Orion ST80 & Stellarvue Nighthawk

Orion ST80 and Stellarvue Nighthawk
80mm Refractors for Beginner or Expert


Let's take a look at two telescopes that can be a great first telescope for the beginning astronomer, or the perfect "grab and go" telescope for the seasoned veteran. Both the Orion ST80 and the Stellarvue Nighthawk fit this description. Both of these telescopes are 80mm short focal length refractors. They share the inherent advantages of this design, as well as it's one major drawback. These telescopes represent what you can expect at both ends of the cost range for a short tube 80 mm achromat.

First, a bit of information about this design: The two big advantages this design has over most other types of telescopes are portability and wide field of view. There are other advantages to this design, but these are the two that stand out. Portability needs no further explanation other than to refer you to the lengths and weights in the table below. Compare these numbers to other designs and you won't need any more convincing. Wide field of view merits a bit more explanation. Due to the short (400mm to 480 mm) focal length of this design, the magnification with any given eyepiece tends to be lower than with other telescopes. This means is that you see a much wider section of sky than most other telescopes will give you. This is a big aid to the beginner looking for objects in the sky, and contrary to what you may be thinking, you won't find yourself short of useful magnifying power. Now for the disadvantage, 80mm (approx 3 inches) is not a lot of aperture, and this will limit the amount of detail you can see with this type of telescope. This can not be avoided, regardless of how good the optics are, aperture size will be a limiting factor.

While we are on the topic of optics, a word about achromatic versus apochromatic is in order. Both the Orion ST80 and the Stellarvue Nighthawk are achromats, which means that they are subject to chromatic aberration. This means all the wavelengths of visible light are not focused perfectly to a point. There are other telescopes on the market similar in design that are apochromatic, and they do a better job of focusing all the light to a point. The problem is the apochromatic designs are easily triple the cost of achromats. Whether the extra cost is worthwhile is a topic for another day. However, you can be sure that the less expensive achromat will give you a lot of bang for your buck. With this background in mind, let's look at the features of these two telescopes.

The Orion ST80 and the Stellarvue Nighthawk are similar, but with some important differences. The Orion ST80 is the less expensive of the two telescopes, and is Chinese made. The Orion ST80 is mass produced, and virtually identical models have, and continue to be sold under different names by other manufacturers. The Stellarvue Nighthawk is the more expensive of the two telescopes, and it is assembled in the U.S. with some of the component parts made off shore, presumably in China. The Stellarvue Nighthawk is decidedly not mass produced as the optics are hand fitted.




Orion ST80 on Mount

Cutting right to the chase, when all was said and done, I felt the optical performance of the Orion ST80 was very close to the Stellarvue Nighthawk. I chose the Orion ST80, over the Stellarvue Nighthawk, and spent the money I saved on an 8" dob. You may judge by different criteria than I did, so lets look at the differences between these two scopes so you can decide what fits your needs. First the numbers:

	Orion ST80	Stellavue Nighthawk
Design	Achromatic refractor	Achromatic refractor.
Objective Lens	Fully coated	Fully multi-coated hand fitted and checked
Objective size	80 mm	80mm
Focal Length	400 mm	480 mm
Weight	3.8 lbs	6.5 lbs
Length	15.5"	16.5"
Mounting	(1) fixed 1/4-20 hole	(3) 1/4-20 holes in adjustable tube ring
Focuser	1 1/4" rack and pinion	2" rack and pinion w/oversize knobs, (Crayford focuser available)
Lens cap	Plastic, snap on	Aluminum, thread on
Dew shield	Fixed	Sliding
Light grasp	7.8 in	7.8 in
f/ratio	f/5.0	f/6.0
Cost*	$179/$225	$349/$449
Included accessories*	10mm and 26 mm eyepieces, 1 ?" 45 degree diagonal, 6x26 finder	Red dot reflex sight
Finder*	6x26 correct image	Oversize red dot reflex
Country of Origin	China	U.S. final assembly, Optical elements made offshore.
* I have given two prices for comparison. The first price is for the optical tube assembly. The Orion ST80 optical tube is packaged with two eyepieces, 45 degree diagonal and 6x26 viewfinder. The Stellarvue Nighthawk optical tube assembly includes only a red dot finder. The second price represents both scopes outfitted with similar quality eyepieces, 90 degree diagonal, and similar red dot finders.

