I must first explain that I have only attended 2 different star parties in my lifetime, Golden State Star Party (GSSP) and CalStar. I have attended both many times over the last 10 years. You can read my August 2016 review of GSSP in the blog archives. Today, I will discuss CalStar since I just returned from another successful and enjoyable event just two weeks ago.
Calstar is a very informal star party which is held at the Lake San Antonio campgrounds in southern Monterey County. What does that mean? It means that there is no registration, no scheduled star party events, no speakers, no vendors, no hospitality tent, no on-site food, etc. But, there are dark skies and great people to share them with. CalStar is sponsored by the San Jose Astronomical Association and the Left Coast Observers (the people who put on GSSP). They decide on a date, post it on the CalStar web site (calstar.observers.org/ ) and people just show up. It's not free, you do have to pay the park camping fee which is around ~ $32/day for dry camping ($27/day for seniors). The star party is held during the new moon, of course, in Sept or early Oct. When the park was closed due to drought recently, the star party was moved to a nearby religious retreat but it is now back at Lake San Antonio. And, starting this year, a spring CalStar was added in April.
I would estimate that Calstar attracts 100 people tops, sometimes less. Set up is in the "Overflow" campground which is a nice name for what once used to be a ball field but is now a dry, dusty open area. This is where most people set up. This is the strict light enforcement area with most visual observers setting up here. The open area provides a clear view of the skies in all directions with nearby hills and trees limiting views only at very low altitudes. The ground is dirt which is typically dust in the fall given the fact that no rain will have fallen for 5 months. There is a band of trees off to the west which provide shade during the day but do not interfere much with sky views.
There is an section just to the east of the ball field which is about twice as large interspersed with open areas, trees and bushes. This is the late arrival, early departure section with less strict light enforcement so the people set up here are fewer and further in between.
There are porta potties and some old beat up but serviceable picnic tables in the overflow campground. There are also spigots with water which must be boiled before use. No open fires are permitted due to the fire danger, but camping on propane stoves set off the ground is ok. The nearby Redondo Vista campground has bathrooms and shower houses. There are also RV pads with power hookups. This time of year the park is not too densely populated so one can use the power outlet at an empty RV site to recharge their batteries during the day. The park also has some cabins for rent down by the lake. Most people dry camp in tents, cars, trucks or RVs in the overflow campground.
There is a gas station and a small store down by the lake. The store has water, ice, propane and a very limited selection of groceries due to the star party being held at the end of the camping season. There is a full service grocery store just 20 minutes west of the park at a shopping plaza called Heritage Park. It also has a gas station, pizza parlor and coffee shop. The pizza parlor is a great place to visit in the afternoon to cool off when it gets hot, have a salad, burger, sandwich or pizza and watch some sports on the TV, sit and talk with friends, work on your image processing or surf the internet. Paso Robles is 34 miles to the southwest of the park which takes about 40 to 45 minutes to get to. It has a Walmart, Target, several supermarkets, gas stations, restaurants and a nice library, a park and a movie theater.
The weather is typically very hot during the day, in the 90s and even reaching 100 degrees. Night time temperatures are usually in the low 50s or 40s, but I have been there when the temperature dropped into the 30s. It has never rained while I have been at CalStar.
You will see jack rabbits, deer and the occasional rattle snake or wild pig in the park. The park has lots of hiking trails and, when the lake is full there is a beach where you can swim in the lake.
The skies are very dark, I measured 19.74 to 20.11 with my SQM over many different trips. There are some small light domes in the direction of Paso Robles and King City, but these are very low in the sky and not much of a problem. The seeing is usually very good with steady skies being that the park is not far from the ocean as the crow flies.
Now that there are two Calstars every year I look forward to the opportunity to have dark skies and good seeing conditions for the different deep sky objects visible in the spring and early fall.
Many people who do video astronomy like the option of keeping things as simple as possible. This is one reason to choose an analog video camera at a time when many are moving to digital video cameras like those from ZWO. The analog cameras do not require a computer unlike the digital cameras. An analog camera only needs a video display device which will accept an analog input. A light weight 7" or 9" LCD will suffice for viewing by 2-3 people. Simply connect a video cable between the camera and the display to view images. The camera can be controlled with the 5 control buttons on its back, or with a hand control if the camera is configured for one.
But what if you want to ditch the video cable and LCD monitor to further simplify the setup? That is quite easily done with a WiFi Emitter and your phone or tablet making the gear requirements including power all that much simpler.
The WiFi Emitter connects to the camera analog video output and is compact and lightweight enough to be attached to the telescope with the accompanying double sided adhesive. It can be powered with the same 12VDC battery used to power the camera further minimizing the number of required cables. If both the WiFi Emitter and battery are attached to the telescope there will be no need for long cables nor any concern about cord wrap or snags on the mount, etc. The WiFi Emitter works with Android and Apple devices, both phones and tablets and is very simple to setup and connect. With this you can view your video images on your cell phone or tablet completely untethered by cables over distances of 150ft or more depending upon intervening obstacles. I was able to connect to my camera in the back yard from inside my house. If you also have WiFi control for the telescope mount, say through Sky Safari or similar, this setup makes for a very comfortable viewing from inside your home.
You can get a WiFi Emitter from Orange County Telescopes (OCT), the home of the Revolution Imager 1 and 2, for $90. If you are more of a DIY person you can obtain one on Amazon for less than $40 if you search for"AV WiFi Emitter". The WiFi emitter comes with 3 short cables hard wired to the unit, a screw on antenna and an instruction book. The one I bought from Amazon also came with double sided tape which I used to attach the emitter to my camera but you could also attach the emitter to your scope instead. It also included plastic cable ties and another power connector in case I wanted to hard wire the power input to a power source. The emitter sold by OCT does not have the tape, cable ties nor the extra power connector but does include an RCA to BNC adapter which is needed to connect the emitter to the camera. If the emitter you purchase does not have this adapter, you can purchase one on Amazon for a couple of dollars.
The emitter has three short cables. The yellow cable connects to the video output of your camera. This cable has a male RCA jack so you will need an RCA to BNC adapter to make this connection. The other two cables are red and are for the power connections from the battery and to the video camera. Connect the power from your battery to the red input connector which has a female DC plug and connect the other red cable with a male DC plug to the power input of your camera. The WiFi unit runs on 9 -30V DC so a simple 12V battery used to power your analog camera will suffice to power it as well.
A one time setup of the required software is necessary to get started. Using you phone or tablet connect to your APP store, simply search "WIFIAV" software and install it. For iPhones and tablets this would be the Apple Store and for Android phones and tablets this would be the Google Play Store. You will see an icon on your phone that looks like the emitter broadcasting a signal from the antenna. This is the app you will need to launch whenever you want to connect wirelessly to the camera.
