a little while, I knew the Cookbook CCD was not for me. The electronic assembly was easy, but I just didn’t have the time to devote to it. I’d passed the project on to a fellow Possum Swamp Astronomical Society astronomer-ham.

Then there was SBIG, Santa Barbara Instrument Group. In the wake of the tremendous success of their groundbreaking ST-4 they were riding high. I looked long and lovingly at the ST-5, ST-6, and, especially, the ST-7. That camera looked near about perfect for me, but the buzzing fly in the butter was that it was way too expensive. I had 1000 bucks to spend, tops. I coulda got the ST-4, but that seemed more like a guide camera than an imager to me.

In retrospect, the ST-4 would have been great. I could have used it to get my feet wet with digital imaging, and as an autoguider for my film astrophotos. But you know what they say about Monday morning quarterbacking. Truth was, like a lot of imagers, I was ready to move on to the next big thing in 2001.

If I had it to do over I’d get the ST-4. But we don’t get many do-overs in this life, and my desire for the elusive More Better Gooder got the best of me. That came in the form of a camera from a burgeoning UK company, Starlight Xpress. One thing that impressed me was that the images I saw on the web page for the Starlight camera that fit my budget, the MX516, were substantially larger than those of the ST-4 due to the larger chip of the MX516—not that its 500 x 290 pixel chip was large even by the standards of the time. As a guider? That was the most impressive thing of all.

The MX516 could, you see, guide and image at the same time. It did that differently from any other camera I’ve run across. Today’s “self guiding” cameras from SBIG are able to guide and image at the same time because the camera housing incorporates a separate CCD guide chip. It’s kinda like having an off-axis guider with the smaller CCD chip stationed at the edge of the camera frame. Not the MX516. It used an interlaced video-type CCD sensor that devoted alternating “fields” to imaging and guiding. I thought that sounded awful cool.

It was here that I should have stopped and thought things through. The first thing I should have ruminated on was that while the MX516 might be more sensitive than the ISO 800 film I was using, meaning shorter, less painful exposures that might even be done unguided, the resulting pix would be small and in black and white. I was used to color 35mm images that could easily be enlarged to 8x10-inches. Why I thought I’d be happy with postage stamp sized (well, almost) shots I don’t know.

The other thing that should have been a showstopper was something I was aware of and had thought about. Just not enough. With that tiny chip, it would be hard to find objects. Even with the SCT reduced to f/3.3 with the Meade focal reducer I’d ordered, the field would be on the order of 15’ or smaller. I’d planned to order a set of digital setting circles for the C8. I even tried to.

Back in them days, most folks purchased their DSCs from one of two sources, JMI or Lumicon—the old Lumicon, three owners back. I’d heard good things about Lumicon’s Sky Vector system, and since I knew their computers and JMI’s were essentially the same, both based on Tangent guts, I thought the extra objects in the Sky Vector as compared to the library of the comparably priced JMI made the Lumicon DSCs a better value.

The trouble was getting a Sky Vector. The folks at Lumicon were happy to take my credit card number, but weeks passed and I heard nothing from them. I started calling and the results were always along these lines:  “The big cheese, Dr. Acula, ain’t here right now,” “I think it will ship next Thursday,” “Mr. Binky and Mr. Bunny handle those and they are at a star party.” I eventually had enough:  “You-all aren’t ever going to get it together to send me a Sky Vector, are you?” The mousy and halting response amounted to “No, Unk, we are not.”

What I should have done right then and there was pick up the phone and call the reliable and good folk at Jim’s Mobile. In typical Unk fashion, though, my nose was out of joint about the whole DSC idea. Plus I had come up with what I thought was a better and cheaper idea:  “Hell, I’ll use a flip mirror.” I ordered that very thing, an attachment that would allow me to either view the telescope’s images with an eyepiece, or, with the flip of a mirror, send them to the camera, from Meade. In retrospect, failing to get digital setting circles for the Ultima 8 brought my whole big CCD thing down like a house of cards made of wet toilet paper if y’all don’t mind me mixing a couple of metaphors.

I don’t remember who I ordered the MX516 from, but it was probably Astronomics if they carried it, since they were my go-to guys for gear back then. While the camera arrived fairly promptly, it did take a couple of weeks, and its delivery was bumping up against a trip to Florida to visit Miss Dorothy’s relatives. I was in an agony of suspense before our departure, but it worked out that the camera would not arrive until until after our return.