It may not be jumping out at you when you look at the numbers, but when you have these two scopes side by side, one of the first things you notice is how much heavier the Stellarvue Nighthawk is compared to the Orion ST80. The construction of the Stellarvue Nighthawk is heavy duty and the weight is the first indication of this. Telescopes are not intended to be dropped, but if there is a telescope that could be dropped and still work, the Stellarvue Nighthawk is it. Everything on the Stellarvue Nighthawk it is overbuilt. On the Stellarvue Nighthawk, the dew shield is thick aluminum, probably about 3/16" thick, about twice as thick as the same part on the Orion ST80. The Stellarvue Nighthawk mounting holes are in a heavy duty cast aluminum ring which can be adjusted and moved to balance the scope on the mount. On the Orion ST80, the mounting hole is in a small aluminum plate that is fixed to the tube. The Stellarvue Nighthawk has nice easy to grip rubber oversize focuser knobs, where the Orion ST80 has smaller plastic knobs. The snap on plastic lens cover of the Orion ST80 is fine, but it does not really compare to the solid aluminum thread on lens cover of the Stellarvue Nighthawk. This is not to say that the Orion ST80 is poorly constructed, the materials used in the Orion ST80 are quite satisfactory, it is just that the Stellarvue Nighthawk is so overbuilt, that you can not help but notice the difference in the construction.

Once set up and in use, I immediately noticed the beautifully smooth action of the Stellarvue Nighthawk focuser. The unit I had has a rack and pinion focuser, which is being phased out and replaced with a Crayford type focuser. The rack and pinion focuser is superb. With a rack and pinion focuser as smooth as the one on this telescope, I see no need for a Crayford focuser. The action on this focuser was outstanding; you never move the scope off your target while focusing. The action on the Orion ST80 focus is o.k., and that is about all I would say about it. It also has a rack and pinion focuser, but it is a little coarse, and you occasionally move off your target while focusing.

The extra heft of the Stellarvue Nighthawk is not across the board good news. The extra weight of the Stellarvue Nighthawk made it just a tad much for the tripod I was using. I tested both of these scopes on a Bausch and Lomb model 68-4020 tripod with a Scopestuff binocular fork #BINA. The tripod is a heavy duty camera/video tripod and teamed with the binocular fork this is the poor man's version of the Televue Telepod. The extra weight of the Nighthawk was not welcome on this mount, although it could handle it if attention was paid to properly balancing the scope by moving it in its mounting ring. This adjustable feature of the mounting ring is nice; however, it prevents the collapsible dew shield from closing all the way.

Of course, the thing we really care about in a telescope is the optics. What is the view like? I made a side by side comparison of the telescopes on the same mount, on the same targets, on the same night, with the same eyepieces. Since the Stellarvue Nighthawk has a focal length that is 20% longer than the Orion ST80's, this means that testing with the same eyepiece will yield 20% greater magnification in the Stellarvue Nighthawk than in the Orion ST80. I tested with several eyepieces: a Paul Rini 35 mm modified Plossl, a 20 mm Celestron Silver top Plossl, 9.5mm and 5.1mm Orion ED, and finally, I added in a Celstron Ultima 2x apochromatic Barlow lens. These are what I consider medium quality/cost eyepieces, and are decent performers for the money.

My observing spot was a relatively light polluted suburban sky, and the moon came up making things even lighter. Here is what I saw:

Mars was in good view over head, so that was where I started. I used the 9.5 mm eyepiece and got a decent view of the salmon colored disk at 42x magnification (ST80) and 50x (Nighthawk) respectively. Not a lot of detail in either scope, but my experience at a star party looking through some very high end scopes was that you don't see a lot of detail on Mars, at least not in 2005. I kicked things up to 78x/94x magnification and I could faintly see some of the dark markings that are the great canyon on Mars. I put in an orange Wratten #21 filter, which teased out a hint more detail. So far, so good. Now I was going to go all the way, and I put the Barlow in with the 5.1mm eyepiece for maximum magnification with the eyepieces I had. My maximum magnification showed less detail than I got at 78x/94x. In fact, at maximum magnification there was no detail at all. This had me concerned since I had assumed the Stellarvue Nighthawk would show more planetary detail than the lower cost Orion ST-80. I knew that magnification this high might push the limits of what an 80 mm scope could handle, but I though the more expensive telescope might take it. Not being sure what to make of the fact that the Stellarvue Nighthawk was showing no more detail than the Orion ST-80, I turned to Alberio.

In case you are not acquainted with it, Alberio is a fairly bright double star that is located in the summer triangle. When you look at it through a telescope, you can see that one of the stars is yellow, and the other is blue, which makes it particularly striking. I took a look at it at various magnifications, going all the way to the maximum my eyepieces allowed. Needless to say, the highest magnification was not the best view due to dimming of the stars caused by the high magnification. I might also noted that the field of view gets small at this magnification, so even a slight bump of the scope means you lose your target. In fact, at 100x or higher, an equatorial mount would probably be the better choice. Alberio looked beautiful as it always does, but I really did not find one scope had an advantage over the other. One of the previously mentioned bumps accidentally brought me over by Vega, and the nearby double-double.

