There are many different names used to describe the activity of using an analog video camera or a digital USB camera to enhance the view through the lens or reflected from the mirror of a telescope. Electronic Assisted Astronomy or, EAA, is probably the most commonly used name and is the name used for a popular Cloudy Nights forum. But it is in my opinion a bit too general since the "Electronic" part of the name could simply mean a tracking mount, Night Vision equipment (as it does for the CN forum), some form of computer control, a WiFi connection, etc. The term "Near Real Time Viewing" is also commonly used since the effect is to see great detail in galaxies, nebulae, etc. in a matter of a few or tens of seconds. Video astronomy was the name used in the early days since, until recently, the most commonly used cameras by far were analog video cameras like the Mallincam, Stellcam and Samsung to name a few. But the name I like best is Camera Assisted Viewing since it goes to the heart of the activity which is to use a camera to collect light during short exposures of a few seconds or tens of seconds thereby greatly enhancing the detail seen compared to looking through the same telescope but with an eyepiece. The camera could be a video camera like those mentioned above, a digital camera like those from ASI, QHY or Starlight Xpress or even a DSLR. Often software like Sharpcap will be combined with the camera to provide on-the-fly stacking and processing to further improve what can be seen in seconds to minutes.
So, regardless of what we call this, I have wondered where and how did it all begin?
In the Beginning: Camcorders
The image of Gil Miles using a CCTV in 1961 to view the moon live on a TV screen signals the possibilities which were to come to fruition in the coming decades. Video astronomy would not only allow amateur astronomers to observe much more than they could with an eyepiece, they could do this in more comfort and they could simultaneously share the view with others. This particular photo is amusing when one notices the formal attire Gil is wearing while comfortably seated in his armchair. We have come a long way in the last 58 years in more ways than one.
It was not until Sony introduced the first consumer camcorder in 1983, the Betacam, that video astronomy finally was within reach of the average amateur astronomer. With the aid of a camcorder, armature astronomers were able to enhance their views of the moon and the planets and capture video to be viewed later or processed to make pretty images. However, because of the size of these early camcorders (they generally also housed a VHS or Beta tape recorder) they needed to be mounted onto a tripod or hand held at the eyepiece of a telescope for afocal imaging. Over time camcorders became smaller and lighter and easier to use with a telescope and some had detachable lenses so that the camera could be mounted at prime focus of the telescope. But camcorders were still limited to bright objects like the planets, the moon, double stars and lunar occultations because of their low light sensitivity (1-5 lux), short exposures (1/60th sec.) and lack of manual control of the exposure and gain settings. In addition, camcorders had auto focusing, which made them even more of a challenge to adapt to astronomy. Indeed, Dennis di Cicco reported in his review of the Canon L1 camcorder in Sky &Telescope April 1992 that he could only record a trace of the bright core of the Orion Nebula through a 200mm/f1.8 lens. Nonetheless, intrepid amateurs showed the advantages of adapting camcorders for astronomy as the age of Camera Assisted Viewing began.
In 1994 the first commercial webcam, the QuickCam, was introduced for $99. In contrast to camcorders, webcams were not only inexpensive, they were also much smaller and lighter and more easily adapted to astronomy. And, they came with a USB cable and software for easy connection to and control by a computer. The QuickCam and the Philips ToUcam were two of the more popular early webcams using Sony's 1/4" ICX098BQ CCD detector with 350K total 5.6um square pixels. In contrast to the camcorder, webcams had a maximum exposure of 200 msec which was nearly an order of magnitude longer than that of a camcorder. While offering the amateur astronomer improvements over the camcorder, the webcams did have their limitations. Since they were designed for terrestrial use, they required mechanical modification to enable attachment to a telescope. This involved surgery to remove its lens and add a c-mount adapter. And the small size of the detectors used in webcams greatly limited their field of view, making it sometimes difficult to find and center the object of interest. Ultimately, with sub-second exposures (0.2 sec.), small chips (1/4"), small pixels (5.6 microns), poor sensitivity (initial Lux values of 10 to 20), webcams were limited to bright celestial objects like the moon and the planets. Despite this, webcams quickly made their mark as premier planetary imagers. By taking advantage of their 60 to 90 fps image capture rates amateurs could collect thousands of images of a planet in a few minutes which they would post process later. Using free software like Registax to automatically select and align the better images produced during brief moments of exceptional seeing, amateurs were able to produce images rivaling those of professional astronomers with much larger and better telescopes only a decade earlier. As this approach gained traction, the Quickcam and Unconventional Imaging Astronomy Group (QCUIAG) was formed in 1998 as an online forum where new methods, cameras, modifications and images could be shared among like minded video astronomers.
