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That New Telescope the non-astronomy spouse has greenlighted...

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#1 Jesse62


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Posted 20 October 2019 - 05:55 PM

Hello everyone!

I'm thrilled to be part of this group. Been watching the skies for a little over fifty years...I need some unbiased opinions on my next purchase!

I have the Celestron C150mm f/8 refractor (had it for over eighteen years). It's a workhorse, IMHO; great for low to medium power views of DSOs as well as the planets and moon. The FOV with my 2" 36mm eyepiece is 2.1 degrees! However, as everyone knows, the chromatic aberration is aggressive on bright objects. I've stepped the aperture down to 102mm, viewing the planets, effectively making it an f/10, but of course the trade-off is a dimmer object.

Since I'm not dumb enough, given the chance, to gaze through a triple-lens apochromat of the same aperture-and cannot afford to spend thousands of dollars on one-I've pretty much decided on Orion's 180mm Maksutov as the scope for high-power viewing. I think it would wonderfully complement my Celestron refractor.

I started to call Orion, but of course I'd get a gushing (somewhat biased) endorsement of their instrument. Hence joining this group, where I can get objective (pun intended) advice.

Does anyone here by remote chance have both of these instruments? If not, has someone had the opportunity to gaze through both, approximately the same magnification (in my case, 200X), at Jupiter or Saturn? Would the Mak yield a better image of those objects, versus what I've been accustomed to with my achromat...sufficiently enough to justify spending a thousand dollars? My wife has grudgingly agreed to the purchase, but said, "Get it right this time." (why couldn't we all have met our spouses at a star party???)

I suspect I'm dealing with either the relative mediocrity of mass-produced Chinese optics, regarding my refractor, coming into play at high magnification, CA really starting to factor in, or both.

Any opinions would be welcome. I'm so glad to be a part of this forum!

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#2 coopman


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Posted 20 October 2019 - 06:16 PM

I've never had a Mak, but the improvement in sharpness should be very apparent over the CA smeared detail that the refractor produces.  The Mak will take much longer to cool down and provide good views.  Most people are covering their cat/cass OTAs with reflectix or some other insulating material to minimize the effects of that, and it seems to be working well.

Do a search for "180" and you should get lots of comments on the Mak. 

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#3 StarBurger


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Posted 20 October 2019 - 06:19 PM

Oh lucky man!.. in some respects...

A wife that appears to know her Mak from a frac can be dangerous though.

You had better get it right or else!

I own only that same frac and cannot advise on the Mak but there will be good advice coming that will enable you to navigate this mine field.

#4 Rustler46



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Posted 20 October 2019 - 06:31 PM

I applaud you for asking the ins/outs (+ or -) of your future purchase. I'll add some other things you  might consider:

  • 150mm to 180mm is a relatively small increase in light-gathering power and resolution. Perhaps an 8-inch SCT or MCT would be a possibility.
  • An SCT also gives ability of high power viewing, similar to an MCT.
  • Since I've never owned a MCT, my bias is towards the SCTs having owned the 3 shown in my signature block (5-, 8- and 11-inch).
  • The SCT may have less problems dealing with thermal and cool-down issues.
  • If money is preventing going for a larger aperture, perhaps the used market would be of help.

I hope it all works out for you!



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#5 M11Mike


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Posted 20 October 2019 - 06:44 PM

Agree --- hard to beat a 8" SCT.  Lots of power / lots of aperture / NOT a lot of $$$.  


Used 8" OTA's can be had for the price of a single expensive EP.   


I don't think this guy will be happy with the much smaller FOV from a 180 MAK vs. his F8 refractor FOV he likes.


Plus you can get a F6.3 focal reducer that with his 36mm EP will almost match what he's getting from the frac.



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#6 Richard O'Neill

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Posted 20 October 2019 - 06:52 PM

"Would the Mak yield a better image of those objects, versus what I've been accustomed to with my achromat...sufficiently enough to justify spending a thousand dollars?"



Well, therein lies the rub without actually looking through one, side by side with your refractor. A Mak would be the choice for me but perhaps not so much for a more frugal observer, that is unless CA free sharper planetary images are what you crave. Since you can have both why not give it a go and see for yourself.


BTW, I have both instruments and think the pair compliment each other rather nicely. Good luck with your decision.




PS. Having owned several C-8's I don't discount that option but the Mak will deliver sharper planetary images, hands down!

Edited by Richard O'Neill, 20 October 2019 - 06:59 PM.

#7 Hugh Peck

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Posted 20 October 2019 - 07:54 PM

If you already have a 6" you might consider the C-9.25. It's close to the 7" Mak in size, weight and price but would be a big step up in aperture. 

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#8 Eric H

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Posted 20 October 2019 - 09:07 PM

If the Mak is your choice, it's a great one. I've owned both scopes and the little 7" Mak far outshined the 6" CR. You get a cleaner image once acclimated, none of that annoying CA, and more power with wider eyepieces. Perfect for planetary and bright stuff.

#9 greenstars3


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Posted 21 October 2019 - 02:54 PM

Take a look at the Tak Mewlon telescopes they do "Get it right this time."



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