When you are ready to connect to your camera, turn on the power to your emitter and camera and you should see the Red LED on the emitter light up. Next, push the button on the emitter and you should see the green "Link" LED on your emitter light up. Now go into your phone or tablet settings and connect its WiFi to "WIFIAV". You may need to type in a password the first time you connect which is probably "12345678", and will be included with the instructions which came with the emitter. Launch the WIFIAV app on your phone or tablet and you will see a screen with 6 blue icons at the bottom and an image from your camera if you are already pointed to an object and focused. Or, you may see the camera menu screen if you have enabled that. Shown here is the camera menu for the Revolution Imager 2. At the bottom of the screen are 6 WiFi controls to capture a video, record to a DVD, save an image, check the emitter signal, go to a file folder which contains the saved images and videos, and change settings. If you plan to only view images live you need not use any of these. If you would like to save images to your phone or tablet just click on the camera icon. You can retrieve these using the file folder icon.
You are now ready to view images from your camera remotely. Just move your telescope to the object of interest and adjust the camera settings as you normally would and you are ready to view objects from planets to DSOs wirelessly on your phone or tablet. While this device makes wireless viewing a simple reality, I have to say that the image quality is definitely not as good as what I can see with the video hard wired to an LCD. I believe there is some video compression which occurs in the wifi transmitter which causes this. Nonetheless, this device enables one to step away from the telescope, view effortlessly from inside or walk around at a public outreach event and share images live without having to crowd around the telescope.
What makes a great star party is a broad question that varies from person to person. However, there are some features which most everyone would agree are essential for a great star party. These would include dark skies and good observing weather. Fortunately, the major star party sites are chosen specifically for their dark skies. Some, like the Okie-Tex, Texas and Nebraska star parties are noted for their extremely dark skies. Weather is another factor which weighs heavily in the minds of star party organizers. That is why you will find the majority of major star parties occur during the months of June-September when the weather is warm and snow is a forgotten memory. A key exception is the Winter Star Party held every February in the sunny and warm Florida keys. There are a lot of other things which distinguish one star party from another which I will divide into 6 areas:
1. Observing Conditions
2. Observing Field
3. Typical Weather
4. On Site Facilities
5. Local Area Amenities
6. On Site Activities
Observing conditions include sky darkness, seeing, light domes, 360 degree clear views, altitude, total hours of astronomical twilight, and number of days the star party is held. Star party sites are typically located away from major cities in in order to provide the darkest skies possible. Sometimes, light domes from nearby small towns can limit visibility in certain directions, but this is usually not a major problem. Clear views in all directions will depend upon the star party proximity to nearby mountains/hills and the presence or lack of shade trees onsite. Since most star parties take place in the summer months, there are significantly less hours of darkness compared to the winter months so it is helpful to have many nights over which to take advantage of the dark skies. Aside from weekend star parties, the major star parties are usually held for 5 days or as long as a week which gives plenty of time to enjoy the dark night skies and daytime activities.
Observing Field features include the size of the observing field and camping area, type of field surface (grass, dirt, hard/soft), availability of shade, and grade of the field. Large observing fields are necessary for plenty of room between individuals for tents, shelters, and cars/trucks/RVs. It is also important to have a fairly level surface for both the telescope and for sleeping. While I have never attended the Nebraska Star Party (I do hope some day to attend) the video on their web site shows that they offer a lot of fairly flat open space for observers to spread out and great unobstructed 360 degree views. The two star parties I regularly attend, Golden State Star Party (GSSP) and CalStar, are held on large, flat fields which provide plenty of space. But both are dirt fields which tend to generate lots of dust. When I get home I have to wipe down all my equipment before I bring it back into my house. I look forward some day to attending a star party on grass. GSSP has no trees to obstruct views, but that also means no shade other than what we bring with us. On the other hand, CalStar has trees scattered throughout which help a lot during the day but can limit sky views. It is a good idea to bring a pop up shelter like an EzUp to provide shade during the day. Many people also use a shade cloth like aluminet which they put over the EzUp, a tent, car, etc. to further cut down on the sun's heating. Aluminet can be found on line, for example www.shadeclothstore.com/depts/aluminetshadecloth.html. This allows you to sleep longer in the morning or stay more comfortable in the afternoon sun. Most star parties provide for sleeping and parking next to one's equipment which is a definite advantage, but some do not allow driving on-off the observing field during the day. This limits the ability to drive to surrounding points of interest and stores during the day, or forces one to park their car away from their setup.
It is no accident that most star parties take place over the warm spring and summer months. Still, weather can turn nasty at any time of the year and one needs to be prepared for rain, cold, and wind. The first night I brought my 11 year old son to a star party a thunderstorm rolled in shortly after sunset on our first night. Nevertheless, we had a great time watching a movie on our portable DVD player while staying dry and warm inside our tent. Sometimes a big rain storm will bring exceptional seeing the next night making the wait worthwhile. Wind can be another troublesome visitor especially in the afternoons at some star parties so be sure to tie down tents and shelters well and be careful with big Dob telescopes. Scopes and anything important should always be covered to keep them cool in the hot sun and to protect them from rain and dust. I use a Telegizmos 365 scope cover which works very well to keep the sun and elements off my scopes, but there are other brands which I assume work equally well and many people use a much cheaper option of a tarp with bungee cords. Dew can be a concern at some star parties as well so be prepared with some sort of dew control for your scope.
Star party site facilities may include bathrooms, showers, sleeping facilities, food, water, ice, power and RV hookups. Since many star parties are held at a secluded open field, standard bathroom facilities are not always available. Bathrooms vary from porta potties to camp style brick buildings with sinks and toilets. Showers may or may not be available on site. GSSP rents a shower truck which provides both showers and a place to shave and brush teeth. Some star parties are held at sites which are campgrounds or some other permanent site which may have cabins, bunkhouses, or Yurts for rent. Food can run the range from a dining hall, a food truck, barbecues or nothing at all. If you are preparing your own food at a star party, it is most likely that open campfires are not permitted so propane stoves will be needed for cooking. Water and ice are sometimes available at the star party site but many do not provide one or both of these. There are some very good, but expensive coolers like the Yeti cooler that will keep things cold for many days. The other option is to drive to a nearby town for additional water, ice and other supplies which can be as much as an hour away. Fortunately, a small town general store is only 10 min away from GSSP and they have water, ice, groceries, and a deli counter which is sufficient to resupply for the duration of the star party. When I retire, I hope to purchase an RV which will make camping at star parties much simpler allowing me to concentrate on observing and meeting with fellow astronomers.
Local area amenities include nearby grocery, hardware and electronics stores, restaurants, gas stations, small town libraries, national and state parks, astronomical observatories, historical sites, quaint towns and so on. Because of the need for dark skies, star parties are found in sparsely populated areas with very small towns nearby. Some are so small you would miss them if you blinked while passing through. But this can add to the enjoyment of getting to see things off the beaten path. I have made it a habit to venture out during the day to the nearby towns for the two star parties I regularly attend so that I am aware of what is available in case the need arrives. Some of these are 5-10min away and others are 1 hr away. Nearby grocery stores are great to provide additional water, ice and food as required. If there is a hardware store or Walmart close by they can be helpful for picking up an essential camping item that you forgot to pack or broke. If there are parks nearby, these can provide a nice opportunity to take a hike through forests, near waterfalls, swim in a lake, etc. while cooling off in less hot conditions. When my son was little, we would drive to the closest town, take in a matinee move and have a nice dinner at a local restaurant. It was a good way to get out of the heat, but I admit I almost fell asleep a couple of times during the movie. If a nearby town has a local library, it can be a place to go and cool off while checking in on the internet.