The double double is, you guessed it, two double stars (4 total). However, to me, it had only been a double, because I could never resolve the two pair. That was before I went to a star party and someone with an 8" Schmidt-Cassegrain let me take a look at it. Through the 8" telescope, it was possible, albeit just barely, to see that there were four stars. For some reason, I thought this would be a good test, so I put in the Barlow and went to highest magnification with the Stellarvue Nighthawk. I sawÉ.two stars. I could not resolve the double double. Using the Orion ST80, my results were repeated. With either scope it is a double, not a double double. At lower magnifications, I was getting some nice sharp views out of both scopes, and the double double looked like a pair of car headlights up in the sky. By this point, the moon was high, and I turned my attention to it.

There is a lot to be seen on the moon, and it was big and bright. I started making my climb going from low magnification to high. The moon is bright, really bright, so I had to put in a variable polarizing filter to stop from temporarily blinding myself. When I went to my maximum magnification with a 2x Barlow and a 5.1 mm eyepiece with the Stellarvue Nighthawk, much to my surprise, I did not loose any detail. There was a bright violet halo at the edge of the moon, and a tiny hint of fuzziness, but I was seeing major detail on craters. I mean detail I had never seen before. I was excited, but puzzled given my earlier experience at this magnification with Mars. I decided to try this with the Orion ST80. Wow, I could see a lot of detail! The image was a bit soft, and there was a walloping large violet halo at the edge of the moon, but I had a useable image! This was really shocking to me, as I had never had any success with the Orion ST80 at anything over 80x magnification, and at times 80x seemed to be a stretch. I took a look at a few more objects and decided to think about what I had seen.

I had not seen any detail through the Stellarvue Nighthawk that I could not see through the Orion ST80. The Stellarvue Nighthawk, having a focal length 20% longer than the Orion ST80 was at 20% higher magnification with any given eyepiece, so the images were more magnified, but they weren't any sharper or more detailed than the Orion ST80 images. This was a little hard for me to accept, as I had planned to keep the Stellarvue Nighthawk, and had made this side by side comparison sort of as a due diligence exercise rather than really expecting the Orion ST80 could compete. The Orion ST80 images had always been decent, but I had expected the hand fitted lens of the higher cost Stellarvue Nighthawk to blow the lowly Orion ST80 away. After all, the Stellarvue Nighthawk is twice the price. Well, I had seen it with my own eyes, and despite my prior expectations, the view in the Orion ST80 was really just as good.

Now I had to give some though to the other features. The Stellarvue Nighthawk had a vastly superior focuser. Butter smooth, clearly superior to the somewhat stiff focuser on the Orion ST80. The Nighthawk focuser could handle a 2" diagonal and 2" eyepieces, which the Orion ST80 could not. However with the 35 mm Paul Rini 1 1/4" eyepiece I was down to 12x magnification, so it seemed to me that this was a feature I would not need. The Stellarvue Nighthawk had heavy duty construction, but also extra heftÉ..which made it harder to handle on the tripod I had. I had no desire to get a heavier tripod and give up portability. The Stellarvue Nighthawk was U.S. assembled, and I had received a response to my e-mail questions from the owner of Stellarvue himself. That is the type of service that I was never going to get with the Orion ST80. But when all was said and done, what was going to be the right scope for me? And how come neither scope would work at high magnification on Mars, but they would do it on the Moon?

Some consultation with astronomy friends confirmed my suspicion. At high magnification, the 80mm objective lens does not capture sufficient light to resolve fine detail. Because the moon is so bright, the telescopes revealed detail at high magnification on the moon, but not on Mars. No telescope this size would be able to resolve minute detail at high magnification, no matter how good the optics. This settled my decision. The Stellarvue Nighthawk went back, and I kept the Orion ST80, and put the difference in cost toward an 8" dob.

This is my solution: The Orion ST80 on a camera tripod is a great grab and go scope, and lets me see quite a bit. When the opportunity arises to go to a star party, I will bring the 8" dob and take advantage of the greater light grasp. Would someone be crazy to spend the extra money on the Stellarvue Nighthawk? No, I don't think so, but their priorities would be a little different than mine. If you want personalized service, a truly fine instrument, are willing to go with a little bit heavier tripod, plus spend the extra $225 over the cost of the Orion ST80, then the Stellarvue Nighthawk makes sense. It really could provide a lifetime of enjoyment. However, for me, a two scope solution made sense, and I spent my money accordingly. There are details in faint objects that no 80mm scope can reveal, and I want to be able to see that detail. However, I still like the option of being able to have a grab a scope for a quick look at something from my yard, or to have something compact that I can take with me on vacation. The Orion ST80's low cost allowed me to have two scopes, and the Orion ST80 really is a good little scope, so that is what I chose, and I am happy with my choice.

Rob Nichols