More thoughts on the 120ST

I got a lot of great feedback on my CN post reprinted below. Here is my followup which will also be simul-posted on the CN forums.

Thank you all for your responses and advice. Even (especially) the constructive criticism is appreciated. I do feel a bit silly for spending so much on the eyepiece (2x what the OTA costs!)

I’ve spent some more time looking at the moon through the Ethos and I’ve been more and more troubled by, well, not the view, but the awkward viewing through the eyepiece. The view is stunning, but the Ethos seemed very picky about head/eye position and I had to move my head in and out and back and forth to get the good image. I spend much of the day yesterday thinking that I should return the Ethos and either get several less pricey eyepieces or maybe a 12T4 (or a 17T4) plus a new focuser.

My goal with the premium eyepiece was two-fold. First I wanted the best wide field image I could get to compliment the 120ST’s natural wide field, deep space views. Second, I’m guessing that I will end up buying or upgrading to new scopes in the future. I don’t mind spending the extra money on the eyepiece now if it will grow with me as my skill advance. Better that than spend even more money later upgrading both telescopes and eyepieces.

But, like I said, I spent yesterday thinking that maybe I should just return it and explore other options. Besides, in a way, an Ethos on a 120ST is kind like seeing Grace Kelly out on a date with a guy like... well, me. Something’s just not quite right. (Sort of like the Christie Brinkley / Billy Joel syndrome...)

But, then something happened to change my mind. First, I did a bunch of research last night and stumbled upon this thread over in the eyepiece forum. The long and short of it was that the OP on the thread was having the same trouble I was having with the 13E. He found viewing the moon to be troublesome and uncomfortable. The advice he received was to spend some time looking at DSOs instead and that this type of viewing would be more comfortable. Apparently the bright moon caused extra pupil constriction in the eye which did not match up well with the exit pupil on the Ethos, causing the need to move the eye and head back and forth. But, on less bright objects the eye’s pupil is wider which allows for more comfortable viewing.

It just so happened that last night was not only cloud free, but also much warmer than it has been here in Michigan. (It felt like 20 degrees rather than -5 degrees... almost beach weather!). So, after everyone went to bed I brought the 120ST and the Ethos back outside to give the relationship another chance. The only trouble was that the moon was full and near apex which drowned out nearly everything else in the sky (along with the horrible Detroit light pollution I live under). But, I could find M42 and M45 easily enough so I spent about a half hour just studying those two.

What a difference! I had looked at the Pleiades and the Orion Nebula before in the past week, but it had been so cold I couldn’t relax and enjoy it. Now that I had time to enjoy the viewing without freezing to death, I found the Ethos much more comfortable. Not only that, but I really started to see what all the fuss was about.

Unlike the moon, when viewing DSOs through the Ethos I found the experience much more like looking through a window. I could see a lot of detail out of my peripheral vision, and I was able to tilt my head and move my eye to examine those images off to the edge. And, of course, the field of view is just stunningly huge. Unfortunately, because of the nearly full moon I was not able to see a lot of detail in M45 or M42, but what I was seeing was sharp as a tack from the center of the view to the edge and was just stunning.

Now I just need to get rid of the full moon, get away from the light pollution and learn how to find more DSO’s than just the easiest ones.

So, in the end I think I’m going to keep the Ethos, even though people will see us together and say: “What is SHE doing with THAT guy?” It does mean that it will take me that much longer to save up for the new focuser and the filters and any additional eyepieces I may want. But, I feel now that I have the backbone of a very nice, portable rig to view the night sky with. It may not be the best scope for planetary viewing, but my interests are more remote anyway.

I’m starting to think about it like this: I bought a really great eyepiece that allows really stunning views of the night sky; the kind of eyepiece you might consider a family heirloom. So, to accessorize my fancy new eyepiece I hooked it up to a cute little portable telescope so I can take my Ethos camping with me to beautiful dark northern Michigan skies once summer comes. :)

Here’re a few additional items that are on my mind about the 120ST:

1. The EZ Delux finder is great. However, for things near the apex I have to get down on the ground to line up the sight. Maybe a right angle finder would work well in conjunction with it. Maybe an inexpensive 38-40 degree eyepiece would work just as well or better as a finderscope (from Orion’s Q70 line, perhaps?)