It did not take long for some enthusiasts to push the envelope and figure out how to modify these webcams to achieve longer exposures and begin using them to successfully view and image some of the brighter Deep Sky Objects (DSOs) like star clusters, galaxies and bright nebulae. In 1999 Dave Allmon found that by clipping a single wire in the Connectrix webcam he was able to take long exposures which he demonstrated with images of 5 sec to 180 sec duration of the Andromeda galaxy. Unfortunately this capability was a quirk of the Connectrix camera and could not be applied to other Webcams. Then in the summer of 2001 Steve Chambers is credited with pioneering a series of modifications to a wide variety of webcams allowing long exposures, replacement of the standard CCD with larger and more sensitive CCDs and disabling of the amplifier to minimize noise. While amateur astronomy is flush with do-it-yourselfers, not everyone has the skills or desire to make their own modifications. Enter the commercially modified webcams from the likes of Atik (ATK-1C, ATK-2C), SAC (SAC7, SAC7b), Celestron (NexImage), Meade (Lunar and Planetary Imager and Deep Sky Imager), and Orion (Starshoot Solar System and Deep Space). The ATK-1C and NexImage were commercial modifications of the ToUCam. All of the commercially modified webcams were designed with housings to fit into standard 1 1/4" eyepiece holders, many had passive cooling designs and some even had fans to better reduce the appearance of warm pixels. They also came with larger chips for larger fields of view and larger pixels for improved light sensitivity. And all provided longer exposures than unmodified webcams pushing practical exposures into the range of minutes. This finally made it possible to create images of DSOs by collecting hundreds of exposures of a few tens of seconds which could later be stacked and processed with software like Registax. See for instance, Stephen Chambers and Stephen J. Wainright, Sky &Telescope Jan. 2004. At this point it was possible to do Camera Assisted Viewing of brighter DSOs with a webcam, but this limited capability was already being made moot by the availability of integrating video cameras from SBIG, Adirondack and Mallincam leaving webcams as the mainstay for lucky imaging of the solar system rather than the key to Camera Assisted Viewing of DSOs. A complete review of Webcams and their applications to astronomy can be found in Robert Reeves 2006 book, "Introduction to Webcam Astrophotography".
As the search for ever improving capability evolved in the 90s, amateur video astronomers eventually began experimenting with low-light video surveillance cameras. While larger than webcams these cameras came with higher sensitivity, detachable lenses and c-mounts allowing them to fit nicely into 1 1/4" eyepiece holders. They were typically used with a frame grabber and a VHS recorder to capture thousands of frames which could later be stacked in software to produce excellent solar system images, some say better than what could be obtained with long exposure film cameras.
In 1994 two amateur astronomers in upstate New York, John Cordiales and Jim Barot, saw the value in these video surveillance cameras and launched their own company, Adirondak Video Astronomy. One of their first products was the Astrovid 2000 in 1996 which sold for $595. This camera used a Sony 1/2" B&W CCD, ICX038DLA, and had an exposure range of 1/60 sec to 1/10,000 sec making it well suited to solar, lunar, planetary and occulations but not DSOs. A big advantage of the Astrovid 2000 was the fact that it provided for manual adjustment of the shutter, gain, gamma and contrast through a wired hand control providing the needed control over the image settings and also making it possible to change camera settings without disturbing the telescope. David Moore published a detailed review of the Astrovid 2000 in Sky & Telescope Aug. 1999. While still not ready for DSO viewing, John and Jim would soon play a pivotal role in reshaping the nature of video astronomy.
