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Orion SkyView Pro GEM and Intelliscope DSC

Posted by John MacDonough   04/08/2008 12:00AM

Orion SkyView Pro GEM and Intelliscope DSC
Orion SkyView Pro and IntelliScope Review


I know bunches of you skip to the bottom and read the conclusion, so if you’re one of those folks, I’ll save you some effort: this is a positive review. The scope of this review includes Orion’s SkyView Pro (SVP) mount and IntelliScope computerized object locator, which is a fancy way of saying digital setting circles (DSC). For those that don’t know, DSCs use encoders to help a computer keep track of how much the telescope has been rotated about its axes. Once the computer has been given a reference point (or more than one) it can keep track of where the telescope is pointed and direct you so that you point the telescope where you want.

I’ll briefly discuss my experience with installing and calibrating the encoders. Finally, I’ll discuss some of the features of the IntelliScope computer itself.


The SVP is my secondary mount; I use it for “grab-and-go” observing at my house. I use either a 66mm William Optics refractor, or a 102mm Orion Maksutov-Cassegrain telescope on this mount. I do not have a polar scope or drive motors on the SVP. The encoders preclude the use of a polar scope. I wish Orion could figure out a way to install both, I miss the polar scope.

I have owned three other mounts in my short observing career. My main mount is a Losmandy G-11 with Gemini go to. My 102mm Mak came with the Orion EQ-2, which I sold after purchasing the SVP. I’ve also owned a Meade DS-2000, their entry-level single arm mount. I’ve seen three other examples of this mount in action and only one of the four owners could get it to behave. That owner was not me, so I sold the DS-2000 as well.


I purchased the SVP for quick set-up applications. That mission is accomplished. The whole rig: telescope, mount, tripod and counter weights, only weighs thirty pounds so I can carry it outside already assembled and be ready to observe in two minutes (twelve if I want to initialize the IntelliScope). If the gear has been stowed, I can have all the bits outside and assembled in ten minutes (so that makes for twenty minute set-up if I’m using the Intelliscope that night). Take-down is just as easy. I often just bring the assembled rig inside and take it apart in the morning.

Let’s start at the bottom with the tripod. The rubber feet give some measure of vibration damping, and they don’t make an obnoxious grating sound if they are scraped across concrete. The steel legs are quite rigid when supporting my small scopes. The legs can be made very long; but I haven’t measured the actual maximum height. The locks for the leg extensions lock securely, although I wish someone could figure out how to put the locks at the tops of the legs.

The spreader plate doubles as an accessory tray. I can’t comment on its effectiveness as a spreader, I’ve never not used it, but having an accessory tray is a luxury. My G-11 does not have an accessory tray. If I’m only going out for an hour or two with my small scopes, being able to have my favorite five eyepieces right at hand is a welcome feature.

The axis locks for the mount itself operate the same way as the tripod leg locks and are just as secure. The Vixen-style (or CG-style) dove tail bar is such a HUGE improvement over the ¼”-20 single post mount of the EQ-2 that I won’t comment further. The slow motion controls work as they are supposed to (how could they not?), but I wish Orion supplied at least one cable. The SVP comes with two knobs for the slow motion controls. I used both knobs on the RA axis, and added a cable for the Declination axis. The gears are a bit rough and the grease is pretty stiff; so stiff that I don’t think critical balance can be achieved. There are several websites that both recommend and give instructions for polishing the gears and applying new grease to improve the smoothness of the mount. Astrophotographers will no doubt want to investigate “how to”. Problems with grease seem to be a recurring theme with mounts. Why do manufacturers choose the grease they do?


I bought my IntelliScope unit as the upgrade kit for my SVP, so I had to install it myself. This is the only installation I’ve done and I’m pretty happy with the results, so I can’t comment on mistakes I’ve made or “gotchas” to watch out for. I won’t say the procedure is fool-proof, but I did it, so I bet you can, too. My advice for installation and set-up in general is be as accurate as you can since you only have to do it once. I read the instructions three times before I started. It only took thirty minutes total and it helped me remember what was coming next in the installation sequence. I followed each step, even if it seemed weird at the time. I think it took me two hours to install the encoders, but I was watching football and babysitting the kids at the time, so the project didn’t have my full attention.

Once the encoders are installed you’re required to set the 0 degree declination reference mark. For me, this took about an hour-and-a-half, but I had to load the gear, drive a couple of minutes to an open field, set-up and then reverse the process when I’d finished. I think I spent forty minutes working on the reference mark itself. Orion says the goal in setting the reference mark is to get the telescope aligned on the mount and the mount aligned such that when you flip the telescope 180 degrees in RA your target stays centered in the eyepiece. I never did get it to stay centered, but I came kind of close. As I’ll discuss later, pointing accuracy is fine for my purposes, so I must have done an acceptable job for my own uses.