2. The fine tuning controls on the AT Voyager started acting up last night. In some positions either or both the altitude or the azimuth adjuster stopped working. When this happened it only affected one direction. I could move it down but not up or left but not right. After experimenting I found that this was happening when I had the Ethos on the scope, but it worked fine otherwise. So, I figured it was a balance problem. I shifted the scope forward in the tube rings and this seemed to have improved the situation. I hope nothing is wrong with the mount. That would be annoying.

3. A minor annoyance. I’ve found that I much prefer sitting to standing or kneeling while viewing. I have a nice cheap, collapsible chair to view in, but the height of the eyepiece is much different at apex than at about half way up from the horizon. This means I have to change the height of the tripod legs in order to remain seated to view what I’m viewing. Not a huge deal, but cumbersome. I think this will encourage me to pick one object and spend a lot of time studying it rather than bouncing around the sky. This is probably a good thing, but I wish I could just crank a handle and have the scope raise and lower while I sit in my comfy chair.

4. The eyepiece holder of the diagonal often resists pulling the eyepiece out. It sticks and forces me to wiggle it around after unscrewing the restraining knob all the way. (It is Orion’s 2” dielectric diagonal.) I don’t like wiggling, twisting and turning the Ethos when I try to pull it out of the diagonal. I may return the diagonal for a different model.

5. Once I save up enough, I plan to get a new focuser. Although it is expensive, I am thinking seriously about the Moonlite. The reason for this is not only because it has a great reputation, but also because it comes with an optional shorter than normal draw tube. After some research I’ve learned (and concluded myself) that the 120ST’s standard draw tube cuts into the light cone, effectively reducing the scope’s aperture. I believe that a short draw tube focuser may reduce or eliminate this problem. (I discussed this problem in another thread over here.)

6. I want to try some different filters, to improve images of the moon and to reduce CA, but so far stopping down the lens has improved the view of the moon and I’ve only seen CA on Venus. In fact, I haven’t observed CA on anything but Venus. I haven’t seen that purple fringing on any stars, on Saturn or on the moon. Maybe it’ll be more of a problem once I’m out under darker skies, but not so far. I’d like to get a v-filter, but I think I’d rather get the focuser first.

7. Regarding future eyepieces to accompany the 13mm Ethos and the 4.3mm Antares, I’m considering an inexpensive 2” 32-38 degree “finder” eyepiece, something of a bit better quality in the 20-30 range and perhaps a 2x or 2.5x Barlow. I’m thinking that this may be all I need. At this point it seems like the 13E may cover the 10-20mm range. And, a 2x Barlow will jump the Ethos up to just under 100x, which, in theory, might turn it into my planetary eyepiece. This is all conjecture given my beginner status. I need more experience to make sure, but it’s fun to develop theories to test out.

8. Wayne W. mentioned the color of the OTA earlier. I was surprised and delighted when I opened the box and it was black instead of gray. I assumed I was getting a gray one because I didn't buy the scope/mount package, but I guess not. I'm very pleased. It does look cool.

9. Mr. Wang, thank you for the information about filters. I've bookmarked it for more careful reading later. Everything on that page was information I didn't know. Very helpful!

10. I wish I could have tried both the Porta Mount and the AT Voyager before buying. The Porta Mount looked a bit more portable but the Voyager looked more stable. For those considering it, I do really appreciate the Voyager. Aside from the poorly located azimuth extension cable, the only thing I question is the length of the legs. They just seem a bit too short. I may have to take Wayne W.'s advice and pick up the 8" mount extension tube. Alternately, I hear people have had good luck swapping the legs out with wooden legs from Hands On Optics over here. I need to look into this more.

Oh, and Doctor Noodle, I'm pleased to see that we have more than one hobby in common. I quite like your model work as well!

I can’t wait for more warmer weather and darker skies. Then all my effort into researching equipment can shift gears into researching DSOs.