The Celestron fork mounted Schmidt Cassegrain telescopes changed the world of amateur astronomy with serious aperture in an all-in-one package starting with the C8 in 1970. As time has moved on, these have become increasingly sophisticated. There's just one catch: the Fork and the Optical Tube Assembly (OTA) can't separate from each other. So it's a mono-tasking mount locked to the scope. In the case of a C11, that's a 65 lb package called a CPC 1100. But there's another way: German Equatorial Mounts (GEMs), which will carry the telescope separately. At that point, you have to unbolt the telescope from the forks, and then it weighs only 27 lbs. Oh, and you need the subject of this review: a dovetail plate.
I debated getting an 11" telescope for quite some time before I took the plunge. There's not just the size of the things- they are committed to smaller fields of view. But as I became more serious about astrophotography, the adavantages of using hyperstar imaging, where a C11 has a camera attached to the front end and is used at f/2, were overwhelming. So, I moved to the fork mounted version, attracted by overall compactness and the trick it does where it will track objects all night long without having to do special maneuvers the way GEMs do. But there turned out to be a very large price to pay- putting the telescope onto a wedge is flat out scary, and even doing it a few dozen times makes it no less so.
The reason assembling the mount onto a wedge at an angle equal to your latitude is a problem is the telescope and mount combined package is really, really, heavy. 65 lbs of large and awkward delicate equipment is nothing to sneeze at. Holding it at an angle of 32 degrees from vertical to get it bolted to a wedge isn't trivial. And I had to face the elephant in the room- the mount was not as stable as GEMs, and that was why a third to half the photos I took were getting blurred by shaking.
In the meantime, German Equatorial Mounts, which got the name from the German telescope making pioneer Joseph von Fraunhofer who invented it over 150 years ago, have become quite modern. For starters, they are available in many sizes, have computer guidance, are really well made, and are now easy to connect to thanks to the development of dovetails in two sizes:
Vixen pattern dovetails, used with small to mid sized telescopes up to ~20 lbs.
Losmandy pattern dovetails, which are used for telescopes in the range of 15-70 lbs.
The C11 can be used with either, though the mounts it is most easily at home on, and clearly will work better for astrophotography all use Losmandy type dovetail plates.
Description and Usage
The Celestron 11" dovetail bar comes packaged in a box with bubble wrap, which is a little amusing when you get the dovetail plate unwrapped and discover it is about as dainty as a crowbar. I am not knocking them for this, though- it's nice to have it arrive without scars from being banged around. It comes with the screws and hardware needed to attach to various generations of C11, and I actually don't know of a generation of C11 (going back to the early 1970s) it won't attach to.
But the most impressive thing about it is the color. It is anodized orange. And I do mean ORANGE, glowing, bright, walk outside and shout, ORANGE. I'm generally not a fan of that color, but the brilliant tangerine hue of this part really stands out.
Attaching it to the telescope is quite easy. The bottom of a fork mounted Celestron C11 has all of the holes drilled and tapped for the dovetail bar to bolt right on with the included screws. There are screws in the existing holes to prevent contamination. Once the dovetail bar is on, it's time to free the telescope from the mount.
Now, the mount gives the impression the telescope can just be unbolted from the two trunions attaching it to the fork arms, but in reality there are two concealed pins which register the telescope in place, and mean one arm has to move to get the telescope free.
First, put the telescope somewhere it can come apart without getting damaged. The middle of a bed is ideal.
The arm to loosen is the one without the drive, which is the one without the clutch, or the right side. This side has a simple bearing and allows for a little float in the telescope's position. To loosen the arm, the plastic cover has to come off. At the bottom there are four large phillips screws next to the drive base. Loosen these screws. Now, take out all of the screws holding the telescope to the two trunions on either side. The telescope won't come apart yet- you need to gently pull on the right hand fork arm. The telescope alignment pin is close toleranced, so you may need to use something made of wood (so you don't marr the finish) to gently pry the two parts apart. Do the same on the drive motor side as soon as you get the right hand arm off. You may need to pull the pins out of the telescope housing with pliers. You do NOT want to risk them getting forced inside where they can run into the primary mirror. Voila, your telescope is free!
You will likely be shocked at how light the optical tube is compared to its size. And in that vein, the entire exercies of having it on the fork mount may seem a little silly. What the forks really could benefit from is some easy way for telescopes to go on and off them. You will also notice how surprisingly heavy the forks are without the telescope on them.
You will need a German Equatorial Mount to put it on. Anything with 45 lb. capacity will easily hold this telescope with cameras or other accessories attached. One exmple is a Celestron CGEM, which handles it quite well.
The Celestron Dovetail Bar is somewhat different from an official Losmandy D series dovetail in several regards:
(1) The angled part is longer. This makes it easier to get a telescope into the dovetail clamp on the mount, but may change how it goes in compared to other dovetails.
(2) It is slightly narrower. So, if you are switching between the C11 with this dovetail and something with a regular Losmandy dovetail, open the clamp on the mount further than it takes to just let go of the dovetail bar.
(3) There is no provision for safety screws. It is common to have a threaded hole somewhere at the end of dovetail bars so if the dovetail clamp is inadvertently loosened with the telescope in it, it can slide out and land on the ground. This is the single largest omission on this product. In my case, I drilled and tapped in a pair of holes in the ends of the tines so I could put in my own stopping screws.
Use on GEM mounts makes the C11 much easier to move around, and has resulted in it getting out under the stars more often. Since this is what the goal was all along, that's a good thing.
The Celestron C11 dovetail bar really frees that telescope from the encumberance of a fork mount. The only real problem with this product is the lack of safety screws at the ends of the tines. All I need to do now is figure out a use for a perfectly usable fork mount perfectly adapted to only one telescope.
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