Sunday, March 02, 2014

 

How do you Video?


I get a lot of questions about video astronomy, muchachos. I’ve done my best to answer them here, in a recent article in Sky and Telescope, and in places like Astronomy Technology Today and Amateur Astronomy Magazine. But they just keep coming, which is testament, I reckon, to how popular the “new” way of observing has become. So, despite us having covered some of this ground before, let’s talk about the nuts and bolts of deep sky video again this a.m. The other reason for this post is that it’s been unrelievedly cloudy in the Swamp and I haven’t been able to actually get out with a scope and see pea-turkey.

I suppose we should talk about the “whys” before the “hows.” There are at least five good reasons for you to consider going video. First and foremost, it allows you to see more. You can see dimmer deep sky objects, way dimmer objects, and you can see more detail in all objects. I’d been puttering around with video since the mid 1990s, but it didn't really take hold with me till I awoke one morning with the conviction that in the observing years left to me I wanted to go deeper, much deeper, and really see what was out there in the Universe.

The obvious way of going deeper would have been by using a big scope visually. Say, something in the 20 – 30-inch aperture range. Alas, Unk, like most of y’all, neither wants to pay for nor tote around such a beast. Luckily, I realized I didn't have to. A deep sky video camera will at least triple the aperture of a telescope. In fact, that really doesn't go far enough. I can see color with my Mallincam. I can pick out tiny 16th magnitude galaxies from a star field by their golden color, and bright nebulae and galaxies are Technicolor riots. I’ve seen hints of color in brighter objects with a 40-inch class scope, but usually only hints. No, your C8 won't best a big-gun for resolving power, but atmospheric seeing doesn't often allow a large aperture scope to take full advantage of its resolving power advantage anyway.

Another reason to like video is that it allows you to do astrophotography with a minimum of fuss. Your pictures will not be as pretty as 8-hour exposures taken with an astronomical CCD camera, but they will look mighty good on the big screen TV in the den, and you will be able to get them without guiding and with a modest mount. Even an alt-azimuth mount will produce surprisingly good results, since a 30-second exposure with an uber-sensitive vidcam will go mighty deep.

Do you do public outreach? If so, video is a natural for that pursuit. Let’s face it, even adults, not just the little folk, have a hard time seeing squat through an eyepiece. They might be able to make out M13, but M51? Rarely. With video, even the tiniest tots can marvel at the sweeping arms of the Whirlpool Galaxy. Video makes dim objects easy for the public to see.

Do your skies suck? Your backyard is badly light polluted and your club site near as bad? Do you rarely get up the gumption to drive an hour or two to good skies for an hour or two of observing? Video cuts through light pollution like a hot knife through butter. Even with video, images will always look better from darker sites, but, nevertheless, a deep sky video camera will show the Horsehead Nebula from the average suburban backyard, something I still find remarkable after nearly ten years of this stuff.

Finally, if you, like Unk, are a certified member of the Old Coot Club, video is such a comfortable way to observe that you may find you outlast the young squirts doing visual observing at the Hoot Owl Star Party (HOSP). I can sit under a tailgating canopy and observe, dry of dew and warm—or at least warmER—on cold nights. "Seated, dry, and warm" equates to “at least three a.m.” for Unk, who’d be lucky to make it till midnight standing at the eyepiece in the cold, damp dark.

Before you can use video to bust through the NGCs to the PGCs and the other crazy-dim sprites that lie beyond, you’ve got to have a video telescope—which is likely the scope you already own. There are a few requirements for a video scope, however.  First, it must be driven. It must track the stars. Given the small size of deep sky video camera chips, ½- inch or even ⅓-inch, trying to track objects by hand would be a frustrating waste of time.