The overall experience of a star party is further shaped by the on site activities at the star party. These can include guest speakers, equipment vendors, swap meets, workshops, contests, raffles, barbecues, public nights, equipment walk abouts, organized tours, etc. Most star parties will have several of these activities available. The Stellafane Star Party in Vermont is famous for it's fantastic telescope making competition. And it may be the only one to host a lobster dinner. On the other side of the country, the Riverside Telescope Makers Conference (RTMC) held in southern California also provides a great opportunity for telescope makers to show off their handiwork and is noted for the many equipment vendors attending. Some star parties have organized day trips to nearby attractions, especially to a local observatory or historic site. The Almost Heaven Star Party in West Virginia hosts a tour of the Green Bank Radio Telescope Observatory. For many of us, the overall star party experience is also a social one. This is where we meet old friends who we met long ago and may only see once or twice a year the same star party. And this is where we can make new friends as well.
I invite you to make your preferences known by taking a Star Party Survey that I have put together on this web site. It will only take a few minutes and no personal information is required. When enough people fill out the survey, I will post another blog with a summary of the results. The survey can be found under the "More" tab on this web site, or a direct link to the survey is available here: www.californiaskys.com/star-party-survey.html
Nearly two years ago I obtained my first USB camera, an ASI224MC sold by ZWO. ZWO had introduced this camera in July 2015 for $350 and it was an immediate hit with the EAA crowd for good reason. The ASI224MC uses a 1/3" format Sony IMX224 color CMOS sensor with 1.27 Million 3.75 micron square pixels. This provides round, pin-point stars with high resolution unlike typical analog video cameras which have rectangular and much larger pixels. With a high sensitivity rated at 2350mV this Exmor sensor combined with an extremely low read noise of 0.55e to 3e means (depending upon the gain) the camera is well suited to live stacking of many short exposure images. This is very helpful for Alt-Az mounts where single frame exposure lengths are limited by field rotation to around 30sec. When combined with the powerful and free Sharpcap software this camera shows great detail in a wide range of deep sky objects.
Since this is a USB camera and not an analog camera, a computer is required to operate the ASI224. A single USB cable from the camera to the computer is all that is required for both camera power and control. One less cable to deal with and to potentially snag on the mount compared to analog cameras is a pleasant advantage. Sharpcap is probably the most commonly used software for the ASI224 and it provides control over all of the camera menu settings. It provides for image display, capture, histogram stretching, dark frame subtraction and on-the fly alignment and stacking among other nice features. Sharpcap can be downloaded from the ZWO web site along with the native driver necessary to connect the camera to the computer. To use other software you will have to load the ASCOM driver also available on the ZWO website.
Camera settings include an exposure range of 32micro-sec to 1,000sec which makes the camera highly capable for both planetary and deep sky viewing. The camera has a gain setting range of 0 - 450. Lower gain provides higher dynamic range while higher gain provides the lowest read noise. Typically, people report working with gains in the range of 300 - 350. This camera also has the capability for 2x2 binning which makes the pixels effectively 7.5 x 7.5 microns, increasing the sensitivity and speed of the camera at the cost of resolution.
With a sensor diagonal of 6.09mm, the ASI224 has a field of view and magnification factor similar to a 6mm eyepiece. This can make it challenging to place a faint object in the field of view unless the mount's GoTo alignment is very good.
The ASI224 comes with a 2m USB cable to connect the camera to a computer along with a 1 1/4" nose piece adapter to connect the camera to the telescope like any eyepiece. It also comes with an f/2 all sky lens with a 151 degree field of view for detecting meteor showers. This must be removed before attaching the 1 1/4" nose piece. The ASI224 is also designed to work as an autoguider when used with a program like PhD. As such, it has an ST4 guide port and comes with a 2m cable to connect to the mount. While the camera comes equipped with a 1 1/4" nose piece to fit inside a standard 1 1/4" focuser like any eyepiece, the camera can also be inserted into a 2" focuser since the camera body has a 2" diameter collar in the front. This is helpful to achieve additional in-focus when using Newtonians and Dobsonians which are not designed for astrophotography. In addition, the front of the ASI224 has an M42 x 0.75 thread making it ready to be used with T-adapters.
The ASI224C was upgraded in April 2016 with anti-amp glow circuitry. Amp glow is caused by the heat produced in the read out circuit of the sensor during long exposures and is common in analog video cameras. It produces a bright glow at the edge of the image making that part of the object appear over-exposed. Short exposures and/or dark frame subtraction are commonly used to eliminate or minimize the impact of amp glow. With the ASI upgrade this is no longer necessary. The USB connection was also upgraded from USB2.0 to USB3.0 to support better download rates. In addition, the price of the ASI224 has been reduced to $249.99 as other cameras with the IMX224 sensor have become available. A cooled version of this camera, the ASI224MC-C was available for a while and sold for $599, but has since been discontinued.
As can be seen from the images here, the ASI224MC camera performs very well for all sorts of deep sky objects. It produces nice round, pin point stars and has very good color saturation. All images were captured using Sharpcap and have had no post capture image processing. What you see here is what you would have seen on my computer screen live.
With the popularity of the ASI224MC, many other camera suppliers have introduced versions of their own with the IMX224 sensor in the last couple of years. QHY makes and sells a cooled camera with the Sony IMX224 sensor for $669. It's 2-stage regulated TEC cooler can cool to 40deg. C below ambient. It also has the anti-amp glow circuit, a USB 3.0 computer interface and a 128MB image buffer to prevent lost frames when capturing images with a high frame rate. This camera has exposure settings of 7micro-sec to 400sec and the same read noise as the ZWO camera. With the active cooling, the QHY camera body is significantly larger than the ZWO but it also has an M42 x 0.75 thread making it ready to be used with T-adapters.
While ZWO and QHY make their own cameras with the Sony IMX224 sensor, there are many other retailers who appear to re-brand cameras from a Chinese company called Touptek and sell them under their own label. These include three cameras from Rising Tech in China, and one each from Mallincam in Canada and the U.S., Orange County Telescopes in the U.S. and Altair Astro in the U.K.
Rising Tech sells three versions of the IMX224 based camera. The USB 2.0 version, Model GPCMOS, comes without the amp glow reduction and sells for $162 making it the cheapest IMX224 based camera currently on the market. This camera also has a lanyard which can be used as a safety strap to attach the camera to the scope. Model G3M224C has the USB 3.0 connection and the amp glow reduction circuit for $245 and has a slightly larger body than the GPCMOS camera. However, both models are small bullet shaped cameras which can fit well inside a focuser making it easier to achieve focus with Newtonian telescopes which are not designed for astrophotography.
Model G3-1200KPA also has both the USB 3.0 and the amp glow reduction, but comes with a cooling fan for $295. The G3 also has a much larger camera body and has M42 X 0.75 threads making it straightforward to attach a t-adapter to the camera. All cameras come with camera control software called Rising Sky, which appears to be a re-branded version of Toupsky camera control software. Toupsky has many of the same features found in Sharpcap such as image display and capture, on the fly stacking, dark frame subtraction, histogram stretching, etc.