Then in 1998 a Texas company, Supercircuits, introduced two very inexpensive video surveillance cameras, the PC-23C and PC-33C, a B&W and color model, respectively. Because these cameras could be purchased for only $80, they quickly became very popular in the video astronomy community. These re-badged Topica TP-505D/3 cameras from Taiwan used 1/3" Sony CCDs and had a maximum exposure of only 1/30 sec. Unlike the Astrovid 2000, the Supercircuits cameras had auto exposure and auto gain mading the cameras challenging to obtain the needed exposure for small, high contrast objects like the planets. In his Skywatch March-April 1999 review of the PC-23C, Rod Mollise noted the excellent views he achieved of Saturn and Mars, including a clearly defined and razor sharp view of the Cassini Division. But, he noted, " For 'real' deep sky work you do need an integrating CCD camera..." Even though these inexpensive Supercircuits cameras were not capable of viewing DSOs, they were quite capable at capturing images of the solar system and the B&W version was a favorite tool for asteroid occultations.
Similar to Topica, another Taiwanese company, Mintron, and a Japanese company, Watec, began developing and selling video surveillance cameras in the 90s. Cameras like the Watec 902H ($500) with its 1/2" Sony ICX249ALL CCD also found their way into the amateur astronomy community even though the manufacturers were not initially aware of this application for their products. But with exposures still limited to 1/60sec (NTSC) and 1/50sec (PAL) these cameras were also not useful for viewing DSOs. Nonetheless, both Mintron and Watec cameras would be key to shaping the nature of Camera Assisted Viewing over the next decade, if primarily through several innovative amateur astronomers who saw the value of this new technology.
While the 90s brought a new technology, video surveillance cameras, to the forefront of amateur astronomy, maximum exposures of 1/30 sec limited the cameras, like the webcams, to the solar system, asteroid occultations, lunar meteor impacts, double stars and bright open clusters. To take advantage of this new branch of astronomy, a Yahoo Video Astro Group was formed by Jim Ferreira in the spring 1999 providing an on line forum for discussion of video cameras and equipment for lunar, solar and planetary astrophotography, and eventually DSOs. That forum continues to this day.
Integrating Astro Video Cameras
In the Beginning: The SBIG STV
The first video camera designed and marketed for real time viewing of DSOs is probably the SBIG STV. This dual purpose guider and video camera was introduced in 1999 with with the capability to perform exposures of 1 msec to 10 min. In their 2000 book, "Video Astronomy", Steve Massey, Thomas Dobbins and Eric Douglass called the arrival of the STV a "first glimpse into the exciting future of video astronomy." The longer exposures afforded by the STV suddenly made it possible to view images of DSOs in real time without the need to capture thousands of individual frames for stacking and processing later. An exciting new age in amateur astronomy had arrived.
The key to longer exposures is the ability of the camera to integrate the light captured by the CCD over many 1/60 sec (NTSC or 1/50 sec PAL) exposures effectively creating a single longer exposure. This long exposure is stored in the camera's buffer and continuously output to the monitor at standard video rates, 30 frames/sec NTSC or 25 frames/sec PAL. When a new long exposure is ready it is transferred to the buffer and output in the video feed for viewing until the next long exposure replaces it. Thus, one can view an image continuously on the monitor while the camera takes the next long exposure.
The STV is an all-in-one system with a CCD camera attached by an electrical umbilical cord to a large control box just under 12" x 10" x 3". The camera uses a sensitive B&W 1/3" CCD sensor from Texas Instruments, TC-237. The STV gives the user manual control of exposure, gain, brightness and contrast providing the user with complete control over the camera, unlike camcorders and security cameras like the Supercircuits PC-23C and similar cameras of the day. With the STV it was now possible to view all of the Messier objects with exposures in the range of a few seconds to minutes. In many ways the STV was way ahead of its time considering that it also came with a Thermo Electric cooler, automatic dark frame subtraction to minimize noise, complete control of the camera's settings, image display and image capture with or without a computer and a feature called "Track and Accumulate". The "Track and Accumulate" feature allowed the camera to internally align and stack up to 10 frames in real time to dramatically improve SNR reducing noise and improving feature detail. The STV also had the ability to store images in the on-board internal memory for later display or download to an external computer. Optional accessories included a 5" B&W LCD monitor, color filter wheel and a focal reducer with an extension tube capable of reducing an f/10 system to ~f/6 and f/3.75. The focal reducer could also turn the camera into a wide field finder "eFinder" with a FOV of 2.7 degrees. Alan Dyer gave a thorough review of the SBIG STV in the Jan. 2001 Sky &Telescope.
