The observatory and equipment

 The first thing we bought a few years ago to start observing the stars was a 10" dobsonian. It has since undergone a few modifications and continues to be a nice scope when the visual observing bug hits. There was one other scope that I owned years ago but it isn't really worth mentioning here. My wife Cara wrote a rather entertaining story of that telescope on her blog and can be found here.

 The 10" dob really does put up some fantastic views since replacing the secondary mirror with a premium 2.60" 1/20 wave (peak to valley) unit from Antares Optics. I also replaced the stock straight 4 vane spider holding the secondary mirror with a curved 3 vane spider from Destiny and installed Protostar flockboard to the interior of the telescope tube.  That greatly improved the contrast. While this is still a pretty nice scope for observing, the human eye just cannot see what a camera sensor can capture with a short exposure of just a couple minutes. Enter astrophotography....

 After buying a Canon T3 DSLR and trying it on our dobsonian telescope we quickly realized that just wasn't going to work for anything other than some shots of the Moon. I did some research and decided to get a Celestron CGEM DX german equatorial mount and the Astro Tech AT8IN 8" imaging newtonian to get us started. The fast (f/4) optics of the telescope worked great to reveal excellent detail in objects that we just simply could not come close to seeing through an eyepiece. We were not serious into astrophotography then and just used single 2 minute exposures to explore the night skies. It was quite a treat to explore the universe from our backyard. This scope has continued to serve me well after upgrading the weak focuser with a very nice unit from Moonlite. These focusers are extremely nice and I would like to someday have one on all my telescopes.

 The 800mm focal length of the AT8IN worked fine for most objects but there are several things in the night sky that are much too big to fit even on a sensor as big as the one in our DSLR. I started looking into a wide field scope and settled on the Astro Tech AT65EDQ. These little astrographs come with a built-in field flattener and are excellent for wide field astrophotography. I cannot say enough about this little scope and use it exclusively for all my wide field work. With a focal length of 420mm it provides roughly twice the field of view that I get with my imaging newtonian. With the Canon T3 it will show a field of 3 degrees wide X 2 degrees high. When you consider the full Moon takes up roughly 1/2 degree of sky you can see that this scope will show you a pretty big area.

 Around this same time I was able to get a couple of nice used Schmidt Cassegrain telescopes for some long focal length observing and I thought eventually I could use them for astrophotography. The local university here had a 10" Meade LX50 and an 8" Celestron Celestar and the price was such that I couldn't refuse. These are both f/10 telescopes with focal lengths of 2500mm and 2000mm. I picked up a Celestron focal reducer/field flattener that reduces the focal ratio of both these scopes to f/6.3 which is much more conducive to astrophotography. The focal lengths then become 1575mm and 1260mm along with better looking stars in the corners of the field. I de-forked the Meade and purchased a dovetail to use it on my CGEM DX mount and eventually did the same with the C8.

 The CGEM DX mount is extremely heavy and takes several trips to get set up. I decided to get a lightweight mount that would work well for observing with the bigger scopes and would serve as a nice imaging platform for the lightweight AT65EDQ. I bought the Celestron CG5 mount that has a capacity of 30 lbs compared to the 50 lb weight limit of the CGEM DX. It works great and is so light that I can just pick it up completely assembled and carry it out in one trip (minus the counterweight and battery).
 Wanting then to get more serious into astrophotography I also purchased an autoguider system from Orion Telescopes and Binoculars. This allowed for much longer exposure times and nice round stars instead of egg shaped stars. Since buying the autoguider the hobby of astro imaging has really taken off. Here is a picture of the CG5 mount with the AT65EDQ and the Orion ST80 80mm f/5 guidescope mounted piggyback. I have since replaced the ST80 with a much smaller and lighter 50mm finder/guider that has been working great on all my imaging scopes.