My routine when I set up to observe includes: an “eye ball” polar alignment, leveling the tripod, moving the counter weight shaft so it’s pointing down, aligning the mount with the 0 degrees Declination mark and starting the computer. When centering the alignment stars to build the pointing model, I use a 10mm double cross hair reticle eyepiece. In my experience this is crucial for accurate pointing. Centering by eye, even with high magnification, just didn’t get the pointing accuracy I like to have. I’m grateful for my reticle eyepiece.

I start with the minimum two star alignment. I use alignment stars in, or near, the constellations in which I’ll begin my observations. When I’m ready to move on to a different part of the sky, I’ll pick another alignment star close to my new “neighborhood” and add that star to the pointing model as an additional alignment star. This is similar, for those familiar with AutoStar, to the “high precision pointing” feature.

Here are the interesting (to me at least) results of a couple of experiments. I almost always use the slow motion controls to move the scope, mostly because I’ve heard stories that encoders can “lose their place” if you move a telescope too fast when slewing. I did try loosening the locks and moving the telescope by hand. The encoders kept up and pointing accuracy was still good even though I’d moved nearly 180 degrees in both RA and Declination. Once, I also set up with polar alignment off by 45 degrees, leaving all other set-up aspects the same. I built the pointing model and was amazed to find pointing accuracy to be good. Tracking was terrible, of course.

The IntelliScope computer is a good companion under the stars. Let me start out with what I don’t like and finish with the good stuff. First off, the guide arrows on the display that tell you which direction to push the scope are a bit off in my opinion. The RA arrow pointing right means to move the scope west. Seems like the arrow should be reversed: I consider west to be left (northern hemisphere, you know). The Declination guide arrows point up for north and down for south which seems reasonable to me. The monthly tours are a bit short and seem geared for 6” and larger scopes. I wish Orion would include more objects, and more for small scopes (the tours in my friend’s NexStar computer are great). The information available for each object is quite abbreviated. For example, double stars get the magnitude of the primary, separation, and sometimes a short note about colors or relative magnitudes. I’d like to see magnitudes of both stars, separation, position angle and perhaps notes about colors. I wish the controller gave a beep before automatically shutting off. Also, the information text scrolls quickly enough that the display is hard to read. I’ve gotten better at it with practice, but I think the scrolling should be slowed down. One last nit to pick: I wish Orion would supply a piece of Velcro for each tripod leg.

The “warp factor” is a measure of the offset between the position of a celestial object in the database and that calculated by the model (I think other programmers use this term also, but it’s new to me). Orion says the goal is to have the warp factor –0.7 > wf > 0.7. Using a reticle eyepiece during alignment, I regularly achieve 0.3 or less. However, I have seen it skyrocket to 1.7 after a meridian flip, but pointing accuracy didn’t seem to suffer, so I don’t know how important it really is.

The controller box is a good size for my hands. The buttons are big enough to be used with light gloves; although, I bet you folks in snow country would have difficulty in the winter with ski gloves on. I really like that RA/ Dec coordinates can be displayed in real time. It makes the controller “universal” in that if you have an object’s coordinates, you can find it (you aren’t limited to the objects in the database). The Galaxy, Nebula, and Cluster buttons activate lists of those types of objects that are grouped by constellation. The double star selection is fairly broad.

Sorry to make you wait until the end for what you really want to know. Pointing accuracy is pretty good. I’ve used two different scopes with this mount: a 400mm f/l refractor and a 1,300mm f/l Mak. With my eyepiece collection the refractor’s AFOV is between 0.625 and 4 degrees; the Mak’s AFOV range is between 0.19 and 1.5 degrees. I’m going to sing the praises of the reticle eyepiece again because I think using one is critical with this system, but the IntelliScope system puts objects in the wide fields of view every time when I exercise care in building the pointing model. In fact, I observed Saturn in late March with the Mak. I slewed to Mars for a brief, uninspired look and slewed back to Saturn. Saturn was so close to the field of view when I slewed back the planet’s glare, but not the disc, was in the field. I didn’t even use the finder to bring it into view. I was using my 7mm ortho, AFOV 0.27 degrees (16’, about ½ the diameter of the full moon). That’s pretty good as far as I’m concerned.

Orion does have a short section in the owner’s manual about optical axis alignment. I’m sure I could improve pointing accuracy further by following those steps as well.

In conclusion, I really like the SkyView Pro mount and the IntelliScope system. In their catalogs, Orion seems to be pushing the IntelliScope for their Dobs, and the go-to for their GEMs. I think that’s a shame. The IntelliScope is a good upgrade and they should be proud of the product. The nits I picked: stiff grease, rough gears (probably important to imagers only), short tours, abbreviated object information, information scroll speed. The positives: light and stable, really quick to set up, compact, surprisingly accurate pointing, the system is easy to learn and to use and the encoders seem robust.

Some time in the future, I plan to make the following modifications/ additions and I hope to remember to report on them.

1: Clean and regrease
2: RA motor