14 replies to this topic

[farondc855]

Hello,

 

I've been in visual astronomony for more than 40 year off and on.   I currently own two refractors and a larger dobsonian.   I'm considering a Mak or Cassegrain.   I'm considering a 9.25 inch Celestron for visual and photography of the planets.   Although I see great reviews on Maks but few options available Sky Watcher is the only one that I know about currently.   Has anyone done side by side comparisons of both designs?   Any opinions about which might be better for visual or photography?  Thank you for sharing your expertese.

 

Best Regards,

 

Doug Faron

[Matthew Ota]

My understanding is that Maks are better for planetary viewing and imaging versus the SCT as the secondary mirror on the meniscus corrector plate is smaller and thus the system displays better contrast on planetary features. But since I am an old astronomer, modern technology may have rendered this point to be obsolete.

I own an ED refractor and will soon own an 8 inch SCT, and I will make comparisons side by side viewing Jupiter to see if there is any difference.

I also own a 4 inch Maksutov so I can use that too for comparison.

I have a 16 inch DOB but it is huge and I am looking to sell it eventually.

[Mike G.]

I think you will find that most owners of the C9.25 are pretty happy with the images they put up.  I know I always am wowed by mine when the skies are good.  Not saying a 7 or 8" mak might do better, but as Big Daddy Don Garlits used to say, "there ain't no substitute for cubic inches".  Or in this case, square inches...  The C9.25 just might be Celestron's best telescope of all time for all around value and optics.

[tturtle]

I think that a maksutov with a comparable aperture to the 9.25 is a much heavier scope so that is a pretty big issue affecting the mount selection. I use my 9.25 with a binoviewer a lot in part because it fits my viewing style very well. I have trees and light pollution in my backyard so I have it mounted on an alt az non goto setup and I view the planets a lot. It would be hard to imagine a better setup for these conditions. With the binoviewer I can sit very comfortably scanning large parts of the sky and view for very long periods of time at fairly high magnification (>300x) and the amount of detail and color is impressive.

Edited by tturtle, 09 February 2025 - 04:51 PM.

[luxo II]

I think that a maksutov with a comparable aperture to the 9.25 is ...

An MK91 (Intes or Santel versions). 228mm f/13.5, weighs 13 kg. Fixed mirrors, no flop, focuser on the rear, 1/8 wave P-V for whole system.

Only 28 were built, and of those I'm only aware of 6 in active use so quite rare and hard to find, though occasionally one appears on Astromart.

 

Mewlon 250 is the nearest equivalent in production 

Edited by luxo II, 09 February 2025 - 05:49 PM.

[Dave Novoselsky]

I’m visual only and like you have always been heavily invested in the refractor world.  My 2 cents says that price not taken into consideration, the C9.25 is going to suit you best.  The only 7” Cats in current production are the 180 Synta built Maks sold under the Celestron and Skywatcher label but other than cosmetics, twins.  Takahashi offers the 180 Mewlon but it’s a bit hard to get as it seems to be on perpetual back order as is it larger and equally excellent 250 brother.

Again, I am also planetary and lunar and visual only so my recommendation of the C9.25 is based on my use of that and my Skymax 180 for that and not for AP.

 

Good luck.

[maniack]

The Mewlon is a Dall-Kirkham cassegrain design and kind of its own category. It's not exactly easy to find, and collimation might be a bit difficult compared to SCTs.

 

Between the C9.25 and Skymax 180 (the largest mass-produced maksutov) I'd expect the 9.25 to outperform the 180 for every target (in good seeing) despite the smaller central obstruction of the mak. The weight is similar, the 9.25 has a shorter focal length, and the 2 1/4" aperture advantage is significant.

[Dave Novoselsky]

The Mewlon is a Dall-Kirkham cassegrain design and kind of its own category. It's not exactly easy to find, and collimation might be a bit difficult compared to SCTs.

 

Between the C9.25 and Skymax 180 (the largest mass-produced maksutov) I'd expect the 9.25 to outperform the 180 for every target (in good seeing) despite the smaller central obstruction of the mak. The weight is similar, the 9.25 has a shorter focal length, and the 2 1/4" aperture advantage is significant.

Sounds right

[ABQJeff]

C9.25 > 7” Mak for visual and AP. Same weight, but aperture rules (and it’s F/10 vs F/15 to boot!)

Now that that is decided. Let’s discuss merits of getting an Edge version ;-)

[bobhen]

The Mewlon is a Dall-Kirkham cassegrain design and kind of its own category. It's not exactly easy to find, and collimation might be a bit difficult compared to SCTs.

 

A Mewlon is no more difficult to collimate than an SCT. I've owned both.

 

Bob

Edited by bobhen, 10 February 2025 - 08:25 AM.

[bobhen]

Hello,

 

I've been in visual astronomony for more than 40 year off and on.   I currently own two refractors and a larger dobsonian.   I'm considering a Mak or Cassegrain.   I'm considering a 9.25 inch Celestron for visual and photography of the planets.   Although I see great reviews on Maks but few options available Sky Watcher is the only one that I know about currently.   Has anyone done side by side comparisons of both designs?   Any opinions about which might be better for visual or photography?  Thank you for sharing your expertese.

 

Best Regards,

 

Doug Faron

For visual planetary, your 152mm ED refractor will equal and probably best a C9.25 on most nights, especially at your location. If the seeing is really excellent, your larger Dobsonian should also best a C9.25. And, a SCT will need an aggressive acclimation strategy; wrapping the tube in insulation or adding fans. The same goes for a Synta 180 Mak. 

 

For planetary imaging, a C9.25 will be excellent. These days, with digital post processing, getting really nice planetary images does not require high quality optics just reasonable aperture and some FL. 9.25", 11" and 14" SCTs fill the bill nicely. Unless you can find and have the budget for a large and very expensive Mak, the C9.25 would be a fine choice for planetary imaging.

 

Value-priced SCTs and value-priced Maks (like those from Synta) will be close in visual performance. But, if you can find a high-quality Mak (like the Astro-Physics Mak or the like) and have the budget, it will best both.

 

Bob  

 

 

Bob 

[Dave Novoselsky]

A Mewlon is no more difficult to collimate than an SCT. I've owned both.

 

Bob

As have I and I agree.  Part of the myth of impossible to collimate comes from Ed Ting who had a problem long ago.

[farondc855]

Hello, thank you for all the good comments. And is definitely solidified my thoughts around the 9 and 1/4 SCT. Although I truly love my refractors, I need a little bit more aperture to hopefully see more details on the planets. And the 9 and 1/4 in SCT is pretty lightweight also which is in its favor. It's an easy grab and go telescope.

[carolinaskies]

Hello, thank you for all the good comments. And is definitely solidified my thoughts around the 9 and 1/4 SCT. Although I truly love my refractors, I need a little bit more aperture to hopefully see more details on the planets. And the 9 and 1/4 in SCT is pretty lightweight also which is in its favor. It's an easy grab and go telescope.

LOL, you'll be pleasantly surprised at the difference the aperture brings to the table. 

[JohnH]

Maksutovs or something I've known having owned or currently owned four of them. They usually very usable without a lot of fussing, but they do need a bigger amount cuz they do tend to be heavier per inch than it Schmidt Cassegrain