However, at a price of $1995 for the base unit and $2395 for the Deluxe with the LCD display, this camera was out of reach of many amateurs who continued to look for a cheaper alternative. The STV was discontinued in 2006 due to the lack of key component availability, but used systems can occasionally be found for re-sale on Cloudy Nights.
A Couple of Guys in Upstate N.Y.: The Stellacam
In the meantime, a number of forward looking amateur astronomers were working on adapting existing security video cameras from companies like Mintron and Watec for astronomical use. As mentioned above, Adirondak Video Astronomy was one those and although their Astrovid 2000 was not suitable for real time viewing of DSOs, things changed in the fall of 2001 when they introduced the Stellacam for $595. While this camera had the same CCD as the Astrovid 2000 the key difference was the capability to integrate up to 128 x 1/60 sec image frames for a maximum exposure of 2.1 sec. This extended exposure capability, while not as long as that of the STV, was sufficient to make it possible to view many DSOs in real time that were not possible previously with cameras like the Astrovid 2000, Supercircuits PCs, modified webcams and camcorders. The Stellacam was in reality a re-badged Mintron MTV 12V1 with the IR filter removed to increase sensitivity at the important Halpha wavelength. It also had a different rear panel than the stock MTV 12V1. Instead of the 5 buttons to navigate the camera on screen menu, the BNC video and S-Video connectors, a power input port and a green LED, the Stellacam had a single multi-pin connector for the cable to connect to a wired hand control. Unlike the more sophisticated hand control for the Astrovid 2000, the Stellacam's hand control was a small metal box with five buttons and a resistor network inside so the user could to emulate the camera menu buttons on the back of the camera body. This box also had an input for camera power and a BNC connector for the video output from the camera. This enabled a single wire from the camera to the observer several feet away. While the STV heralded a new world of possibilities, the Stellcam, even with its limited exposure, opened up that new world to many more astronomers at 1/3 the cost of the STV.
The Stellacam was followed by the Stellacam EX in 2002 ($695) and the Stellacam II ($795) in 2003 further improving the depth and detail of DSOs which could be viewed in real time. The EX was another re-badged Mintron security camera, the MTV12V1Ex. It was still limited to 2.1sec exposure but with the more sensitive 1/2" Sony ICX248 CCD it could provide much more detail than the Ex. It came with the same hand control as the non-Ex camera. In his review of astronomical video cameras available at the time in Sky & Telescope Feb 2003, Johnny Horne noted that both the Stellacam and Stellacam EX were "sensitive enough to put the Triffid Nebula directly on a TV screen in real time."
With the Stellacam II, Adirondak switched manufacturers from Mintron to Watec, re-badging the Watec 120N which had the even more sensitive Sony 1/2" ICX418 CCD. But the biggest improvement with this camera was the capability to increase internal stacking to 256 frames for a maximum exposure of 8.5 and 10.2sec, respectively, for the NTSC and PAL versions of the camera. The Stellacam II was supplied with a much more sophisticated wired hand control than either the Astrovid or the Stellacam Ex. Most likely the new hand control was manufactured by Watec itself, since one could purchase the exact same camera and remote directly from Watec. This remote had rotary knobs for adjustment of the exposure integration (1X , 2X, 4X, ... 256X) and Gain along with a sliding switch to change the Gamma. An optional wireless hand control was available instead of the wired hand control eliminating one extra wire from the camera to the observer.
The last of the Stellcam series, the Stellacam III ($1295) based on the Watec 120N+, was released in 2006. It had the same CCD as the Stellacam II but now had an unlimited maximum exposure which made the Stellcam III the ultimate an astronomer could ask for. Now, the ability to view DSOs was more limited by the mount polar alignment, tracking capability and light pollution rather than the upper limit of the camera exposure. The Stellacam III had the same wired and wireless hand control options as the Stellcam II. But it also introduced Thermo electric cooling (TEC) of the sensor with the addition of a Peltier cooler like the STV to help reduce thermal noise. In his 2005 book, "Visual Astronomy Under Dark Skies", Antony Cooke called the Stellacam line of cameras "true astronomical video pioneers."