Mallincam's IMX224 camera is called the Skyraider AG1.2c, and comes with a USB 2.0 computer connection, MallincamSky software which looks like re-branded Toupsky software for $250. The Skyraider camera body has built in cooling fins to facilitate passive camera cooling and also has a lanyard which can be used as a safety strap to attach the camera to the scope. The web site makes no mention of amp glow reduction so I assume it does not have it. The bullet shaped front also enables this camera to fit further into a focuser making it possible to achieve focus where some of the larger cameras cannot.
Altair Astro's GPCAM3 224C has a USB 3.0 computer interface and comes with a UV-IR filter and AltairCapture software. The camera body has cooling fins and the same bullet shaped front as some of its competitor. The GPCAM3 sells in the U.K. for £249. It also comes with a 1 year license for the Pro Version of Sharpcap.
Orange County Telescopes sells the Revolution Imager 224 (R224) but does not hide the fact that this USB 2.0 camera is manufactured by Touptek. The R224 makes no mention of the amp glow circuitry, comes with the ToupSky software and sells for $250. The R224 is another of the bullet style cameras. It comes with a UV-IR filter, a 0.5X focal reducer and a soft carrying case for the camera, cables and accessories.
Maximum exposures are 1,000sec for all of these cameras, but the stated minimum exposures vary. While several of the camera suppliers do not specifically mention the read noise, I believe these all have the same read noise specs which are determined by the CMOS sensor itself. All of these cameras come with a 1 1/4" adapter to connect the camera to a 1 1/4" telescope focuser and a USB cable to connect to a computer. They also all have the standard ST4 guide port to use as an autoguider and guide cable. Some come with additional adapters and some also have T-threads to attach T-thread adapters. All should work with the Sharpcap software but may need the ASCOM driver to do so. Any of these cameras should function well as a low cost camera for real time viewing of the deep sky with the added advantage as an autoguider if and when you move on to a more expensive camera.
Newtonian and Dobsonian telescopes are commonly used for astronomy because of their relatively low cost and fast focal ratios, typically f/5 or faster. Dobsonians are just Newtonian optical tubes on an Alt-Az mount after the style made popular by John Dobson. There is a critical consideration when choosing a Newtonian for deep sky video astronomy, Electronically Assisted Astronomy, or Near Real Time Viewing, whichever you call it. Newtonians and Dobs, unlike Schmidt Cassegrains and refractors, do not have a lot of in-focus travel which is required to focus analog cameras like the Revolution Imager, Mallincam Xtreme, Strellacam, Samsung, etc, or digital USB cameras like those from ZWO, Atik, Rising Tech,etc. This is especially the case if using a focal reducer to speed up the optical train and/or achieve a large field of view. When there is not enough focus travel, modification of the optical tube may be required to achieve focus with a camera. Fortunately, there are many Newtonians and Dobs which are able to achieve focus with a camera without the requirements for scope modification. These are often, but not always, sold as imaging Newts. The table below shows a list of Newts and Dobs that have been reported on Cloudy Nights as compatible for use with various cameras without modification to the scope. There are certainly many more than listed here, but these are the ones I am currently aware of. They span the range from 100mm aperture to 305mm and all are fairly fast even without a focal reducer. Several of these scopes have also been verified to work with a focal reducer without the need for any modifications. This is shown in the "Focal Reduction" column.
When a Newtonian scope does not have enough in-focus travel to work with a video camera, there are two options. First, modify the scope by moving the primary mirror closer to the secondary. Some truss tube collapsible scopes make this easy to do with a specific configuration for imaging which brings the primary mirror closer. But the solid tube Newtonians do not have this option and require mechanical modification to bring the mirror closer. Many have done this modification to make their existing Newts compatible for use with cameras. It will require re-doing the collimation, but Newts seem to require frequent collimation anyway.
If shifting the primary mirror position is not something that you are comfortable with, there is another option. There are many bullet style cameras with 1 1/4" diameters either their full length or enough of it that they can fit further down the focuser, bringing the camera's imaging sensor close enough to focus, even with the addition of a focal reducer. Examples include the Starlight Xpress X2C, Revolution Imager IMX224, and the Rising Tech IMX224. It has been reported that this works with the 8" f/6 and 12" f/5 GSO Dobsonians along with a 16" f/4.5 Meade Lightbridge Truss Dob. These can even achieve focus with a 0.5X focal reducer by using a 2" negative profile adapter like this one from ScopeStuff which allows the camera body to slide even further inside the focuser.
Even though cameras like the Mallincam Micro Ex, LnTech300, Revolution Imager 1 are not bullet shaped, they are small enough to fit down inside a 2" focuser allowing these cameras to achieve focus with many Newts. However, with both the bullet style cameras and these small rectangular cameras, be careful that they do not slip down and contact the secondary. The 1/4" x 20 mounting bracket found on the Micro, etc. is useful as positive stop to prevent this from happening.
It has been nearly 20 years since SBIG in Santa Barbara introduced the STV for the tidy sum of $1995. This video camera was marketed as both a deep sky video camera and a stand alone guider. At its heart is a Texas Instruments TC-237 1/3" format B&W CCD sensor with 656 x 480, 7.4micron square pixels. In retrospect, for its time, the STV was revolutionary. From my research it the first video camera to be capable of deep sky video without modification, years before the Stellacam, Mallincam, Samsung, Mintron or Watec cameras. Not only that, it came with an amazing list of features which we now take for granted in our CMOS based video cameras but which did not become widely available until the past few years. This includes, exposures up to 60 minutes, manual gain (1x or 2x), thermo-electric cooling, 1x1, 2x2 and 3x3 internal binning, internal stacking and alignment of successive frames called "Track & Accumulate" and an optional 5.3" LCD monitor. In addition, it had an internal filter wheel with a green filter to act as a "neutral" density filter when viewing the moon, and an opaque filter to support internal automatic dark frame subtraction. An optional color filter wheel was also available for color imaging. The unit came with 2MB of internal memory to save up to 14 images which could be downloaded to a computer later.
The camera came with a rather large control module with buttons and knobs to scroll through the camera menu and adjust camera settings. The settings were viewed on a small, two line LCD display. An optional 5" LCD monitor showed the live images. Accessories included a very thorough manual, a 110VAC to 12VDC transformer, RS232 cable to connect the control module to a computer, RJ11 auto-guide cable, red screen shield for the LCD monitor, 1.25" nose piece adapter, software for remote operation of the camera via a computer, and copies of CCDSoft and CCDSharp. Additional options included an eFinder tube assembly with a focal reducer to turn the camera into a stand alone guider, the previously mentioned color filter wheel, adapters for 35mm cameras and a hard carrying case with custom cut foam.
