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Orion Astroview 120 ST

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Date: 1-13-2003
Price: $429.99
Design: Traditional refractor featuring a short f/5 optical system with a 120mm lens
Description: Medium sized refractor that comes equipped with an  equatorial mount, 6x30mm finder, and a pair of 10mm and 20mm Plossl eyepieces.

Observing history and geographic location

I’ve been an avid amateur astronomer for about ten years, with my main focus of study being the moon, the planets and DSO’s. I’ve had a variety of scopes from a wide range of binoculars and reflectors and I now have an 8” SCT. I’m more of a general interest observer. If I am short on time I’ll just check out the moon if its out or the planets at that time. Perhaps a few of my favorite DSO’s like M42 or M31. If I do have more time, I’ll go through the Messier list as much as I can or I’ll take more time with the moon and planets.

It should be noted that I live in north central Wisconsin. The upper Midwest is known for poor seeing conditions most of the time, though we do occasionally get some excellent nights. All observations made thus far were early in the night where all objects were close to the horizon and the seeing conditions were rather poor (perhaps a 3 or 4 on a scale of 1 to 10). Not a particularly prime observing environment. I am used to conditions like this, so its all that more important that I observe with the best I can get for my money.

Reasons for choosing the Astroview 120ST

As much as I love my Meade 8” LX50, I can’t use it as much anymore as I have less time now with three kids and 2 jobs in addition to having a bad back. Those factors led me to finding a low cost, easily portable scope that I could take out at a moments notice with little or no setup time.

My options were limited to price, size/weight, ease of setup and versatility. Since I still have my SCT (that at some point will go into a small permanent observatory) getting a smaller SCT was not what I was after. Nor did I want to go the route of a reflector. I started looking into short tube, rich field refractors. The APO’s looked great but way too pricey. I looked at other low cost alternatives…but most of the achromats of any kind all had the chromatic aberration caveat. Together with a ton of reviews and a few good recommendations from some fellow stargazers, I purchased an Astroview 120ST from Orion Telescopes, www.telescope.com. I had some reservations about this purchase as most complained of terrible high power views. I expected that (as well they should have) for this short focal length achromat. But Orion has a great customer service department, so I was not concerned if this was not quite up to my expectations.

The Astroview 120ST is a 600mm, f/5 short tube refractor, with a 4.7”, multi-coated objective lens that is meant for wide field viewing, not planetary or moon detail. Orion clearly states its use as such. But from my first times out, I have been able to really push the magnification on the moon, Jupiter and Saturn, revealing an extreme amount of detail for this type of scope.  It is lightweight at only 9 lbs and only 24 1/2” long so it its size is perfect for me. I can leave it on the mount and carry the whole thing out side and start observing immediately, which is important because I have such limited time and sometimes I can’t haul out my SCT. Also because of its size, I can now take it with me wherever I go as the whole setup fits easily into any size vehicle.

Equipment and shipping

I received my scope from Orion in 5 days with standard ground shipping. It all came in one box, with most every component packaged in separate boxes within. The scope itself was only wrapped with tissue paper, with bubble wrap around that. I would have expected some kind of fitted foam for the scope at least. But everything was in perfect shape.

The Astroview 120ST is sold as an OTA only or a package. I purchased the package for $429 (shipped) and it comes with everything you need to start viewing, which includes a 2” focuser (for optional 2” accessories), a 1.25” diagonal,  1.25” - 10mm and 25mm Plossl EP’s, 6 X 30 finderscope with bracket, , tight fitting endcaps, 2 counterweights (about 10 lbs. total), mounting rings and the Astroview (EQ3?) mount and aluminum tripod...with a nice accessory tray and a hinged leg stabilizer (which is nice for quick setup and tear down as the legs fold up quickly without having to remove anything).

When I first looked at the scope, I was happily surprised at the solid feel of its construction. The tube finish was a shiny black with the focuser and lens cell assembly made of cast aluminum that is painted with a black textured paint (rather than the black anodized finish of more expensive APO’s). It felt heavier than I thought 9 lbs. would. I guess at $429 with a mount, I was expecting a more cheaply made scope, but it is very well made. I also expected a flimsy, rattling mount. I had owned a few cheaply made EQ mounts in the past and I thought at this price, the mount would be similar to those. But I was quite pleased with what is a very solid, beefy mount for this size. More about the mount later. My first impression of the scope and mount was that it was substantially better than I imagined.

Performance

My first few nights out with the Astroview 120ST, I could make out Cassini’s division in Saturn and at least 4 cloud bands on Jupiter as well as gorgeous details on the moon. I’ve read other’s comments about this scope’s inability to resolve much detail and that the views “mush out” at anything above 60-80X magnification (which one would expect from an achromatic refractor of this length), yet I pushed it to 120X with a 10mm EP and a Barlow and it still maintained very sharp images. The views seemed no different with my Meade 26mm & 10mm Super Plossls than with the supplied Orion 25mm & 10mm Sirius Plossls. The Barlow is Orion’s 2X APO shorty.