Secondly, you’ll want a telescope with a fast focal ratio and a reasonably short focal length. For the images to be bright and the field wide, a focal ratio of around f/4 and a focal length of about 500 – 1300mm is desirable for most objects. A Schmidt Cassegrain is a good choice for a videographer, since one can easily use focal reducers to speed up the focal ratio and lower the focal length. Most of the time, I use a Meade f/3.3 reducer with the C8 and the C11. Either scope might be equipped with an f/6.3 reducer occasionally if I want to “zoom in” on a smaller object like a planetary nebula.

Can Newtonians be used with video? Heck yeah. Some of the best images I’ve seen have been done with my pals Mike Harvey and Carl Wright’s big-dobs. As above, you will need tracking and you will possibly need to modify your Newt so it will come to focus with a video camera. SCTs focus by moving the primary mirror and have tremendous focus range. A Newtonian that focuses by moving the camera in and out may have to be modified by moving the primary mirror farther up in its cell, moving the focuser and secondary mirror closer to the primary, or, in the case of a truss type scope, having the truss poles shortened.

Finally, a video telescope needs goto. Trying to center objects on a small vidcam chip with a finder scope is not fun campers, not fun at all, even with a wide field telescope. A goto rig also enhances the comfort factor I talked about above. I can send the scope to targets all night long without ever having to leave the cotton-picking EZ Up. Will digital setting circles work? They can, though they are usually not as accurate as a goto mount.

How about telescope mounts? I use both forks and German equatorials for video and both can do well. A GEM is superior for two reasons, however. Most fork mounts are used in alt-azimuth mode in these latter days, so the tracking of an equatorially aligned GEM is superior. Stars are more likely to be round in longer exposures since the scope moves smoothly in one axis to track rather than “stair-stepping” across the sky under computer control like an alt-az mode fork. GEMs are also less prone to cord wrap problems than alt-azimuth forks, and since you will have many cables running to the scope when you are videoing, that is a purty big deal.

Hokay, you’ve got a scope suitable for video use. Camera time. Which to choose? Do you want the (fairly) short answer? At this time, you would be safest buying a Mallincam. They've been around the longest (sorta, see the Stellacam discussion below), and have the widest selection of cams, ranging from the new Micro at about $170 to the Xtreme which comes in at $1500. While most of the Mallincams are available in black and white versions, the big draw for the M-cams has always been color, and that’s probably what you, like me, will want.

Junior Pro
Mallincam has an extensive product line, so which particular Mallincam? In the past, that would have been easy to answer: the Xtreme. It’s the top of the line camera and comes with all the fixins:  Peltier cooler (to keep thermal noise down), full computer control of all camera settings, control without a computer via wired and wireless remotes, and a (relatively) large ½-inch CCD imaging chip. I’ve used my Xtreme for a couple of years now with great success.  What can it do? With my C8, it allowed me to image any Herschel object I turned it on, including small galaxies dimmer than 16th magnitude. And show considerable detail in many Herschels, even the faintest. Brighter DSOs? I got used to seeing spiral arms in NGC galaxies that were mere smudges in the eyepiece.

So the Xtreme is the one to buy? I won’t naysay that. It is a tremendous camera. However, I am also aware not everybody has 1500 dollars lying around to invest in a video camera, particularly if they have never seen video in action and don’t know whether they will really like it or not. Until recently, you could give up some capability for a slightly lower price with the Mallincam VSS or Hyper Plus, or give up a lot of capability for a substantial price break with the (original) Junior. Then, about a year ago, everything changed.

What changed the video scene was the Mallincam Junior Pro. For only 100 dollars more than the entry-level standard Junior, the Pro, at $599.00, gives you one heck of a lot of power. When I tested the camera, I was flat out amazed. The pictures I was getting just didn't look much (if at all) different from what I can achieve with the Xtreme. “OK, Unk, but what’s the catch? How can Rock Mallin sell the Mallincam Junior Pro for less than half the price of the Xtreme?”