I have seen some surprisingly good images of galaxies and nebulae taken with this camera and posted on the internet. So, as a student of deep sky video history, I recently purchased one of these cameras on Cloudy Nights to see what it could do for myself. First of all, everything is big from the camera, to the control box to the power supply. I guess this is not a surprise given the state of the art of electronics 20 years ago. Second, a short read of the quick start guide in the manual enabled me to begin taking images in quickly. The controls are quite easy and mostly intuitive. When in the imaging mode, the two round knobs on the front panel are used to adjust the brightness and contrast of the image as viewed on the LCD. To capture images with this camera, I used the video out port on the control module and fed the signal through a video capture device to my computer which was running Sharpcap software. I used Sharpcap to view and capture the images shown below.
So far I have only tried the camera with an ES 127mm, f/7.5 Apo refractor, but have been pleasantly surprised with the results. I have used the camera both with and without a generic 0.5X focal reducer and without any filters. I will note, the images as they appear on the SBIG LCD monitor are noticeably better than the images on my computer screen. I use the same video cable and Pinnacle Dazzle 100 to send the signal to my computer as I do with all my other analog video cameras, so I am guessing the difference is due to the output on the SBIG control module.
Since it is the Christmas season, Orion is an obvious target. Below is a single frame, 10sec image of M42 taken with a gain of 1X. While the core is blown out, we can see significant detail in the nebulosity. Next is a 30sec single frame image of the Flame Nebula. The 5.6mag variable star NSV16638, which is just on the edge of the top of the image makes it difficult to avoid washing out the nebula but I was still able to see it clearly. The HorseHead nebula is difficult to see in a light polluted back yard, especially without filters, but this 60sec image shows it quite well.
One of my favorite galaxies this time of the year is M82, the Cigar Galaxy. The STV had not trouble bringing out the split in this galaxy even at a few tens of seconds. The image shown here used the Track & Accumulate feature, aligning and adding 5 x 30sec frames for a total of 150sec. Notice how nice and round the stars are and compare this to the elongated stars in the 60sec single frame of the HH Nebula. I would say that the T&A feature works quite well, and this was available almost 20 years ago. Next are two 60sec single frame images of M82, the first without the internal dark frame subtraction and the second with dark frame subtraction. Notice the dramatic difference. And, I did not even have to get up and cover and uncover the scope to do this. It was all automatic one I check yes in the camera menu for dark frame subtraction. Since this CCD sensor is nearly 20 years old, I have no way of knowing if this is typical of the number of hot/warm pixels when the sensor was new. Nevertheless, dark frame subtraction is able to take care of the objectionable noise.
All in all, I am very impressed with what this camera can do. When I realize that this camera had all of the extra features in 1999 that most cameras/software did not have until recently I am even more impressed by SBIG. If not for the much older vintage (1996) and smaller format (1/3") CCD (TC-237), this system would still be a competitive analog video performer today. Not to mention, that many people still use this as a stand alone auto guider for their long exposure imaging. No wonder I had a tough time getting someone to part with this.
Next time I have clear dark skies, I will see if I can improve the images, especially the star bloat with filters. And, I would like to try the camera out on my 9.25" SCT which will pull in more light than the 127mm refractor.
The question of which type of video camera one should buy for deep sky astronomy, an analog camera like one of the Revolution Imagers or Mallincams, or a digital camera like a ZWO ASI224 or one of the other IMX224 based cameras often comes up. The simple answer is that it all depends upon personal preferences and objectives. Below I will outline the main differences between the two types of cameras. I own and use both types of cameras myself so I am trying here not to be biased one way or another, nor trying to conclude which one is best as this depends upon the individual. I am just stating the facts as best as I know them from my own personal experience.
For clarification I will note that all cameras are actually analog since the chips used, whether CCD or CMOS, accumulate electrical charge proportional to the number of photons of light that strike them. This charge is converted in the camera to a digital count in an analog to digital converter. Additional processing of that digital information takes place inside the camera circuitry. The "digital" cameras then output a digital signal, whereas the "analog" cameras convert that digital signal back to an analog signal which they output.
The least expensive digital cameras that one would likely use for near real time deep sky video are the IMX224 based cameras like the Mallincam AG1.2c ($250), Altair Astro GPCAM2 - ($279 Canadian), Generic GCMOS available from a number of non-Astronomy companies on AlieExpress (~$200) and the ASI224 from ZWO at $299. They come with everything needed to get started (camera, USB cable, nose piece) except a focal reducer which can be found on Ebay for $15 for a 0.5X version and a computer which is required to power, control and view images from the camera. If you already have a computer you are set. If not, you will need at least $150 more for a low cost laptop. Other digital cameras used for deep sky video from ASI, Starlight Xpress and Atik range up to $1000 and include larger and more sensitive sensors with more pixels for higher resolution and faster acquisition times. Some come with thermoelectric cooling to minimize background thermal noise. And the Starlight Xpress and Atik cameras come with their own control and imaging software.
The least expensive analog cameras are the Mallincam Micro and the Revolution Imager which can be obtained for $100. But then one must add a focal reducer for $15 on Ebay for a 0.5X version, a power/video combo cable and power adapter, both also available on Ebay for around $15 or from any camera which sells security cameras. If you have a television with an RCA video input, you can use it as your monitor or you can purchase a 9" LCD monitor on Amazon for around $60. Make sure it can display in a 4:3 format as the 16:9 format will cause round objects like the moon to appear oblong. The Revolution Imager comes as a kit for $300 which includes the camera, nose piece, all cables, a rechargeable Li-Ion battery, focal reducer, 7" LCD monitor, IR filter, hand remote and carrying case. The Mallincam kit includes the camera, nose piece, all cables, focal reducer with an additional spacer, 7" LCD monitor, hand remote. More expensive analog cameras like the Mallincam Xtreme or Xterminator are available for prices ranging up to $1800 and include larger and more sensitive sensors, thermoelectric cooling and computer control.
Analog cameras have a lower resolution than digital cameras since they typically use sensors with fewer than 600k pixels while most digital cameras have 1.3Mega pixels or more. Also, the pixels in digital cameras tend to be smaller (3.75 to 6.45 microns) than those in analog cameras ( 5 to 9.8 microns). In addition, the pixels in analog cameras are not square while those in digital cameras are square. Thus, by using smaller and square pixels, the stars in digital camera images will look round while those in analog cameras usually do not. Images from digital cameras can also handle more zoom because of the higher pixel count. That is not to say that images from analog cameras are objectionable, just that those from digital cameras generally have more of a picture quality to them.
In general, but not in all cases, the sensors used in analog cameras are more sensitive than those used in digital cameras. This, along with the larger pixels typical for analog cameras means that shorter exposures are required with most analog cameras for the same image brightness. This puts less strain on the requirements for the mount and the degree of polar alignment required. Thus, analog cameras are a good choice for those with expensive mounts, or with less interest in spending the time and effort to obtain a very good polar alignment.
Digital cameras need only 1 cable for power, camera control and video output. Analog cameras need at least two cables, one for power and one for video output. However, combo video/power cables are quite common and allow for a single cable running from the camera to the computer or monitor. Another option with video cameras is to use a rechargeable Li-Ion battery attached to the scope or mount with Velcro and a very short power cable from the camera to the battery. Then only a separate video cable needs to be run from the camera to the computer or monitor. The Revolution Imager kit ($300) comes with a rechargeable Li-Ion battery and short power cable. 6.8Ah Li-Ion batteries or larger can be found on Amazon( $20) along with short power cables (<$10).
