4 replies to this topic

[Baphomet]

Not here to waste any time—straight to the point, my fellow hobbyists. Help me chose my FIRST scope.

 

Perfectionist Tendencies: I'm more of a "best or nothing" person. I don't want a 428 inch scope with mediocre optics, even if it's "the master of chromatic aberrations" (sarcasm intended). Simply put: I don't care about how many craters I see; I care about the details within a crater.

 

Near Future Plans: In a couple of months, I'll definitely be diving into star spectrometry.

 

Experience Level: Though, I'm not a complete newbie—I'm aware that I can't have it all. However, all I want in the end is to perform some star spectrometry and get some detailed views of planets (cassini, jupiter's spot, mars' polar cap). To clarify, I’m not saying I like doing deep-sky object (DSO) and planetary observing equally. Instead, I’m primarily interested in planetary details and just as much, star spectrometry.
Correct me if I’m terribly wrong, but spectrometry doesn’t have much to do with the resolution power or even DSO capabilities of a scope. Rather, it’s a tool for analyzing "the light", right?

 

Budget: $700–$1400 for the scope and mount only. Used scopes are welcome. I’m not a wealthy person, nor do I live in a wealthy country. Thus, when I buy a scope, I won’t be able to sell it for at least 2–3 years. No need to worry about cameras or adapters for now. Alternatively, you can suggest a good-quality scope with an okay mount, allowing me to buy a "better mount" next year. 

 

Portability Needs: I have another house in the countryside with minimal light pollution, and I plan to take advantage of this. Therefore, the scope needs to be grab-and-go friendly. I can’t be bothered with frequent collimations, lugging numerous parts into my SUV, or fidgeting excessively with setup.

 

Options I’m Considering: With my limited knowledge, I’m torn between a 102mm ED/APO and the Sky-Watcher Mak 127 with a GoTo WiFi mount. I defo. prefer a scope with wifi mount!

 

Constraints: The telescope will be bought for me from Japan. Thus, It must fit in regular luggage, shouldn’t exceed 12–13 kg with the mount. The silver lining is that if I go for a reasonably sized wifi GoTo mount (since it’s detachable), my brother can carry the scope in his luggage, and his wife can carry the mount.

Edited by Baphomet, 10 January 2025 - 05:45 AM.

[dawnpatrol]

Moving to Scientific Amateur Astronomy for a better fit. 

[scanner97]

I can't help much with the spectroscopy but I can comment from a general AP angle, which might help a bit - and maybe prompt some other responses.

 

Either a 127 Mak or a decent 102 doublet is going to eat up nearly half of your $1400 budget max, leaving you well under $1000 for a mount.  That would buy you a small tracker that can't really carry the weight you just bought for a scope.

 

What do you currently have for a scope and mount?  My suggestion would be to use one of those for for now and upgrade the other. 

 

If you really need to buy both, a reasonable combination for under $1400 would be something like an AT60ED or AT72ED riding on a Star Adventurer GTI.  Exactly how much you can handle for scope weight will depend on what kind of spectroscopy or imaging rig.  If you're going slitless, that's basically no weight if I understand correctly.  For slit spectroscopy like an ALPY, you'd need to add in the weight of the basic spectroscope + other modules.  For planetary imaging, at least you don't need a cooled camera.  But maybe you do for spectroscopy?

 

Just some random thoughts.  Hopefully a few folks doing this work can add more value!

Edited by scanner97, 10 January 2025 - 03:42 PM.

[Baphomet]

@scanner97

Thanks for the inputs.

Yes, basic SA100 type of thing (never done spectroscopy before), I'll be into.

 

To many people's surprise, it's gonna be my first scope, lol.

 

After having read some more 5+ hours, (unless I got no other option) I won't be buying an apo/refractors for them needing a really proper mount. Also, I got some herniated discs on my lumbar, hence limited leaning and standing...So, if the consensus is a MAK, then I would be fine with a tabletop go to mount wifi like SW MC127 Virtuoso GTI 

[scanner97]

Not knowing much about spectroscopy, I'm grabbing this from the SA100 web page.

 

To use a Star Analyser grating, you should already be able to capture images of deep-sky objects.   You need to be able to locate specific stars in the sky. And you need to be able to capture images of them that are properly exposed, well-focused, and not smeared from their movement through the sky.

 

I doubt you'd be able to do that with any scope/camera on a Virtuoso, since it's an inexpensive altaz mount.  1500mm focal length should make it much worse.  Unless there are folks here who can confirm that the information on the website is incorrect, and spectroscopy really doesn't require typical DSO-type exposures, I suspect you need to focus on an EQ mount that can track and guide, and also think about a shorter f.l. scope - at least when getting started.  A Mak would be ok for planetary I expect, but 1500mm would be a really rough road to start out in DSO-type imaging, which this seems to need.

 

If you just want to get your feet wet, an SA GTI will give you the ability to track and guide, and should be able to handle in the range of 8-9 lbs total payload for an imaging rig like this.  A smaller doublet refractor should work ok for this, I imagine.  With a f.l. of 400-500mm, it will also be much easier to handle as a first experience at this kind of longer exposure. 

 

The challenge will be that, to guide properly, you will also need a computer connected to the mount that is running the guide software, along with a guide scope and guide camera.

 

It may well be that you can do some limited spectroscopy with 30-second or shorter exposures, which wouldn't need guiding.  (And you definitely don't need guiding to scratch your planetary interest.)  But you really need someone who knows beginning spectroscopy to weigh in here and tell you exactly what the minimum hardware requirement is.

 

I wish I could be more helpful.  About all I can suggest is that you not spend any money until you get better advice than I can offer.

 

Good luck!

Edited by scanner97, 10 January 2025 - 05:36 PM.