Around 2010, the Stellacam line of cameras was taken over by John Lee's CosmoLogic Systems. Cosmologic had provided the Peltier cooling for the Stellacam III and the wireless remote for Adirondak's camera. When Cordiales decided to leave the business, Lee stepped in, at least for a short time. It seems that the change in ownership, the fact that Stellacam never introduced a color camera and stiff competition from another innovative amateur astronomer ultimately led to the disappearance in the Stellacam line earlier this decade. Used Stellacams can still be found in the Cloudy Nights or Astromart classifieds, but have long since been supplanted by much more capable and even less expensive video cameras.
A Guy Even Further North Joins the Fun: The Mallincam
In the meantime, up in Canada a fellow named Rock Mallin began tinkering with video cameras for astronomy in earnest in 1994 and introduced his 1st commercial camera, the Mallincam I (MC I) in 1999. This first camera also used a B&W 1/3" CCD and had a maximum 1/2 sec. exposure which limited its use to the solar system and lunar occultations. It was not until late 2002 or early 2003 that the Mallincam II was introduced with the ability for exposures of 2.1 sec, long enough to display many DSOs in real time. It used the same Sony CCD as the Stellacam and the Mintron 12V1 and appears to be a modified version of the Mintron. It is likely the MC II that Terence Dickenson reviewed in Sky News Nov/Dec 2003 remarking that " On the deep sky, the Mallincam really shines." The MC I and MC II appear not to have widespread distribution and may have only been used by a handful of amateurs in Canada. But this would change dramatically as Rock released a succession of analog video cameras with key improvements over the next decade. His MC II Color camera introduced in late 2003 or early 2004 was the first commercially available long exposure astronomy video camera with color capability and a major game changer for deep sky camera assisted viewing. The MC Hyper in 2004-2005 extended exposures up to 12 sec with its "hyper" circuitry. The Hyper Plus introduced in 2005 and reviewed by Gary Kronk in Astronomy, July 2010, extended the maximum exposure to 56 sec and appears to be the first Mallincam camera with Peltier cooling. It is likely that with the Hyper and Hyper Plus cameras, the Mallincam line really took off. The VSS and VSS+ in 2007-2008 pushed the maximum exposure to just under 2 min. and also were equipped with a Peltier cooler. With the Xtreme in 2009 the maximum exposure was now 100 min., certainly beyond any real time viewing threshold. The B&W versions of the Hyper Plus, VSS, VSS+ and Xtreme all used the Sony ICX428, while the color versions used the ICX418, all 1/2" format. The Xterminator introduced in 2014 with the extremely sensitive Sony ICX828 CCD was the last of the new analog cameras from Mallincam. Rocks cameras ranged in price from $249 for the Micro kit to $600 for the MC Jr Pro model up to $1750 for the Xterminator. The Mallincams have been some of the most popular, if not the most popular cameras in the post Stellacam era. Many of these cameras are still available today along with a line of digital CMOS cameras for both real time viewing and astrophotography.
From Down Under: The GSTAR
While Stellacam and Mallincam were well established in the video astronomy community in North America, down under an Australian company launched by Steve Massey in 2002, MyAstroShop, began marketing its GSTAR line of astronomy video cameras. Steve eventually released 3 analog video cameras over the years, all re-badged Mintron cameras. The GSTAR EX was first with the 1/2" Sony B&W ICX429AL CCD and a 2.56 sec maximum exposure. This was followed by the GSTAR EX Color, most likely a re-badged Mintron72S85HP-EX with the 1/2" Sony ICX249AK and 5.12 sec maximum exposure. The last video camera in the GSTAR series was the GSTAR EX2 ($579) with the 1/2" Sony B&W ICX429 CCD also with a maximum exposure of 5.12 sec. It appears that all of the GSTAR analog video cameras are now discontinued but have been replaced with CMOS digitial cameras as the hobby has moved in that direction. Steve's cameras had their IR filters removed like both the Stellacams and Mallincams. Unlike the Stellacams and Mallincams at that time, the GSTAR cameras could be controlled by a computer with the free GSTAR-COM software. An optional 10 meter RS232 to DB9 cable was needed to connect the pc to the camera through the camera's Aux port. In addition to the camera shop, Steve has advanced the hobby by authoring several books, including two books on video astronomy in 2000 and 2009.