There is no denying some corners have been cut compared to the Xtreme. The most serious of which is that there is no cooling. I have not yet used the Junior under summertime conditions, but I do not think that is going to be a huge problem. My old black and white Stellacam was uncooled, and I never had reason to complain about that. To some extent, how you will feel about giving up the Peltier depends on what you are after. If you are trying to make pretty pictures, the lack of cooling may be problematical. There will be more thermal noise visible in the form of “false stars,” warm pixels, than with a cooled camera. If you, like me, however, are more interested in going deep and seeing lots of detail, you likely won’t miss the cooler.

Stellacam III
What else does the Junior Pro lack? Only one thing, really. The Xtreme allows control of all camera settings including long exposure duration with a computer. With the Junior Pro, you can control most settings with a PC, but not all. You must set long exposure integrations using an included wireless hand control. While I prefer doing everything from the computer, once I got friendly with the wireless shutter controller I was OK with it. If you would like more info on the Junior Pro, take a gander at my review in Astronomy Technology Today, and at U.S. Mallincam distributor Jack Huerkamp’s website.

“Wait a minute, Unk. I hear Mr. Mallin has a new camera, the Micro, that costs less than half what the Junior Pro does.” That’s a fact, Jack. The Mallincam Micro is just now hitting the streets, and is already garnering a lot of attention. In no small part due to its amazing price of $169.99, which gets you a ready-to-go camera with a power supply and cables. What makes it so cheap? It’s a more limited camera than the Junior Pro in one major way. The stock Micro uses a ⅓-inch CCD chip. I used to think that was way too small, hell, I thought ½-inch was too small, but I don’t know if I was completely correct about that. A lot of folks seem to like the new ⅓-inch cameras.

“Cameras?” Yep, Mallincam has never been the only game in town when it comes to deep sky video, and there is a new player on the scene, Astro Video Systems, whose current lineup is composed of ⅓-inch cams. What can I tell you about them? The prices are attractive, and their maker seems genuinely committed to improving his products and supporting his customers. I am now beginning to see some decent still frames from these cams—they have not been around long—but I haven’t seen or used one in person yet, so I can’t testify to their image quality. I will say that, like the Micro, the Astro Video Systems cameras are generating a lot of interest and discussion.

And then there is the “Old Blue” of deep sky video cameras, Stellacam. The Stellacam in its original form as a product of John Cordiale’s Adirondack Video Astronomy was there first, even before Mallincam, and it was the Stellacams that tipped me off to the possibilities deep sky video. The evening I saw what a Stellacam II could do under lousy skies, I knew I had to have one. My Stellacam II was primitive by today’s standards—no cooling, black and white, 10-second exposure max—but it served me well for seven years. There is no doubt Xtreme images look much better, and not just because they are in color, but the Stellacam II brought home every single Hickson Galaxy Group I turned it on, no matter how faint.

The Stellacam II had no problem with Hicksons...
Whatever happened to Stellacam? They slowly lost ground to Mallincam. A big problem was the fact that Adirondack never introduced a color camera. Moreover, for quite a while the best a Stellacam could do was a 10-second exposure while Mallincam was pushing exposures ever longer. Another reason the Stellacam faded was that its makers did not interact with the astro-video community. They rarely (hardly ever) posted on the Stellacam Yahoogroup. In contrast, Jack Huerkamp and Rock Mallin were (and still are) on the Mallincam Yahoogroup almost every day. Finally, a few years ago, Adirondack Video Astronomy closed.

That didn't mean the end of the Stellacam. It was bought by "CosmoLogic Systems," who produced the (outboard) cooler for the newest Stellacam, the Stellacam III ($1295).  What’s a Stellacam III? It’s a black and white camera like the Stellacam II, but has had cooling added, and is, like the Mallincams, capable of long exposures.

From what I can tell, the Stellacam III is still available through astro-dealers, though its maker’s webpage is still just the brief 2010 announcement of the CosmoLogic buy-out. Like Adirondack, CosmoLogic does not seem to post in the groups devoted to video astronomy. I always liked my Stellacam II, but the big question regarding the Stellacam III is “why?” Most users will probably be happier with the color Mallincam VSS for a similar price.

