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AP 10" Maksutov vs TEC 200 Fluorite apo

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#51 Max Lattanzi

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Posted 04 July 2012 - 03:15 PM

The 8" Mak has shown me detail on Ganymeade. I have never seen such a feature with the 180.


I have seen details on Ganymede (and Io) several times using a 180EDT. I would be really surprised if you cannot do the same with your 180FL. It *does* take a very-good to excellent night, though. It's a matter of seeing; a bit like the Pup. Probably you've been just unlucky on those nights with the 180FL. There's nothing wrong with your excellent refractor.

-- Max

#52 mark8888

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Posted 12 December 2012 - 02:50 AM

Jim,

While asking this, you are certainly aware that Roland keeps in his own observatory a 10” Mak and a 180EDT side by side. I recall him stating more than once that, only when seeing is approaching Pik 9, thus *very seldom*, his Mak delivers slightly better planetary performances than the nearby Apo. As soon as the air starts moving a bit, the Mak lies behind (his words). That’s the reason why he has been always keeping the 180EDT.


Hi... I'm reviving this kind of old thread because I found the above quote interesting. As a person who wasn't aware of that, I wonder if anyone happens to have a link to documentation about it, like a quote from the man himself? I'd be interested to read what he had to say about it verbatim. I did a search but couldn't find it.

ps wow 12/12/12! nice.

#53 Mel M

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Posted 12 December 2012 - 02:55 PM

Jim,

While asking this, you are certainly aware that Roland keeps in his own observatory a 10” Mak and a 180EDT side by side. I recall him stating more than once that, only when seeing is approaching Pik 9, thus *very seldom*, his Mak delivers slightly better planetary performances than the nearby Apo. As soon as the air starts moving a bit, the Mak lies behind (his words). That’s the reason why he has been always keeping the 180EDT.


Hi... I'm reviving this kind of old thread because I found the above quote interesting. As a person who wasn't aware of that, I wonder if anyone happens to have a link to documentation about it, like a quote from the man himself? I'd be interested to read what he had to say about it verbatim. I did a search but couldn't find it.

ps wow 12/12/12! nice.


He has said his refractors are best for imaging and that there are better choices for visual.

#54 Paul G

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Posted 12 December 2012 - 05:28 PM

Since his refractors are nulled at peak visual wavelength I'd be interested in seeing the context of his comment; given that and the minimum guaranteed Strehl of 0.984 it's hard to imagine another scope of similar aperture being a better visual instrument. His 10" Mak, for instance, was designed as a no-compromise visual lunar/planetary scope.

#55 maknewtnut

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Posted 12 December 2012 - 05:43 PM

It's just this sort of thread that could be referred to when the never ending threads about how a refractor will always be superior to any reflector pop up. An associated myth are claims that a refractor is equal to a reflector X number of inches larger.

Since these sort of arguments seem to pop up without end, I can't help but surmise that many folks have never seen what a superb reflector is capable of providing. For that matter, I believe it's likely many of the same folks have never observed with an apo triplet any larger than 5-6" either.

#56 ValeryD

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Posted 12 December 2012 - 05:48 PM

Since I have essentially the same 10" Mak and a very similar (in performance on planets) a 178mm Fluorite APO, I have to say that I slightly disagree with Roland's estimations.

1. Mak starts to outperform the 178mmm APO from the seeing of 7 out of 10, being slightly better at 6 out of 10.

2. At seeing 8 out of 10, the 10" Mak wins with serious gap without any doubts.

3. At seeing higher than 8 out of 10, Mak wins hands down.
No comparition.

#57 Mel M

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Posted 12 December 2012 - 06:23 PM

Since his refractors are nulled at peak visual wavelength I'd be interested in seeing the context of his comment; given that and the minimum guaranteed Strehl of 0.984 it's hard to imagine another scope of similar aperture being a better visual instrument. His 10" Mak, for instance, was designed as a no-compromise visual lunar/planetary scope.


The context was considering the cost of his refractors there were better options for visual use.

#58 Astrojensen

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Posted 12 December 2012 - 07:27 PM

If the cost, the mount or the size is not an issue, then, aperture for aperture, a refractor is best (within limits). If, however, any of these are an issue, you'll have to compromise. It's as simple as that, in my opinion.

Can you afford a 12" refractor? I can't. Can I afford a 12" newtonian? Yup! Are they equal? No, but there are worse alternatives: No scope at all!


Clear skies!
Thomas, Denmark

#59 Mel M

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Posted 12 December 2012 - 07:55 PM

If the cost, the mount or the size is not an issue, then, aperture for aperture, a refractor is best (within limits). If, however, any of these are an issue, you'll have to compromise. It's as simple as that, in my opinion.

Can you afford a 12" refractor? I can't. Can I afford a 12" newtonian? Yup! Are they equal? No, but there are worse alternatives: No scope at all!


Clear skies!
Thomas, Denmark


He has also said refractors larger than 7 or 8 inches have problems that make other options more attractive for visual use.

