Looking for a more portable alternative for my Orion XT10 when I'm feeling lazy.

[jbweimar]

Hi,

I recently bought a 10" Dobsonian (Orion XT10). I'm very happy with it but I would like to also buy a more compact telescope for mainly lunar and planetary viewing (so I don't have to carry out the 50 pound beast every time). My budget is around $1k.

I currently have the following eyepieces (worth mentioning):

- ES 82 deg 6.7mm & 11mm (1.25")
- ES 68 deg 28mm (2")
- Baader Hyperion Zoom Mark III 8-24mm with matching Baader Hyperion Barlow (2.25x)

I'd like to scope to be portable in contrast to the 10" I already own. Initially, I was thinking of a refractor telescope (less maintenance, smaller). Something like the EvoStar 120/1000 (400 dollars). I would then buy a sturdy tripod (also 400 dollars) to accompany it. But then I started looking into the Newtonian models, like the Sky-Watcher 130PDS which is only 250 dollars but has 130mm of aperture.

I hope someone can give me some sound advice. Let me reiterate all my criteria, conditions, limitations:

• I'm in the city with light pollution.
• Weight is no issue, size is.
• Budget is around $1k. (Note that I already have some eyepieces.)
• I might want to take some photos/movies but I'll primarily use it for viewing.
• I want it to come with (or recommend one separately) a really sturdy tripod that allows me fine control over the movement. (That can take at least the weight of the scope + my Barlow and zoom eyepiece.)
• An AZ mount for simplicity is preferred. (But perhaps someone can convince me otherwise.)
• I would use it mostly for viewing the brightest objects in the sky (Sun, Moon, planets, some of the brighter M-objects). I want to see Saturn's rings!
• If it comes with a carrying case (or if one can be purchased for it), that would be a plus.
• I'm not afraid of collimation. (And by the way, is it true that you don't need to collimate a refractor at all?)

Thanks!

[CamelHat]

You need something with a long focal length such as a Mak. LP will not be a serious issue for planets.

[jbweimar]

Thanks.

If I look at an APO such as:

EVOSTAR 100ED DS-PRO FPL53 APO

and a Mak such as

Messier MC-100/1400 OTA

Then the APO is 4 times more expensive ($800 vs $200) than the Mak. Will that APO's image quality blow the Mak's away at the same aperture?

[jbweimar]

Actually, a good contender right now for me is:

SKYMAX-127 127MM (5") F/1500 MAKSUTOV-CASSEGRAIN OTA

with a yet to be determined mount, either AZ or EQ... not sure yet. I'm worried the EQ might frustrate me too much and as photography is not too important at this point I'm still tempted to go towards the AZ mount. Also, the Skymax-127 is quite light, so I'm not too worried about the AZ construction. Thoughts?

[CamelHat]

I don't think the APO will blow the Mak away. 1500 mm is where planet observing begins, ideally you would use a 2500-4000 mm SCT but that exceeds your budget. If you use that Skymax 127 you will need to add a Barlow. The mount will have to be stable and without tracking the object will fly through the FOV so I would get the whole system Sky-Watcher SKYMAX-127 SynScan™ AZ GOTO 127mm (5") f/1500 cOMPUTERISED MAKSUTOV-CASSEGRAIN - Optical Vision Ltd . When you say photography, think about a webcam-like system that records video at at least 120 Hz, then use Autostakkert to stack it. Plain photography is much less successful. Keep in mind that this is still a low end system so you may want to visit an astronomy club star party to get an idea what to expect before you buy. Also keep in mind that you depend a lot on the atmospheric conditions so there are only a few nights per year when it works well.

[Reddog1972]

I'm very interested in this thread and reading more, as I feel like jbweimar is reading my mind. I too have an Orion XT10 (goto version - which is 70 lbs lol) and I'd love to read the responses.... I never before considering a Mak/Cass but I can see the appeal.

[Leveye]

A simple Mak style scope rig like what Orion or Celestron sells would work great. Save you some money as well.

[jbweimar]

Would I really need a Barlow? As I said, I have the ES 82 6.7 and 11mm. The 6.7 would give me nearly 225x magnification. Correct me if I'm wrong, but I don't expect that I can do any better with my LP. I could always get the ES 82 4.7mm to get 320x if you think I can do better. I'm hesitant to getting a GOTO system because I prefer not to have to deal with electronics/batteries. If I remove the GOTO, would you still suggest the AZ mount over the EQ mount?

[jbweimar]

One part of the equation that I didn't discuss yet is the cooling down of the mirror. For the Skymax I mentioned above, how long might this be? (Say 20C indoor and 5C outdoor) I guess refractors are easier this way, correct? I guess for grab-and-go, one could argue that this would be an important factor. In fact, how much worse are views when the mirror hasn't cooled yet? I'm talking mainly about planetary/lunar observations here, though I'd also be interested in hearing about DSOs.

[CamelHat]

Would I really need a Barlow? As I said, I have the ES 82 6.7 and 11mm. The 6.7 would give me nearly 225x magnification. Correct me if I'm wrong, but I don't expect that I can do any better with my LP. I could always get the ES 82 4.7mm to get 320x if you think I can do better. I'm hesitant to getting a GOTO system because I prefer not to have to deal with electronics/batteries. If I remove the GOTO, would you still suggest the AZ mount over the EQ mount?

I had prime focus (webcam) photography in mind when I mentioned the Barlow. For visual those eyepieces should work fine. When tracking you need 1 control with an EQ mount, 2 with an Alt/Az. I find Alt/Az is easier to use than EQ otherwise but others may disagree.