The Stock Security Camera: Mintron, Watec and Samsung
While it does not appear that Mintron actively marketed their cameras to the astronomy community, that did not stop astronomers from seeking out their latest cameras for such use. This included the MTV12V1 and 12V1-EX which were used in the Stellacam, Mallincam and GSTAR line of cameras to name a few. Other Mintron security cameras like the 12V6HC-EX color camera also found their way to the back of telescopes through word of mouth on one astronomy forum or another. In Astronomy Now Dec 2007, Ade Ashford reported that he was able to see the dust lanes in the spiral arms of M31 with a Mintron 12V1-EX attached to his 105mm f/4.2 AstroScan.
At some point, Watec began to realize that their cameras were being used for astronomy and began to advertise them as such. Their 120N and 120N+ with wired remotes were sold direct to astronomers as well as re-badged by Adirondak and sold as Stellacams. Like the Mintrons, amateurs sought out any promising camera from the likes of Watec over the years.
In 2008 Samsung introduced its SDC425 video security camera with a 1/3" color Sony CCD and the capability for 4.2 sec exposure integration for the comparatively low price of $175. In 2009 the Samsung SDC435 (later renamed the SCB200) was released with a 1/3" Sony ICX638 color CCD and an exposure of 8.5 sec for just $99. This became a very popular camera given its price and reasonable capability for deep sky viewing. The SCB4000 with the 1/2" Sony ICX428 CCD was released in 2009 for $347 and it also had a maximum exposure of 8.5 sec. These cameras have a plastic IR filter placed in front of the CCD which is easily removed since it is held in place with two small screws. The Samsung's were never marketed for astronomy and apparently never re-badged and resold to the hobby, but could be purchased direct from security video camera suppliers. They were much larger than the Mintron and Watec cameras and are still popular today, although the above versions are no longer in production.
A Late Arrival: The LNTech300
In 2013, word spread of a new, small form factor security video camera manufactured in Hong Kong and available on-line from a number of Asian re-sellers. Like the Samsung, this camera was not directly marketed to the astronomy community, but awareness within the ranks soon made it a very popular camera. That and the fact that it could be purchased for a mere $69 yet had the capability for exposures of 20.5sec PAL and 17.1sec NTSC. Not only that, but this camera had the capability to internally stack up to 5 successive images on the fly, a process called 3D-DNR, which greatly helped increase SNR and smoothed out the noise and enhanced the detail. The LNtech300 used the 1/3" Sony ICX810 and 811 CCD for NTSC and PAL, respectively. Since this camera was not sold directly as an astronomy camera, one had to either ask the re-seller to remove the IR filter glued on top of the CCD or remove it themselves, which many did. The main limitation of this camera was the fact that it used a 1/3" CCD at a time when most amateur astronomers were already used to the 1/2" format and were looking to the possibility of even larger sensors in the future. The main advantage was its low cost making it appealing to anyone just entering the hobby.
Mallincam came out with a rebranded version of the LNtech300 called the Micro Ex in late 2013. This camera was identical to the LNtech300 except in two important ways. First, the IR filter was already removed from the CCD. Second, the Micro had some internal wires spliced so that the Auto Iris connector could be used with the proper cable to control the camera menu by a computer and free SW which emulated the buttons on the back of the camera. This was a very nice feature for those who wanted to use the camera with a computer. A DIYer could easily make the same modification to the LNtech300 which many did. In fact, one can find threads on the Cloudy Nights forum for this and another modification to provide WiFi control of the camera as well.
End of the Line: The Revolution Imager
The LNtech300 was re-badged and sold along with several useful accessories by Orange County Telescopes starting in Sept. of 2015 as the Revolution Imager. It used the PAL version of the CCD, the ICX811, which provided a maximum exposure of 20.5sec. While most camera suppliers included a C-mount adapter, a power cable or power transformer and maybe a video cable with their cameras, the Revolution Imager kit was unique in the completeness of the included accessories. For $299 you received the camera with the IR filter already removed, a C-mount adapter, power and video cables, plus an external 1.25" IR filter, a 0.5X focal reducer, a 7" LCD display, and a rechargeable battery all neatly arranged in a padded soft carrying case. The user need only supply the telescope and a clear night sky. The Revolution Imager was reviewed by Rod Mollise in his Dec 13 2015 Astro Blog where he concluded that the Revolution Imager was not only inexpensive but a "very capable camera." Unfortunately the LNtech 300 supply from the Asian re-sellers was exhausted by late 2015 or early 2016 and with it the last of the Revolution Imager cameras.