On star tests, there is a bit of flaring, both in and out of focus, but only at the edge of field. Stars when in focus are perfectly round points of light. The field of view is very wide indeed. With the supplied 25mm EP, this scope engulfs all three stars of Orion’s belt in the same FOV. Even the Great Orion Nebula was still quite sharp at 120X and very bright and clean, with the 4 stars of the trapezium clearly defined. Chromatic aberration is minimal. It is vaguely noticeable on very bright objects such as the moon and planets…with a hint of either purple or yellow (only at the very fringe on one side of the object, or the other, depending on how you move about the EP). There is no other discernable coloration of objects…no purple or blue tones with anything. Aside from the fringe color, I get the same colors as my SCT.

In comparison to my Meade 8” LX50 SCT the Astroview has sharper optics and more contrast. My SCT has perfect collimation and beautiful views…and of course a larger aperture so it should resolve more detail, but in side by side comparisons the Astroview’s optics reveal crisper and more defined views at about the same magnification. I’m sure at higher magnifications my SCT will remain sharper, whereas the Astroview’s short focal length will start degrading the view, though I have not had a chance to test it at higher than 120X. Others who own the Astroview 120ST report to me that on nights of good seeing that they have been able to push the magnification up to 240X and still maintain crisp views, but I have no way of authenticating it.

The 2” focuser has a 1.25” adapter. The focuser is solid and smooth. Achieving focus is a snap and the focuser holds the focus, even without the lock down screw tightened. Focus is very easy to obtain and sharpen and much easier than similar focusers I’ve had on reflectors.

The supplied 6 X 30 finderscope is all metal except for the small dew shield. Orion got rave reviews from Sky & Telescope for their design of the finder bracket’s alignment. It is so easy to align with only two set screws that push the finder against a spring loaded pin. At first I thought a 6 X 30 finderscope was a bit cheap as I am used to the more robust 8 X 50’s, but in reality anything over 6 X 30 is overkill. The Astroview has such a wide field of view that one could almost star hop through the scope itself. I think a red-dot finder would be most appropriate for this wide field scope. The only complaint I have about the finderscope bracket is the manner in which it is attached to the scope housing. The dovetail seems to be pointing in the wrong direction, because if you are viewing overhead and the set screw loosens, it will slide right out onto the ground!

The mount is called an Astroview, but it looks just like Orion’s EQ3 mount…which I think is either a CG-4 or CG-5 knock-off. It is very solid and robust. It moves smoothly, though it is a little stiff, but there is no sticking anywhere. It may just need adjusting or like the CG mounts, it needs to be taken apart and cleaned and regreased. For tracking or astrophotography I will use my SCT and I may even add a mounting bracket to my SCT’s OTA to mount the Astroview to it as a guidescope, viewer or wide filed photography platform while on my SCT. Unless the Astroview mount is adjusted and/or cleaned and regreased, I wouldn’t add a drive to it as it is a little stiff, though smooth in operation.

The mount’s setting circles are so loose (with a lot of play in them), that one could not really use them for exact location of objects. They seem quite sloppy, cheap and almost an afterthought. The polar alignment scope that comes supplied with it, according to the directions, is way too time consuming to bother with, given that one really wouldn’t want to use this mount as a platform for astrophotography anyway. I use it more like a more controlled Alt-Az mount since I use the scope more for quick and easy viewing anyway. The flexible RA and Dec movement cables work quite nicely for keeping objects in the FOV. The mount gives you the option of placing them on either side of the mount for easy access. One thing to keep in mind with this mount is that the mounting rings bolt directly to the mount. There is no dovetail/saddle assembly for this mount, although a person could make one easily

The aluminum tripod legs are not very stable when full extended (as one would expect), but very solid when fully retracted and overhead views are not really hindered as this is a short tube…not the monolithic  4 foot long focal length refractor. The height of the mount (at its base) when the legs are fully extended is 47” and when fully retracted is 26”. I found a happy medium in height versus stability. If the legs are about halfway extended (which allows for fairly comfortable viewing while standing) the damping time is around three seconds…which, even at 120X is no bother…and focusing alone does not make it jitter much, if any. Only bumping into the scope or tripod makes it jiggle, so overall it is quite stable. This is the exact same mount that Sky and telescope reviewed with the Orion StarMax 127 EQ (Mak) in their March 2002 issue.

Conclusion

Overall, I think this scope is greatly underrated for what is capable of. It is not an APO to be sure, but because of the way it performs, it certainly acts more like one than your typical achromat, much less a short tube at that! Still, the mount leaves a lot to be desired for astrophotography, but at the price of this setup one can hardly complain. 

PROS:

Stunning wide field views, even at higher than recommended powers

Incredibly low price

Mount and scope have a very solid construction and feel.

Smooth operations of focuser and mount RA/DEC axes

Fast aligning finderscope

Tight fitting endcaps with lens endcap having a removable “stop-down” cap

Hinged tripod leg stabilizer

2” focuser to accept any 2” accessories

No false color on objects with a hint of fringe color on bright objects only

CONS:

Very slight chromatic aberration (this should really be a PRO as this scope is not an APO)

Cheaper finish on cast aluminum focuser and lens cell assemblies

Plastic focus knobs and tripod leg adjusters

Loose, sloppy RA and DEC setting circles

Aluminum tripod legs (not unique to this mount)

No dovetail/saddle assembly for mount

Finderscope mount attachment to scope is precarious

Polar alignment scope endcap falls off easily

Submitted by Anonymous

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