Both analog and digital cameras draw very little current, less than 500mamps, unless they have active cooling. In that case, they will draw up to about 2amps. Digital cameras like the cooled versions of the ASI224 or ASI1600 require an extra power cable and a 12VDC 2amp power source for cooling while cooled analog cameras like the Mallincam Xtreme need no extra power cable or supply.
6. Camera Control
Digital cameras are controlled through the included USB cable with software on the computer. Digital cameras like the Mallincam AG1.2c, AltairAstro, Generic GMOS ICMX224 cameras, ATIK Infinity and Starlight Xpress Ultrastar or Lodestar come with proprietary software for complete control of the camera menu. Analog cameras and the ZWO digital cameras do not come with their own software. However, ZWO cameras can be controlled with freeware like Sharpcap.
Analog cameras have 5 buttons on the back of the camera for control of the camera menu, but these buttons are small and can be difficult to manipulate in the dark and cold and do not allow remote operation. Alternatively, analog cameras can also be controlled with a wired remote. The Mallincams use a separate cable attached to the back of the camera with a hand remote control (costs extra unless camera is purchased as a package). The Revolution Imager uses a UTC hand controller (costs extra unless camera is purchase as a kit) which is connected in line with the video cable so it does not require an additional cable to hang from the camera. Some analog cameras, like the Mallincams can also be controlled through a computer with an optional computer control cable and the free Mallincam Camera Control software. There are also DIY instructions on Cloudy Nights to add wired hand or computer control as well as wireless control of analog cameras.
7. On the Fly Image Processing
On the fly image processing including stacking (some with frame to frame rotation and translation for precise registration, histogram adjustments), dark frame subtraction and image capture is available with both analog and digital cameras depending upon the software used. The software included with the Mallincam AG1.2c, AltairAstro, Generic GMOS ICMX224 cameras, Atik and Starlight Xpress cameras will perform on the fly image processing. Sharpcap will perform all of the same functions for analog cameras and digital cameras. To use software like Sharpcap with an analog camera, a video capture device ($30) is required to connect the camera video output to a computer ($150), but no additional cable is needed.
So, if you defintely do not want to use a computer for EAA, your only choice is an analog video camera. If you want high resolution, you will have to choose one of the high end digital cameras like the Atik Infinity, ZWO 1600 or Starlight Xpress UltraStar. Entry level cameras can be obtained for under $300 including all necessary accessories for both the analog and the digital versions.
Over the years I have always used an EQ mount along with my Celestron 9.25" SCT, Celestron 14" SCT with Hyperstar or my Orion ED80 (for wide field images) when engaging in deep sky video. However, such setups are heavy, not easy to transport when traveling to a dark site or just setting up nightly in one's own back yard. Also, these scopes and mounts are fairly expensive, counted in the many thousands of dollars not including the video camera. In addition, polar aligning an EQ mount is not everyone's cup of tea, let alone accurately aligning it for long exposures.
There seems to be a lot of interest lately in very light and highly portable Electronically Assisted Astronomy (EAA) setups which do not cost a fortune. Some are experienced astronomers who are downsizing as they are getting older and finding it more difficult to transport and set up heavy equipment. Some want a simple setup for public outreach. Others are new to astronomy and want to start with something simple to setup, easy to get started and relatively light on the wallet. To address this trend, I paired a Celestron SE6 which is a 6" SCT on an Alt-Az mount with two different types of low cost video cameras, a Revolution Imager 2 (R2) and a ZWO ASI224MC.
Why the choice of the SE6? Alt-Az mounts pose a fundamental challenge since they don't track along the Celestial Equator like and EQ mount does. This means that objects do not stay centered in the field of view (FOV) like they do in a polar aligned EQ mount. Field rotation, which causes stars to become elongated and blurs detail in extended objects like galaxies and nebulae, can limit exposures to as little as 10 seconds in some parts of the sky. The length of the exposure possible before field rotation becomes a problem depends on the focal length of the telescope, the Altitude and the Azimuth of the object being viewed, and the observer's latitude. You can read more on this in the "Quick Start Guide" section of this web site. Fortunately, recently released EAA software has the ability to extend exposures to several minutes without field rotation ruining the image.
Second, Alt-Az mounted scopes are typically much less expensive than EQ mounts which addresses the lower cost factor. The 6SE, which belongs to the Celestron Nexstar series of scopes typically sells for $799 including the mount, tripod, SCT and accessories. I have seen it on sale for $699. The 5SE, with a 5" SCT is $100 cheaper.
Third the 6SE meets the objective of lightweight and portable with a weight of only 21lbs counting the mount, tripod and scope. The 5SE is only 17.6lbs. Because of this and the fact that the mount and scope are fairly compact, I was able to leave everything assembled and move it back and forth between my house and the yard easily and quickly. For transport to a dark site, the scope disassembles into three pieces (tripod, mount, SCT) and easily fits into the trunk or back seat of practically any car. A plastic accessory box serves to hold the camera and its accessories.
Fourth, there is no requirement to polar align an Alt-Az mount which makes it much easier and faster to setup than an EQ. First, level the scope. Next, the Celestron Nexstar series of scopes has a Skyalign routine which requires sequentially locating three bright stars or planets using the included unity Red Dot Finder and the hand control to move the scope in Altitude and Azimuth. Each star must be centered in the FOV of the camera or an EP. Once all three have been found, Skyalign will determine the scopes orientation and even tell you which three objects you found. To obtain a good alignment, the three objects should be widely spaced and not in a straight line from one another. With the scope aligned, it will be able to GoTo nearly 40,000 objects in its on-board memory and will be able to place most objects in the FOV with a 12mm or larger EP. For video cameras with 1/3" CCDs, I found that some objects were just slightly out of the FOV due to the small size of the CCD chip, but typically they are outside the FOV in the same direction which makes it easy to make small adjustments with the hand control to get the object centered. With practice, the Skyalign GoTo alignment can be completed in less than 10min.
Fourth, the 6SE comes with a 6" SCT which I think is sufficient for observing all of the Messiers and many of the Herschel objects with either of the two cameras listed above. An 8" version will show much more and is recommended if it is within budget since it only adds 3lbs to the total weight. The 5" version will still provide pleasing views for those on an even tighter budget.
Why the R2 and the ASI224MC? Simply cost and performance. The R2 which comes as a kit costs $300 and the ASI224 is $349, making these two of the lowest cost options for EAA. Both perform extremely well, each offers advantages over the other and both are color cameras.
The R2 is an analog camera which comes as an all-in-one kit including a 7" LCD, Li Ion battery, focal reducer, UV-IR filter, hand control and cables. This is everything you need to get up and running immediately. And, it has a reasonably sensitive CCD which will provide pleasing images of many deep sky object. The camera settings are changed using the hand control and on screen menu display. Since it is an analog camera it can be hooked directly to the LCD or your own larger television set and does not need a computer to work. This makes the combination of this camera and the 6SE highly portable. On the other hand, with the addition of an inexpensive digital capture device the R2 can be connected to a computer to capture and process images. With free EAA software such as Sharpcap, the maximum exposure can be extended to several minutes as will be explained shortly.