Fortunately, Mike at OCT was able to source a new analog video camera by May of 2016 which he called the Revolution Imager 2. This camera comes in a square rather than a rectangular case format but with the same ICX811 sensor. However, the firmware for this camera differed from the RI I such that the maximum integration was x256 and not x1024 like the RI I. Thus the longest exposure was 5.1sec. However, the 3D-DNR allowed averaging of 6 successive frames instead of 5 which gives a 30.6 sec total average signal. The RI 2 is still available today from OCT and a number of astronomy retailers.
And Then There Were: Orion, PD, Polaris, ITE, SC2000
While the cameras mentioned so far probably account for the vast majority of video cameras used for deep sky viewing, I would be remiss not to mention some others. One of these, Orion Telescopes, marketed their offerings as the StarShoot Deep Space Video Camera I and II. Both cameras were simply re-badged Mintron 72S85HN-Ex-R color cameras with a 1/2" Sony ICX248AKL (NTSC) or 249AKL (PAL) CCD and an integration of 256X. The only difference of the DSVC II appears to be an added serial interface for computer control. Polaris USA marketed several different Mintron cameras without modification including their most popular model the Matrix (Mintron MTV12V1) and their color model the Polaris DX-8263SL, a re-badged Mintron MTV63V1. ITE appears to have sold three different cameras, the Deep Sky Pro, a re-badged the MIntron 12V1, the Deep Sky Pro EX, probably a re-badged Mintron 12V1Ex, and a color camera called the Color Eye Pro. In the U.K. Phil Dyer is still a major supplier of video cameras. These include the B&W Mintron MTV2285HC-Ex with a 5 sec exposure which he calls the PD2285C-Ex. Phil also has a color camera which is a modified Huviron (Korea) security camera with an ICX638 (NTSC) or ICX639 (PAL) Sony CCD with up to 20sec maximum exposure. Several of these cameras are discussed in Adrian Ashford's Dec 2003 Sky & Telescope article on integrating video cameras.
In early 2015 yet another deep sky video camera option came to light with a posting on the Cloudy Nights EAA forum by "photo444". He documented a DIY project to build a camera from the pc board containing the CCD and electronics which he purchased from SecurityCamera2000 for just $23. A wired remote was included which was easily attached to the appropriate points on the camera board with push on connectors. Originally, these cameras came with the typical IR filter which removes some of the useful IR light from deep sky objects. However, it was not difficult to remove by applying heat to the glass filter with a soldering iron. Fortunately, the DIY project became a lot easier when it became clear that one could request the board camera without the IR filter directly from the supplier. Then all that was required was to build a simple enclosure and attach the board camera, feed through the wire harness for the remote and connect a C-mount adapter to the face of the box. The original idea came from another poster on Cloudy Nights, "David B in NM", who had suggested it to "photo444". This board camera compared favorably in performance with the LNtech300. It used the 1/3" Sony ICX638 and ICX639 CCD and had a maximum exposure of 1024X. This camera set off a wave of similar extremely inexpensive but capable DIY board cameras. More information and images cane be found on the Cloudy Nights forum by searching "SC2000" on the EAA forum and by reading the blog on this web site do-it-yourself-board-camera-for-35.html
Its Not All Hardware: Software Plays Its Part
Indeed, while the focus to this point has been on the development of the ever improving hardware that collects the photons necessary to view deep space wonders, software may be the unsung hero that has had its own ongoing role in the advancement of video astronomy. Software's contributions can be divided into two important categories: 1) camera control; 2) image capture.
A major challenge for newcomers when trying to operate one of the video cameras is the fact that the camera settings are designed for video surveillance applications, not for astronomy. Hence, the menus can look like Greek to the uninitiated with many of the functions completely irrelevant to astronomy applications. On top of that, important camera settings can be buried several layers deep within the menu. A more in depth discussion of this challenge can be found here making-sense-of-video-camera-osd-menus.html . Fortunately, some very helpful individuals have come to the rescue and created free software which put all of the relevant camera settings in an easy to view, understand and modify format. Two such examples are the GSTAR-COM software developed for the GSTAR and Stephan Lelonde's Mallincam Control software developed for the Mallincams. Both are free and both require that the camera be connected to the pc with the appropriate cable which can be obtained from the camera supplier. These simple to navigate and effectively organized menus leave out the camera functions one would never use for astronomy and make it much easier to navigate through the control settings needed for astronomical viewing. While these programs made controlling the camera much easier they did not provide for image capture and processing.