“But Uncle Rod, can’t I go CHEAPER?” You can, Skeezix. Quite a few folks are using off the shelf Samsung security cameras, particularly the SCB series, with some success. You can read all about ‘em on the Cloudy Nights video forum. However, my sense is that with the coming of the Mallincam Micro and the Astro-Video Systems DSO-S ($199), there’s not much reason to mess around with “Sammies” anymore.

Alrighty, then, you’ve got a scope and you’ve got a camera. What else you gotta have? You need a way to display the video. Unlike camcorders, deep sky vidcams do not have built in monitors. There are two ways to go:  a video monitor or a computer.

Orion StarShoot DVR
A video monitor is the simplest option. All you need is a monitor or a TV set with an input for composite or Super-VHS video (some Mallincams have Super a VHS output in addition to composite video). Since I am mainly interested in viewing my video on a big screen TV or on a computer at home, I get by with a small screen in the field. I use a nearly ten-year-old portable DVD player with a seven-inch display. It has the advantage that it can be operated on either 120vac or 12vdc. If you choose to go this route, make sure the player you buy has video inputs as well as outputs—not all do.

The other option is viewing video on a computer. If you want to do that, you will need another piece of gear in addition to a laptop. Your computer doesn't know a pea-picking thing about analog video, so you will have to have a device that converts composite or S-VHS video to digital data (often .avi files) that can be displayed by the PC. Mallincam sells these devices, which are usually called “frame grabbers,” but you can get ‘em at the local BestBuy, too.

Monitor or computer? My experience is a video monitor usually produces better images. If you are interested in broadcasting your video over Mr. Mallin’s Night Skies Network, however, you will need to run video to the PC. Just remember that, whichever display you choose, not everybody at a dark site will appreciate your video and will be disturbed by the light from a monitor. Put a red filter over the screen just like you do with a laptop.

How do you save your images for later viewing? If you are running to a computer, the software you use with the frame grabber should allow you to save your video to the hard drive. If you are using a video monitor, it’s more complicated. When I began with the Stellacam II in 2005, I used a cheap VHS recorder. That worked, but the quality was pretty punk. As DVDs sounded the death knell of videotape, I switched to a DVD recorder, which also worked and which I used for years.

A DVD recorder was hardly a perfect solution though. At remote sites without AC power I had to run the home recorder with a battery and inverter, and it would suck down even a big deep cycle marine battery in a right quick hurry. It also had a tendency to corrupt disks when my battery was getting low or when the air was cold and humid. More than once, I found an entire evening’s recordings were lost when it came time to “finalize” the DVD at the end of the night. There had to be a better way.

Still frame from the Orion DVR...
I found that better way a couple of years back with Orion’s StarShoot DVR digital video recorder. This little widget is smaller than a pack of smokes, has a small but legible display, records to an SD card, and features a rechargeable battery that lasts at least a couple of long evenings.  An inexpensive 8gb SD card will usually hold all the video I want to record over a two or three night star party expedition. It gets even better. The video files on the SD card (.avi files) can be loaded into a computer by the simple expedient of removing the SD card from the DVR and plugging it into the PC (if your computer does not have an SD card slot, USB SD card readers are inexpensive). Other comparable DVRs are available, but the Orion is high in quality (though its manual is almost indecipherable), reliable, and supported.

One last requirement before we hook it all together: power for the video camera. Most deep sky cams come with an AC power supply, but I have found that is not a good way to roll. My club site has no AC power, and even when I am at an observing location that does, I find the wall-wart power supplies furnished with cameras tend to produce noisy video. I always operate the camera off a 12vdc jump-start battery. Even the Xtreme, which has a Peltier cooler, draws little current, and a 17ah battery will power it all night long.

OK, time for set up in the field. How you mount the camera on the scope depends on the scope. With a Newtonian, the focal reducer, if you are using one, goes into the focuser and the camera with its 1.25 or 2-inch nosepiece goes into the reducer. Things are a little more dicey with SCTs.