The ASI224MC is a USB camera which comes with a USB cable, C-Mount and T-mount adapters and an All-Sky lens for wide angle shots of the night sky. A computer is required to adjust the menu settings, view, capture and stack images live. A single USB cable connected to the computer, powers the camera, sends images to the computer and provides control of the camera menu. Sharpcap can also be used with the ASI224MC to do everything it can with the R2, plus it will control the camera settings as well. If you prefer, a version of the software package AstoLive is available free to anyone purchasing a ZWO camera like the ASI224MC. With a very low readout noise, the ASI224MC is well suited for stacking of many short exposure frames. And, if you decide to move up in cameras later, the ASI224 can be used as an autoguider. The ASI224MC will require the purchase of a focal reducer to improve image detail and one equivalent to that provided with the R2 can be purchased for less than $20.
I attached the R2 to the SCT with a 1.25" diagonal to give enough space for the camera to clear the mount when pointed at the zenith. The Hand Control for the R2 is attached at the back of the camera when I view on the LCD. When I use a computer, I use a longer video cable and connect the Hand Control next to the video capture device at the computer. Using these two different methods enables me to have the Hand Control right next to me. For the LCD, I bent the mounting base to the curvature of the the optical tube assembly (OTA) and glued a piece of soft foam to the bottom of the mounting base to avoid scratching the finish of the OTA and held it in place with Velcro straps. I can change the angle of the monitor to compensate for different OTA orientations. I mounted the battery to the arm of the Nextstar SE mount and ran the power cable to the monitor and camera using the included power splitter cable. The mount can be run on its own internal batteries or with an external 12V battery. With this setup, I can leave everything connected and stored inside my house and very easily carry it outside and set it up, including the GoTo alignment in about 15 minutes.
The ASI224MC can be attached directly to the visual back without a diagonal and will easily clear the base of the mount when pointing at the zenith. The ASI224MC requires the use of a computer and software to control the camera, view and save images. The included USB cable simply connects to one of the USB inputs on the computer. With the exception of the computer, this setup is even simpler than with the R2. But then, some folks do not want to have to deal with a computer, especially in the field.
When using a computer, the last important piece to this EAA setup is the free software, Sharpcap. Sharpcap not only allows one to view, capture and adjust the brightness and contrast of images live on the computer screen. It can also stack frames on the fly, translating and rotating successive frames to align them to the original frame. This greatly extends the exposure times possible with an Alt-Az mount into the many minute range. Sharpcap also has a histogram feature which enables stretching of the image to bring out more detail and darken the background sky. All of this on the fly, and for free.
So there you have it, two light weight and highly portable EAA solutions which won't break the bank. What are you waiting for, get going!
If you live in California, Oregon or Nevada and have not already attended the Golden State Star Party, I highly recommend it. Why? Simply put dark skies, lots of other like minded astronomers and interesting side trips to keep one busy during the days.
GSSP is held every summer between mid-June and mid-July to overlap the closest new moon. It runs for 5 days and 4 nights on Wed. through Sun. or Sun. through Wed. In 2017 it will be held Wed. June 21 through Sun. June 25, with the new moon on Fri. night. GSSP is held in northeast California in the town of Adin, population 272 at Latitude 41deg 8’ 7.35”N, Longitude 120deg 58’ 42.95” W at an altitude of 4310ft. The star party takes place on the Frosty Acres Ranch, a cattle ranch with a dirt surface broken by tufts of range grass and the occasional dried cow patty.
GSSP is 226 miles north-east of Redding, Ca, 102 miles south-east of Klamath Falls, Ore and 153 miles north-west of Reno, Nv. This puts it more than 100 miles from the nearest large light dome which makes for very dark skies with SQM readings typically 21.64 to 21.83. The Milky Way glows brightly and is an awesome sight away from city lights. In addition to dark skies, this site has clear vistas in all directions, including a nice view of Mt. Shasta covered in snow to the north-west.
In addition to the dark skies GSSP is home to between 300 and 400 astronomers and their families, along with telescopes of every kind. There are experts who are willing to share their knowledge to beginners and other experts alike. It seems like they bring every type of telescope, mount, camera and accessories known to the industry. This makes for a great opportunity to see and even try out equipment before you buy. This star party is family friendly - my son started attending at age 9 and looks forward to going back when he can.
There are some important things you need to know if you plan to attend. Registration for the 2017 start party will begin in January 2017 on-line at www.goldenstatestarparty.org/. The fee for 2016 was $75 for the 5 days and 4 nights which includes the on-site shower truck with showers and sinks, porta potties, a hospitality tent, a battery charging station and the final morning pancake breakfast. There are usually two evening barbeques and t-shirts which require additional charges. Activities include guest speakers, a raffle, a swap meet, a telescope walk about which included 2 home-made bino telescopes this year, and 4-5 telescope dealers.
You should also know that day-time temperatures are typically in the high 90s and there is no shade. Make sure that you have plenty of water and bring some form of shade such as an EZ-Up or Aluminet to stay "cool" during the day. And bring a cover for your scope and strong stakes for your tent or EZ-Up since it typically gets windy in the afternoon. Nights are pleasant with lows in the low 50s or 40s. In the 6 years I have attended, I think we were rained out 4 nights total. The skies are usually very clear, but as with any place, it all depends upon the weather. Since this star party is held in the summer, it doesn't really get dark until around 10PM and then the sun comes up around 5:30AM. Seems short, but I have never felt I did not have enough time under the stars, especially since there are 4 nights to view.
You have to bring your own sleeping accommodations as this is a camping star party. You will see lots of tents, campers of every size and shape, along with small and very large motor homes. I have camped in a tent, slept in my van and stayed at a nearby hotel. As for the hotels, there's one in Adin and one in the other nearby town of Bieber but both are annually booked and having waiting lists so don't count on them. Be prepared for the early sun rise and note that it starts to get hot inside a tent or car by 8AM which can make it hard to sleep in. It's a good idea to have sun shade material like Aluminet to help keep your accommodations as cool as possible.
You may cook your own food, but no open fires are allowed. You can also sign up for the barbeque nights or drive to one of the nearby towns for dinner. The town of Adin is 10min from the site and has a small general store and one hamburger/ice cream shop. The general store will have typical grocery items, bags of ice, water and even wine. They also have a deli counter which is great for lunch. The Oney serves hamburgers/hot dogs and ice cream, and also has barbeque chicken and ribs on Fri. and Sat. There is also a gas station/convenience store in Adin.
The nearest restaurants and full service grocery store are about 30min west of Adin. The nearest big city, Susanville, is 67miles to the south east where you will find a Walmart, pharmacies, Radio Shack, full service groceries, restaurants and two movie theaters. The movie theater is a nice place to cool of and catch an afternoon nap.
