A short recap: Last September I went to a huge public star party sponsored by several local amateur astronomy clubs in SE Michigan. That night I got hooked and the next day I started researching scopes and planning to buy my first one. After some time I determined that my 2 main criteria were the ability to see DSOs as well as portability (with some ability to also view the planets and moon when the desire hit me) so I settled on Orion's 120mm f/5. In November of 2008 I posted this inquiry on CN asking for some advice and guidance regarding accessories and whatnot. I received a lot of really great advice from the 120ST fans on CN!
So, after saving up for months, a couple of weeks ago I bought the following items:
1. 120ST OTA (Orion)
2. AT Voyager alt-as mount (Astronomics)
3. 2" Dielectric Diagonal (Orion)
4. EZ Finder Delux (Orion)
6. 13mm Ethos (Orion)
7. 4.3mm W70 Antares (Agena Astro)
8. A 5.91" (150mm) lens cap (Agena Astro) (To build a stop down mask)
(My thanks to Doctor Noodle for the specifics on how he made his stop down mask here. I also saw that he liked the Antares eyepiece for planetary viewing which led me to try that one also.)
I've had the OTA, mount, 4.3mm eyepiece and a 25mm 1.25" Kelner eyepiece (found in the basement) for over a week now and the Ethos finally arrived last night. It has been mostly cloudy here in SE Michigan for weeks now, but I have had a few clear nights with the new scope, including last night with the Ethos. However, it has been bitter, bitter cold here and each of my viewing sessions only lasted 15-20 minutes each, so my experience with the new rig is quite limited so far. But, I'm pretty excited about it so I wanted to post my first thoughts as well as some concerns I have.
But first, here are some pictures:
The whole kit-n-caboodle.
The eyepiece end.
The business end.
Here's the stop down mask.
And here's the back side of the stop down mask. I found that those little blue Lego pieces were just right to shim the cap down to the perfect size. (I did not cut the hole in the cap myself. I work for a small laboratory where they have a computerized mill. One of the scientists there spent over an hour programming, testing and then cutting an 80mm hole in the cap for me.)I also purchased a small notebook to keep a record of my viewing sessions. I thought I'd report on my time so far with the 120ST to highlight what I like and don't like about it so far.
On my first evening out (2/1/2009), it was actually fairly cloudy. I couldn't see the stars, but the moon was visible through the haze. I didn't have many expectations, but I was dying to try the scope out so I bundled up to brave the cold.
First I tried the 25mm Kelner (24x). I really didn't have high hopes about this cheap, old eyepiece, but even though the crescent moon was partially obscured by the hazy cloudcover, I really saw a surprising amount of detail. I was pretty impressed. Then I tried out the 4.3mm Antares on the moon (140x). It was really too powerful an eyepiece for lunar work. At 140x the image of the moon was larger than the field of view and I wasn't able to focus in on the details at all. Everytime I touched the focuser the whole image would wobble for several seconds. I had to focus a little bit and then wait to see if it focused properly and then try again until I got as close as I thought it would get. Not a lot of fun. 24x was much more pleasant.
That night I noticed two problems with my setup. First, the focuser is a weak point at higher powers. It is so stiff that the effort involved in changing focus to set the whole rig to trembling. This may be improved by putting wooden, instead of aluminum, legs on the tripod, but the main problem seems to be the focuser. The second problem was not with the scope, but with the location of the fine tuning knobs on the AT Voyager. Well, the location of the knobs themselves is ok, but when the extend-o'-cable is added to the azimuth fine tuning control it is positioned poorly. Here's a picture.
It is a bit hard to see, but what happens it this: When you raise the scope to point high in the sky, the handle of the fine tuning cable smacks right into the focuser knob. That in itself is just kind of annoying. You have to pull the cable out of the way every time you raise the scope to view high. The other bothersome part is that the fine tuning cable is very thick. After you have pushed it out of the way it rests firmly against the body of the scope and applies pressure on the OTA. At low magnifications I don't think it is necessarily a problem, but at high powers I suspect it adds to the shaky nature of the image. I may have the cable installed improperly, but I don't know where else to put it except on the opposite side of the support arm where it is impossible to reach. I tried placing the extension cable on the altitude knob, but then the azimuth knob is harder to reach. I'm not sure if others have had this problem. I guess I could try bending the cable, but I'm a bit worried about damaging it.The next morning at 6am (2/2/09) the skies were totally clear, but it was still bitterly cold. I dragged myself out of bed early just to view Saturn. (I used StarryNight the night before to figure out when and where I could see it best if the clouds went away.) First I tried out the 25mm Kelner again and could just barely tell that it was a bright dot with a diagonal line through it. Then I tried out the 4.3mm Antares and got a better view. It wasn't what I would call "great" but I definitely tell it was Saturn. I couldn't see any real details, though, and the rings were pretty much edge-on so it looked like a slightly bigger, smudgy circle with a line through it.
Again, the focuser proved its shortcomings. I just couldn't get a distinct image. However, one thing I did not notice, which I had expected, was the purple fringing of color aberration. I only stayed out a few minutes due to the cold, but I felt that with a better focuser and more time I could have seen a more distinct image. However, I'm not sure if 140x is really enough to see a lot of Saturn, but I'm not sure if the scope can handle a lot more than that yet.
A couple of nights later, on 2/4/09, I finally got some evening time with clear skies. I mostly work late afternoons and evenings so coming home from work and then hauling the telescope outside before settling down with the family works out well. That night I tried the 25mm Kelner on the moon again and was again impressed with the clear, beautiful image. Focusing was still a bit problematic, but not terribly so. Again I so no color aberration.