If you are using the Meade f/3.3. reducer like Unk, you screw that onto the scope’s rear port, screw a visual back onto that, and insert the camera into the visual back. The problem comes if you are using a Mallincam and an alt-az fork mount SCT. Due to the long bodies of most Mallincams, they will hit some scopes' drive bases if you go more than about 75 – 80-degrees in altitude.

The fix? It’s not always simple. You can use a star diagonal, but that will put you too far from the Meade reducer for the camera to come to focus. Best bet is a non-Meade reducer. The good old Meade 3.3 seems to no longer be available, anyway. Mallincam (MFR-5) and others make reducers that go on the camera’s nose and can be inserted into the eye end of a diagonal with good results. If your fork mount is in equatorial mode or you are using a German equatorial, you will not have this problem.

Now comes the fun of cabling everything together. Computer control cable goes from the camera to a USB-serial adapter on the PC. Video cable runs from the cam’s video output to a monitor or frame grabber (or a switch or splitter if you are using a recorder). If you are not controlling the camera with a computer, you may have a wired remote for various camera functions and a wireless shutter controller for a Mallincam’s long exposure setup (you’ll plug a wireless receiver module into the camera). Obviously, when you add the telescope’s power cord, computer control cable, dew heater power cable, and motofocus cable, you have a mess of cables, and you may want to look into various strategies for bundling them together to prevent the scope from being wrapped up like a dadgum mummy.

Next, you fire up all that stuff, set the camera exposure and other things, and have at it. How do you set up the camera? How do you get good images on your display or into your recorder? That is somewhat complicated, though after a few video runs it will become second nature to you. It is also a story best left for another Sunday. It seems, muchachos, that despite what Professor Einstein says we are slap out of time and space.

Next Time:  Betsy! Betsy! Betsy!

Comments:
Thanks for the link to your ATT review.

When did Rock Mallin buy the NSN?
 
Is it possible to stack and further process these files?
 
HI Dan:

It certainly is...people stack them with Registax and then process.
 
Thank you for the introduction to video observation. I live in the middle of Manhattan, so this may be a good option for me and my C5!
 
Thanks for this informative intro... I'm getting ready to pull the trigger, but wonder where the ZWO ASI120 fits into the mix -- do you lose anything with the USB connection to the computer vice the multi-cabling from the Mallincam and Astro-video systems?
 
Thanks for the informative intro... I'm getting ready to pull the trigger, but wonder where the ZWO ASI120 fits into the mix given its USB computer connectivity? Is anything lost when using USB vice the Mallincam and Astro-video systems?
 
HI Don:

Depends. The ASI is a remarkable camera, but the Mallincam and Astro Video cameras are superior for the deep sky. The ASI is certainly better on the planets.
 
Great post as usual. Any chance of you "borrowing" a micro-EX for a review? That bad boy could be a game-changer. I would buy it just to get started and then move up to a Jr Pro and use the EX for a guider....

Jack
 
Ya great post Unk. You definetly piqued my interest in these cams also.
Thanks a mill and clear skies
Patrick
 
Mallincam JR PRO "PC" version has (so I heard) complete exposure control up to 99 mins with your laptop computer controlling it by remote control over a cable. No Mallincam wireless control handset needed. Cheers, Alistair G.
 
Many broken promises from AVS on the DSO-1 I ordered. I asked specifically if he could deliver by April 1st(I had neck surgery the 16th and wanted it in before because I cannot work with my arms up for 6 weeks) and was told yes he should be able to get it here around the 1st.

It is the 2oth, camera finally arrived, video connector is bent sideways and looked used, it has corrosion on the barrel. It took a complaint to paypal to even get him to ship, he should have just refunded my money like I asked instead of printing a label then scrambling a week to find a camera to ship(yes there was a week delay between label printing and shipping). Now I have to repack it in a better box, deal with shipping, when all I want to do is recover from a multi level neck fusion.

Run away fast AND DO NOT BUY FROM Astro Video!
 
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