Plan day trip or two to get out of the direct sun. There is a community pool in the town of Bieber, 15min to the west. In recent years, either the town of Bieber or Adin has held a community fund-raising festival with food and music during the star party. I think they time it when there are 300 - 400 more folks in town. There are some great day trips to nearby outdoor adventures. Lassen National Vulcanic Park is 82 miles away and offers Manzenata Lake and lots of hiking trails, as well as, Mt. Lassen. 50 miles due west near the town of Burney is Burney Falls, one of the prettiest waterfalls in California. It also has some nice hiking trails. If you go, you can plan to have lunch or dinner in the town of Burney or pick up some groceries as it is only 10min away. On the way to Lassen is the Hat Creek Observatory home to an array of Radio Telescopes. To the north is Lava Beds National Monument with lava tube tunnels you can walk through. And, the entire area around Adin is nestled next to the Modoc National Forest. So, there is lots to do during the day if you just want to get away.
If you haven't been to the Golden State Star Party, I strongly suggest you give it a try in you live within driving distance. I don't think you will be disappointed.
A beginner getting into video astronomy typically purchases a camera with a few essential accessories such as power and video cables and a nose piece adapter. However, this leaves it up to the individual to research and purchase additional important accessories such as a focal reducer, filters, a monitor and a 12V power source. For many of us this is not a problem, but for some it is a hassle and can be downright confusing considering the different decisions that have to be made and the fact that these have to be purchased from many different sources. This may discourage some making them choose to move onto something else.
Fortunately, last year an astronomy supplier in Southern California, Orange County Telescopes (OCT), put together a complete package with all the necessary pieces required to get started with no hassle and at a reasonable cost of $300. The package was called the Revolution Imager and it contained an Lntech 300 PAL video camera, power and video cables, a 0.5X focal reducer, an UV-IR filter, a 1.25" C-Mount adapter, a 7" LCD monitor, a hand-held camera remote control, a 12V Li ion battery with charger and a convenient shock resistant carrying case. Here, in one complete package, was everything needed to get started viewing planets, galaxies, nebulae and other deep space wonders except the telescope and mount. The Revolution Imager apparently was a hit with beginners, as well as, those who already had a video camera but wanted something simple for themselves or for use at public outreach events. Eventually the packages sold out as production of the Lntech 300 came to an end.
Fast forward to May 2017 and OCT has once again put together an all-in-one package after finding a replacement for the original camera. The new package comes with all the same accessories as before and still sells for $300. It is called the Revolution Imager 2 (R2). The new camera uses the same Sony ICX811 PAL 1/3" CCD as the Lntech 300 which is one of the more sensitive CCDs used in video cameras today. It outputs video with a resolution of 720 x 576.
So how does the R2 camera and all of the accessories perform? In my opinion, quite well. I tested the R2 from my backyard with both a Celestron 9.25” SCT on an equatorial mount and a Celestron 6” SCT on an Alt-Az mount and obtained very nice images of globular clusters (M3, M5, M13), galaxies (M51, M63, M64, M66, M87, NGC5907) and the planetary nebula M57 with both setups. I initially viewed images directly from the camera on the included 7” LCD monitor and powered both the camera and monitor with the included Li Ion battery. Later, I used the free software, Sharpcap, to save single frame images to share as I am doing here. I also used the live stacking feature available in Sharpcap to obtain even more spectacular detail by extending the exposure time beyond the camera’s maximum of 30sec. (5 sec exposure with 6 frame averaging, called DNR).
At a recent in town star party I brought the R2 package including LCD monitor attached to the top of the 6” SCT to share its capabilities with members of our local astronomy club. I used the camera without a computer, using only the camera’s own internal menu which I controlled with the included wired hand control and the monitor’s brightness and contrast controls to obtain the best looking images on the screen. Beginners and old-times alike were impressed with the images that we could see of DSOs on the LCD monitor with the R2.
I also had a chance to try out the camera on the 6” SCT on the Alt-Az mount at a dark site and it provided amazing images of most of the above DSOs along with some really colorful nebulae such as M8, M16, M20 and M27.
Like all analog video cameras that are really security cameras re-purposed for astronomy, the menu of the R2 can be confusing. But, to get started one really only has to focus on 3 main menu items and ignore all the rest. First is the exposure which has a maximum of 5sec (256X) and steps down by factors of 2 from there, i.e. 2.5sec (128X), 1.25sec (64X) etc. Below 1/25th sec (2X) the exposure settings are shown as 1/50, 1/100, 1/250 … 1/100000. For DSO you will want to stick with exposures somewhere between 64X and 256X. The shortest exposures are useful for planets, the moon and the sun (with appropriate solar filters, or course). To change the exposure select the “Scene Select” menu item "Custom" to get to “Shutter/AGC” where I suggest you start with “Fixed” mode to set both the exposure and the gain. Gain ranges from 6dB to 44dB. In my case, 30 or 36dB seemed to be optimal settings to boost signal without creating a washed out background. Exposure and gain settings will vary with sky conditions, location and telescope so you will have to experiment to find what works best for you.
The third setting which is important to take advantage of is the within-camera frame averaging, or DNR. This can be adjusted from 0 to 6 and has the effect of averaging successive frames to smooth out the background and sharpen detail. So, if exposure is set to 5sec and DNR is set to 6, the camera will output an image after 5 sec, but will output an updated and improved image every additional 5 sec. After 30 sec the image will look the same at successive refreshes. If using an Alt-Az mount or a poorly polar aligned equatorial mount, you may not be able to use the maximum DNR and avoid star trailing. Experiment with this also.
What do I like best about the R2?
1. The camera is a very good performer, providing some of the best images I have seen from a camera in the $300 or under price range.
2. The included 4.8AmpHour Li Ion battery is small and light weight yet can run both the camera and LCD monitor for 5 hours on a full charge. It will certainly power the camera alone for more than a full night's observing. For $50 you can buy a 9.8AmpHour battery for longer running time.
3. Everything comes neatly packaged with most cables already connected between components to minimize confusion. Just
4. OCT has an excellent reputation for prompt customer service.
What do I think could be better?
1. The included battery has fairly short cables which can make it a challenge depending upon where you place the battery relative to the camera and monitor. OCT tells me they have a new battery with a longer power cable.
2. For some, the video cable is shorter than they would like. OCT sells a 25ft power/video cable for $12.99. When I mount everything on top of my SCT, the video cable is actually a bit longer than I need.
3. The LCD monitor is not a high end monitor, so you may want to upgrade to a nicer and larger monitor. You can use your existing television so long as it has a composite video input, which most still do.
Is the R2 worthwhile? Absolutely! It is a very well thought out and assembled package. Like I said above, it has everything you need to add to your existing telescope to get started viewing the very first night. Can you buy better accessories than the ones supplied in the package? Certainly, and many prefer to go the route of sourcing the individual components themselves to save some money or to upgrade to better components. But this requires a bit more knowledge of what to buy and how to put it all together. And you will have to purchase many of these components on-line from multiple sellers. OCT has taken all of the hassle and uncertainty out of the process. And their web site has detailed instructions on how to assemble everything, a FAQ section, a guide to the camera menu and suggested starting settings for planetary and DSO objects. In addition, Mike Fowler at OCT has a good reputation for providing telephone support to help get you started.