As video cameras became more popular and amateur astronomers craved to go deeper, minimize noise, remove hot/warm pixels and save images more sophisticated software began to appear. In 2010 Robin Glover released a program called Sharpcap which was originally developed to simplify camera control and image capture for Webcams in place of existing programs like AMCAP. In 2012 Sharpcap was revised to work with additional cameras which eventually grew to include Basler, ZWO, Starlight Xpress, QHY, Celestron, Point Grey, almost all Webcams, cameras with an ASCOM driver and most frame grabbers. Sharpcap provides a simple layout with a live image along with camera controls all in a single screen view. Over the years Robin has added new features to the camera making it extremely useful for real time image viewing, processing and capture. These include on the fly dark frame subtraction, flat frame correction, image stacking, histogram adjustments, polar alignment, plate solving, focusing aids and more. There are both free and license versions of Sharpcap, with the later containing many of the more advanced features. Sharpcap may now be the most used software for real time viewing.
Chris Wakeman and Steve Massey developed a program called GSTAR-Capture in 1998 for automated and manual capture of video AVI files. It included the ability to capture single frames and had faint object enhancement features including dark frame subtraction. A revised version, GSTAR 4 Capture was released later which added a favorite object, location and equipment database and the ability to record Universal time, RA, DEC, filter used, telescope, and focal length. This version also included a live histogram, occultation time stamping plus the GSTAR-COM camera control for a compete camera control and capture software package.
Also in 2012 William Koperwhats developed the Miloslick software ($49) for many of the Mallincam cameras (Xterminator, Xtreme, VSS, VSS+, etc.). Like Sharpcap, Miloslick provides simple to understand camera controls along with a live image view. And like Sharpcap it provides image capture sequencing, on the fly dark frame subtraction, image stacking, histogram adjustments and more. Lodestar LIve is yet another similar program, developed by Paul Shear in 2014 specifically for the SX Lodestar, providing many of the same image capture and on the fly processing functions as Sharpcap and Miloslick but only for the Lodestar. Eventually Starlight Xpress (SX) bought the software and renamed it to Starlight Live and expanded its compatibility to several other SX cameras.
The Digital Revolution
In 2015 Sony announced that it would cease production of CCDs by 2017 and concentrate on the less expensive CMOS technology which was beginning to match CCD performance and is widely used in commercial digital cameras. While security camera based analog video cameras capable for deep sky observing are still available from Mallincam, Mintron, Watec, Samsung, OCT and PD, there have been no new analog astronomy cameras coming onto the market since the Revolution Imager II and it is not likely that there will be. Instead there has been steady growth of the CMOS based digital cameras from the likes of ZWO, QHY, Starlight Xpress, ATIK, Altair Astro and Rising Tech. Mallincam, GSTAR, and OCT also have new digital cameras for real time viewing as well. Almost all of these cameras use CMOS sensors and all have much higher resolution and larger sensors than the analog cameras. When coupled with the latest software like Sharpcap (and others), real time viewing of the deep sky has evolved tremendously from its roots decades ago. That history is still being written, but you can read more about the early days of this digital revolution on my blog here: the-digital-revolution-in-camera-assisted-viewing.html
The Video Astronomy Innovator Hall of Fame
If I were to make a list of those who have played a significant role in shaping the last 20+ years of amateur video astronomy the following would be my candidates.
Steve Chambers: For leading the charge for extended exposure webcams
Jim Ferreira: For creating the Yahoo Video Astro group and expanding the hobby
SBIG Team: For setting the bar in 1999 with the STV
John Cordiales & Jim Barot: For popularizing the modified security video camera
Rock Mallin: For the 1st color video camera and continuous camera innovation
Steve Massey: For his books on video astronomy and his GSTAR line of cameras
Mike Fowler at OCT: For providing a low cost video camera kit for the beginner
Stephan Lelonde: For providing one of the first camera control programs for free
Robin Glover: For Sharpcap with real time on the fly processing
William Koperwhats: For developing Miloslick SW for the Mallincam cameras
Jim Turner: For creating the live broadcast site Night Skies Network in 2009
photo44 & David B in NM: For popularizing the DIY board camera