 The small apo was great for learning astrophotography. The short 420mm focal length is much more forgiving to guiding errors and really helped us get started with long exposures. Many people will get frustrated and give it up when they start out with a scope with more focal length than this so I think it is ideal for any beginner.
 Once we thought we had perfected the shorter focal length I put the AT8IN on and started getting some long exposures at 800mm. The higher resolution showed us even more detail and I was anxious to try a scope with even more focal length to see the fine details on the smaller targets in the night sky. I put the Celestron reducer/flattener on the C8 to give it a try. Some people out there have good success imaging with the Schmidt Cassegrain telescope but I quickly decided this was not for me. The design of these scopes incorporate a primary mirror that slides on a baffle tube toward and away from the secondary mirror to reach focus. This causes focus shift which makes it tough to center your target. You get mirror flop when the scopes slews from one side of meridian to the other. These scopes are completely enclosed with a corrector plate on the front and take hours to reach thermal equilibrium. They also have terrible field curvature even when using the field flattener. For imaging at least, these scope are not for me and have been relegated to visual use only.

Still needing a telescope for long focal length work I began eyeing the Ritchey-Chretien (RC) astrographs. I had a few questions about them and began exchanging emails with Levenhuk Telescopes about their 8" RC with the carbon fiber tube. The saleswoman responded quickly to my questions and offered the scope to me for $160 off the website price. I told her I wasnt really ready to buy one yet and was just looking and had a couple questions. It wasnt but a few minutes later when she responded by saying she could let me have one for $300 off. Well, I'm a sucker for a good deal and I am now the proud owner of a Levenhuk 8" RC with a beautiful carbon fiber tube.

Buyers remorse sometimes sets in after purchasing something you were only looking at but I have no regrets at all. With this scope I have imaged over multiple nights and not even had to touch the focuser. The carbon fiber tube is not just for good looks. Carbon fiber is the super-hero of the materials world. It is one of the strongest and most lightweight materials on the market today. It is five times stronger than steel and one-third its weight. Carbon fiber will expand or contract much less in hot or cold conditions than materials like steel and aluminum. This makes it an excellent choice for a telescope that will be used and stored in a wide range of temperatures.

The optics of the RC have a focal ratio of f/8 which was much different than what I was used to. I discovered to get the same amount of light to the camera sensor that I was getting in 5 minutes with the f/4 scope, that I would have to start using 20 minute exposures at f/8. The challenge of twice the focal length combined with four times the exposure time was not something I was ready for just yet. To remedy this I found a used Astro Physics CCDT67 Telecompressor. The spacing between the reducer and the camera sensor determines the amount of reduction. With the 2"/T2 adapter I have the reduction comes out to be .71X and brings the focal ratio from f/8 down to a more manageable f/5.68 and drops the focal length from 1600mm to 1136mm. This is still quite a bit more than the 800mm focal length of the AT8IN and this combo has been working out great for me. They are together the second best thing to date that I have bought for my astrophotography hobby.

 
The best thing would be, without a doubt, the roll-off roof observatory. How many of us have spoken some not-so-kind words of our local weatherperson? Born and raised here in Arkansas I have often heard said to visitors, "If you don't like the weather, stick around a day or two. It will change." Other than the Summer months, I'd have to agree. The CGEM DX mount weighs over 100 lbs and its just not something I wanted to get set up and aligned unless the weather was sure to be good. There's been several nights since I've been into amateur astronomy that the weatherman had forecast clouds only to peek outside to find it clear. There's been several nights I couldnt sleep that I would look out to see a sky full of beautiful stars. Besides the trouble of setting things up (and then tearing it all back down!), there's this thing called tube currents. Most of my scopes take at least an hour to acclimate to the outdoor temperature.
 The observatory has been the answer to all these problems. I can now go out anytime I feel like it and roll the roof open and immediately start imaging or observing. I would encourage anyone that is seriously into this hobby to build something similar. When I was researching observatories I found many that were MUCH nicer than the one we built. I also found a few that were not much more than an outhouse on wheels that just kept the scope covered and out of the weather when not in use. There's certainly nothing wrong with those and I considered that, but I wanted something that would keep a few other things stored. The style I saw more than any other was the Arrow (or similar) storage shed converted to a roll-off roof. I bought the Arrow 10 ft X 10 ft storage shed for only $300. Its not completely finished yet but for less than $1000 total I was using it on an almost nightly basis. On just about about any clear evening now you will find me out in my humble observatory with my Canon DSLR camera soaking up some photons.

   So there it is. This is the equipment I am working with. If you have read this far then you are either really interested in astronomy/astrophotography, or you are kin to me. Either way, check back here at LPO from time to time to see whats happening. :)