When I finally got to rip into its smallish box, I was both impressed and not impressed by the Starlight. The hardware itself was quite impressive. The camera had the “eyepiece camera” look Starlight maintained in those days; it was not much larger than an oversize 2-inch ocular in those innocent pre-Ethos days. Nicely machined with cooling fins. Sturdy. Solid. Also in the box were a few cables and the Star 2000 box that handled the guide-while-imaging bidness.

What did not impress was “the rest,” the last two items in the box. The instructions amounted to nothing more than a slim sheaf of stapled-together pages. The software? What there was, a simple camera control program, was contained on a single 3.5-inch floppy. Yes, I mean floppy disk. Most PCs sold in 2001 still came with 3.5-inch drives, but disks to put in ‘em were becoming rare, with most software, including CCD camera software, now coming on CDs.

But maybe that was OK, I thought. Simpler might be better when getting started in this CCD folderol and fiddle-dee-dee. The program, minimalist as it was, actually turned out to be purty good. Not only did it allow you to take series of pictures, it even included some processing tools like a utility to stack multiple images. It wasn’t much worse than SBIG’s CCDops, frankly. My first light night disaster had nothing to do with camera and software.

‘Twas a hot summer’s night and I was nervous. Would this thing, on which I’d spent a fair portion of the advance I got for my first book, Choosing and Using a Schmidt Cassegrain Telescope, work? To find out, I lugged the Ultima 8 SCT and my desktop computer (I was still too cheap to glom onto a laptop) into the backyard, got everything cabled up, and did a polar alignment that can best be described as “casual” with the telescope’s polar finder. Screwed the Meade flip mirror onto the C8’s rear port, inserted the camera into the flip mirror along with a 12mm illuminated reticle eyepiece, and got to work.

Everything seemed OK at first; at least the camera and computer appeared to be talking over the cotton-picking parallel printer port (that's right, younguns). Now all I had to do was focus up on an bright star and get the first object of the run, M13, in the camera’s field. Simple, right? Uh-huh.

What to focus on? Eta Hercules was relatively bright and not far from the glob. Hokay, got the star dead in the center of the 9x50 finder crosshairs, flipped the flip mirror down for viewing through the eyepiece, and had a look. Nuttin’ honey. Considerable focusing of the telescope and the flip mirror eyepiece’s helical focuser did begin to reveal a subtle something, a badly out of focus Eta, I presumed. Bottom line? The flip mirror eyepiece would not focus with the Meade f/3.3 reducer on the scope. Period.

What to do? Other than wishing I had some DSCs, all there was to do was soldier bravely on. With heroic effort, I finally got Eta—some bright star, anyhow—in the camera’s frame and focused up. I peeped through the finder and, yes, Eta was dead in the crosshairs. Maybe I’d be OK. Let’s get M13 in the field.

I hunted and I hunted and I hunted and I slewed and I slewed and I slewed. And you know what? I never did get M13 in the camera that night. I settled for an anonymous star field. What did that tell me? Well, that the RS-232 interface was kinda slow, if not pathetically slow, and that the camera did not seem near as sensitive as my buddy Pat’s SBIG. Finally, the pictures the 516 produced were a lot smaller than I thought they would be.

By this time I had reached the dreaded I Have Had Enough stage and started lugging everything back inside, where I proceeded to yell at the kids and snap at the wonderful Miss Dorothy. I am sorry I did, but I was aggravated, disappointed, and dripping with sweat. ‘Twas just one of those nights, campers.

I wasn’t close to ready to give up. As soon as I could, I lugged all the gear out to Pat’s Stargage Observatory, and there things went a hair better. With heroic effort, I got M13 in the field and fired off a few 30-second frames. What I didn’t get working was the autoguiding. I polar aligned as close as I could and followed the instructions in the manual. What happened? Nuttin’ honey. When I got home, I checked all cables and connections, and when that didn’t turn up any problems, I fired off an email to Starlight Xpress. They were very responsive, with head honcho Terry Platt promptly emailing me back. Turned out my Ultima 8 needed a relay box between guider and hand control connector.