The moon was pretty high in the sky and was nearing 1/2 full so not only was I dealing with harsh city lights (I live not far from Detroit) but the bright light of the moon was also making for poor seeing. Because of my inexperience, the cold and the bright sky I was limited to viewing things I could see easily. So after the moon I found my way over to the Pleiades (M45). Because it was near the moon it was not terribly visible to the naked eye. However, the 25mm Kelner really brought out a lot of detail. It was pretty nice.
After that I popped the 4.3mm back in and pointed at Venus. Again I had a hard time focusing, but this time I also got a big eyeful of purple fringing for the first time. I threw on the 80mm stop-down mask for the first time and this cut the ca down by about 1/2. I could definitely see Venus' crescent shape though, which was kind of neat. I will definitely need a fringe filter of some sort, though, if I keep pointing it at the brighter objects. I'm curious to see how Jupiter will look, but it isn't visible right now.
This was also the evening when my wife came outside with me for the first time and had a look for herself. She did a lot of "oooing" and "ahhing" over the moon and Venus. She seemed pretty impressed and we had fun later planning to take the scope camping with us this coming summer (which is mainly why I wanted a more portable scope in the first place.)
Then, last night, at long last, FedEx finally delivered the 13mm Ethos, which had been on back order from Orion. I have to say I have mixed feelings about buying such a premium eyepiece. It feels a bit silly to pay twice as much for an eyepiece as for the OTA. But, at the same time, if I stay with this hobby for a long time, it makes sense to me to buy a few high quality eyepieces which I'll likely keep forever and which I can use in any scope I might buy later.
So, last night, 2/5/09, I hauled the rig back out in the back yard and plugged the Ethos into the diagonal. I have to say... Wow, this eyepiece is big and heavy. It is very impressive just to hold in your hand.
The first thing I looked at with the Ethos was the moon, which was approaching 3/4 full and was still very high in the sky, drowning out almost everything else. The view of the moon at 46x with the Ethos was noticeably different than through the Kelner at 24x. First, the image was much larger and much brighter. Second, the moon looked much more 3-dimensional than in the Kelner. Now, that being said, I had some difficulty finding the right eye placement over the Ethos. It was a bit awkward. I hope that gets easier with practice, but it was a little odd the first time.
Also, after just a few seconds my eye started watering and hurting. The image was just too bright and a bit painful. So, I stopped the mask down to 80mm, but it still hurt my eye. When I used the original lens cap and removed the built in 50mm mask cap I finally got an image of the moon that was just as beautiful as before, but not quite so painfully bright. I could actually manage to look at the moon for a couple of minutes without having my eye water profusely.
After that I tried to look at the Pleiades again, but the moon was too bright and too near it and I couldn't even get a bead on it through the EZ Finder Delux. (Also, looking at the moon had hurt my night vision considerably.) But, I could find Orion's belt well enough so I swung over to M42. Once there I took a few minutes to compare the 13mm Ethos with the 25mm Kelner and was again impressed (after removing the stop down mask). The Ethos showed a lot more detail of the M42 nebula, although the city lights and the moon still interfered quite a bit.
I'm still a bit on the fence about the Ethos. I will probably keep it, but there are a few things about it that make me wonder. I really think I need more experience with it when it is warmer and I'm less hurried, but I did find the eye placement a bit more difficult than with the Kelner. The image is much better, and more 3-D like and has a considerably wider FOV, that is true. My big trouble is that I lack experience with other more similar eyepieces. I wish I could compare it with a 12T4 or a 17T4 or even a larger eyepiece from the Orion Q70 line. I just don't know enough to be able to say for sure that the Ethos is worth the extra money over these other premium (and not so premium) eyepieces. I could exchange the Ethos for a similarly sized Nagler and still have enough left over to buy a new focuser. I need to spend more time with it to be sure.
Also, the moon in the Ethos is almost TOO big and majestic. Looking at the moon through the Kelner I said to myself: "Wow, that's a really nice clear view of the moon." But, looking at the moon through the Ethos I said to myself: "Holy cow! The moon is going to fall on me!" It was a bit overwhelming. I wonder if it would be more subdued in the 17mm Ethos. To bad that one costs so much more, even than the 13mm. Something to consider though. The 13mm Ethos might be too much power for the 120ST. It's too early to say, though. I need to view more clusters and nebula to really get a feel for that. Or perhaps I'll try out a larger Orion Q70. Those are only about $100.
Overall I'm very happy with the 120ST so far, even though I've just scratched the surface of its potential. The OTA on the AT Voyager mount is very easy to pick up and carry outside. Not counting cool down time, I can have it set up and pointed at an obvious object in the sky in less than a minute. And, if I want to move around the yard it's as easy as picking it up and moving it. Nothing to it. The EZ Finder Delux is very easy to use, except that it does take some bodily contortions to line it up high in the apex of the sky. The whole rig is extremely portable and easy to use. I can't wait to have warmer, darker nights so that I can take my time finding my way around the host of star clusters, nebulae and brighter galaxies that I hope to see one day.
I've also been reading Turn Left at Orion and have just ordered Sue French's Celestial Sampler and am planning out my stargazing once the weather gets better. In addition I've been reading the Wikipedia entries on the Messier list, the Caldwell Catalog and the Herschel 400 Catalog so that I have lots of things to try to find later this year.
I'm really looking forward to improving my knowledge of the night sky. For the long term I'm also considering a big dobsonian to compliment the 120ST.
One step at a time, though.
My apologies if this was much too long. But, I'm having a ton of fun with this new hobby and I've never been good at being brief when I'm having this much fun.
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