I sent the Starlight folks a few more dollars and got the relays, but I was never quite sure the Star 2000 system worked. I was always too occupied with trying to frame and focus my targets to worry about niceties like guiding. I did image a few objects over the next several months: M13, the Cone Nebula, The Ring Nebula, a part of M42, and a couple more. How were they? My CCD pictures got better, slowly, but there was no escaping the facts that they were small, they were black and white, and they were grainy. My film M13s were a million times better.

I could at least have done something about the "grainy" if I’d stacked images. It took me quite a while to wrap my mind around the fact that electronic imagers usually stacked multiple frames into a finished image. I was still approaching CCDing from a film perspective. I also knew I could get color with a filter wheel and tri-color imaging, but I couldn’t imagine adding another layer of complexity when I couldn’t handle what I already had.

I did discover the MX516 could do a right good job on the planets. The images I took of Jupiter—single frames since I didn't know I should stack planetary images either—looked far better than anything I’d done with film. That didn’t make me happy, though. I was in a snit that the deep sky images I was able to obtain were far worse than what I could do with film. I put the MX516 in its case where it stayed for about a year.

If you’ve been in our avocation for a decade and were paying much attention when you first joined our ranks, you know the big story of 2003:  MARS. In 2003, the Angry Red Planet was bigger than it had been in many a long century and bigger than it would be for eons to come. We all wanted to spend the year gazing at the red planet, and many of us, Unk for instance, wanted to take pictures of it. This was a once in a lifetime chance, and I didn't want to screw up.

Film was out. Film exposures of even bright Jupiter take too long. Detail is blurred. Oh, you might get hints of cloud bands, but most of the time Jupe would look like a custard pie. Mars would be worse. It would be bright at the 2003 opposition, but its surface features would be even subtler than Jupiter’s cloud bands. If not film, what? The MX516? Maybe, but I was not overly fond of the camera after that long summer of my discontent. Then I began hearing about a third way, webcams, and, especially, a professionally modified webcam, the SAC 7B.

I was aware of the webcam planetary imaging revolution by this time. Amateurs had found that if they took the little video cameras—that were originally intended for video conferencing and were often used for (ahem) more interesting purposes—and stacked the many frames they produced into a finished image, the level of detail they brought back was amazing. Their small chips with tiny pixels were perfect for producing high-resolution planetary images.

I ordered a cheap Quickcam off’n eBay as a test, and found the combination of it and an easy to use stacking program I’d discovered, Registax, got me the best close-up Moon pictures of my life. Not only was the camera cheap and easy to use, it delivered color images. Only downchecks? It’s 320x240 pictures were even smaller than those produced by the MX5. The Quickcam was also not near sensitive enough to capture deep sky objects. Then I heard about SAC.

When I first heard “SAC” I thought of my old outfit, the Strategic Air Command. “SAC” in this case couldn’t have stood for something more different. The maker of the camera had apparently been a Christian music promoter who’d been involved in a music festival of that genre, the “Sonfest.” He was now, it seemed, dividing his time between managing a motel down in Melbourne, Flordia and producing SAC cameras “Sonfest Astronomical Cameras.”

The model that most interested me was their top of the line, the 7b. It was a converted Phillips or Quickcam webcam that had the ability to do long exposures for the deep sky. It was also equipped with a Peltier cooler and fan to keep the noise down. It was color, and produced images that, while not huge, 640x480, were still bigger than what I got with the pea-picking MX516. All for the comparatively modest price of $499.00.

The problem was that I didn't have a bill with a picture of old Bill McKinley on it in my wallet. The solution? Simple:  the MX516 would have to go on the Astromart. I put it up, asked for a reasonable amount of bucks, just enough to cover the 7b with some left over for a couple of bottles of Rebel Yell, and crossed my fingers. Wasn't long before I got a bite, and the MX5 was off to a new home. Was I sorry to see it go? Not a bit. There were some good things about the camera, but I never made friends with it. Today, I consider the SAC 7b to be my first CCD.

Compared to the MX5, the coming of the SAC7b went smoothly. Took a little while to get it from its garage-style maker, but I’d expected that and the wait was not bad. When it did arrive, just as Mars was beginning to grow, it was an immediate success. The camera was, like the MX5, equipped with a nosepiece that slid into the Meade flip mirror’s camera port. From experimenting with the Quickcam, I knew the flip mirror would be vital for finding planets, and would work just fine without that f/3.3 reducer in the imaging train.

“Once burned” was my middle name when it came to this electronic imaging stuff, so I had the good sense to start out simple with the SAC. I left the long exposure cable and the Peltier cooler for later and aimed the scope at the Moon. While the SAC had come with a CCD full of image acquisition and processing software, I found a program I liked better for camera control, Peter Katreniak’s K3CCD tools. The K3CCD software was designed with astronomy in mind and could control both standard webcams and modified long-exposure ones like the SAC 7b.

Even before I ran my lunar videos through Registax, I knew the SAC was a winner for Solar System imaging. So encouraged was Unk by what he saw on the monitor that he removed the camera from the flip mirror plugged into the NexStar 11, Big Bertha, and added a Barlow lens ahead of it. The picture of Copernicus that resulted after I stacked with Registax and tweaked with Paint Shop Pro was the kind of Moon picture I’d been dreaming of since I was knee high to a grasshopper. One thing that helped one hell of a lot? Having a laptop computer. No more toting a 19-inch CRT into the dagnabbed backyard.

Mars was a revelation. The bigger it got, the better my pictures got. The polar caps were nothing. I began getting the legendary dark areas in astounding detail. Then Olympus Mons and its fellow shield volcanoes swam into view. When Mars attained its max diameter, I was even able to pick out a smudge that might have been a sign of a particularly large crater in the “armpit” of Syrtis Major.

I stared at Mars night after night on my monitor and it stared back at me with its baleful eye, Solis Lacus. Today, imagers using sophisticated planetary cameras, the souped-up descendants of my humble SAC 7, are far exceeding my paltry efforts. Still, as one of my colleagues at Sky and Telescope pointed out recently when I resurrected one of my Mars images for an article in S&T’s Skywatch, my 2003 images showed more detail than had been achieved by the largest professional scopes in the film days.

I didn’t stop at Mars; I headed deeper into the Solar System. What the SAC could do with Jupiter (well, with the aid of the incredible Registax) on a steady night amazed me. Yes, the MX5 had shown some detail, but not this much detail, and it was in color. Saturn was next and not only did the SAC 7 allow me to see disk details that I’d struggled to  see visually, it brought back the Encke Minima, the narrow zone around the Encke Gap at the rings’ edge that I’d only seen visually once or twice in my entire observing career.

“But how about the deep sky, Unk? Ain’t that why you started with the CCD stuff in the first place?” A few users were working wonders with the SAC on the deep sky when it was in its heyday, and while my efforts on bright Messiers were not great, the camera had at least a little potential there, and I was able to accomplish more with it than I had with the MX5. The main strike against it was that that chip was just too tiny to be well-suited for deep space imaging.

That was OK, I learned a lot with the SAC, and that helped me finally get somewhere with electronic imaging with my next camera, the Meade DSI, without much heartburn at all. What I learned with the SAC even stood me in good stead when I moved up to an SBIG ST2000 and a Canon DSLR.

So, whatever happened to SAC? They’ve been gone for years. Ironically, it was not a lack of success, but too much of it that apparently killed them. That, surprisingly, is often what does in small businesses. SAC had a hit with the follow-on to the SAC 7, the SAC 8, which was more a genuine CCD camera than a webcam. So popular was it that Orion, I’m told, contracted to sell the SAC 8 under its brand name. In the course of trying to keep up with demand from Orion and produce the BIG CHIP camera it was promising SAC users, the SAC 10, out the door, the enterprise stalled and crashed.

The SAC7b with its tin can body was in some ways a silly little camera when compared to the beautifully executed MX516. Anybody looking at the two would have had the impression that the Starlight Xpress was better. Maybe it was, but the SAC was the better camera for me. I have no hard feelings about Starlight Xpress; they continue in business and produce excellent CCD cameras. And I guess I learned a considerable amount in the time I owned the MX516—call it the school of hard knocks. Still, the SAC 7b was really my first camera. I loved it, still have it, and even still use it on the planets on occasion. You cannot beat that, muchachos.

Next Time: Uncle Rod's Big Vacation...

Comments:
Great post, Unk. I entered the astronomy gig later in life so I never experienced the nights of film astrophotography. But, I have experienced many of the same frustrations with the ccd's and DSLR's. My images, while okay for my non-astronomy friends, aren't where I want them to be yet....I still keep chugging along.
Hope to meet up in Chief land again sometime soon.
(Tom)
 
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