#60 azure1961p

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Posted 12 December 2012 - 08:01 PM

Buying is not the question. Let's say neither would sell for more than the other. You walk into a store and can walk out with one, no charge. Which would it be?


A couple years maybe.

Pete

#61 mgwhittle

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Posted 12 December 2012 - 08:15 PM

If the cost, the mount or the size is not an issue, then, aperture for aperture, a refractor is best (within limits). If, however, any of these are an issue, you'll have to compromise. It's as simple as that, in my opinion.

Can you afford a 12" refractor? I can't. Can I afford a 12" newtonian? Yup! Are they equal? No, but there are worse alternatives: No scope at all!


Clear skies!
Thomas, Denmark


He has also said refractors larger than 7 or 8 inches have problems that make other options more attractive for visual use.


Problems such as?

#62 azure1961p

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Posted 12 December 2012 - 08:17 PM

Theres a reason D. Peach lugs those heavy C14s all the way to Barbados during opposition. For imaging the extra 4" will win.

As to the op, its a tough one. For imaging Id go with the AP, for visual, the TEC. Letting go of that TEC is dicey, 8" chunks of fluorite are going the way of the dodo.


He also doesn't have an AP Mak-Cass.


Very true but post imaging processing would fly right past the AP10 images. Oh I'm sure the 10mak is dandy and probably the best in the world and I believe other c14 owners who give the visual nod to that Mak. But being that processing can manipulate contrasts with extreme efficiency that little contrast edge the mak might have had is left behind as wavelet sharpening brings out micro details only a 14" can access through angular resolution. I would suggest perusing some of the 180mm AP APO planetary images and it's clear even a ten inch f/4 newt is outdoing it.

Which one would I owner though - money no object. It'd be the Mak hands down. The c14 has that angular edge to be sure but in terms of visual contrasts and an aperture less needy of seeing than the 14 and the ten is king. The eight - any eight by ANYBODY- will never outdo a ten inch aperture in imaging. Visually it might do better in lesser seeing but don't we observe for those better nights?

Pete

#63 Ziggy943

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Posted 12 December 2012 - 08:31 PM

No doubt the AP 10" Mak is capable of superior performance on the Moon and planets over the TEC 200. Question is, in the field how often will that happen.

In my experience there are two components to the final "seeing." One is the atmosphere over which we have no control. The other is the thermal stabilization of the telescope. My experience with telescope thermal stability was with the 9" refractor an, by the time it was set up, it was ready to go. Not so with the 8" MAK. With very few exceptions it never reached equilibrium.

In my location it was my experience with a TEC 200 F/15 Mak that it reached it's planetary and double star potential 2 or 3 time in 4 years. Visually, side by side, the 160 class APO's outclassed it on Mars and double stars. That's why I made the decision to go with an APO refractor for myself. I'm not talking about just after set up, I mean for the observing session. My favorite double to judge the seeing is Epsilon Lyrae. I recall a friend shaking his head when looking through my 8" MAK. That hurt. OTOH, I had E-Lyrae at 400x in the MAK one night (literally one night) when seeing must have been perfect and had an image I can still see. On that night it was better than a 160 could be. Is that enough? It isn't for me.

I prefer the consistency of the refractor over the MAK in my location. If you live in an area where you have minimal nightime cooling the MAK may be a better choice.

When all is just right with the MAK it was the better scope but on run-of-the-mill nights the refractor is the better choice.

#64 Peter Natscher

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Posted 12 December 2012 - 11:08 PM

You don't now anything about the AP 10" Mak-Cass with your statements. Roland designed his 10" with a removable back cover exposing the primary mirror's backside, a primary mirror fan if needed, and a primary figured with aspheric curves for a flatter field and made of quartz. The two optical elements Mirror and corrector are 1/10 wave as is all of Roland's telescopes! Imagine that – 10 inches of 1/10th wave optics!! Who else is doing that? After the optics were bought from ARIES Optical, Roland was dissatisfied with their quality and totally refigured them to his high specs. Roland didn't make much money on these scopes after all of his extra work on them. Perhaps, this is why he dropped continuing the Mak-Cass production. This design quickens equilibration time and even allows great observing at moderate powers right after setting up outside before sunset. The 10" AP Mak-Cass is far superior in design to any other Cat. As you focus at any power. there is absolutely no mirror slop, either. Also, the Mak is not a reflector. It is a Cat.

No doubt the AP 10" Mak is capable of superior performance on the Moon and planets over the TEC 200. Question is, in the field how often will that happen.

In my experience there are two components to the final "seeing." One is the atmosphere over which we have no control. The other is the thermal stabilization of the telescope. My experience with telescope thermal stability was with the 9" refractor an, by the time it was set up, it was ready to go. Not so with the 8" MAK. With very few exceptions it never reached equilibrium.

In my location it was my experience with a TEC 200 F/15 Mak that it reached it's planetary and double star potential 2 or 3 time in 4 years. Visually, side by side, the 160 class APO's outclassed it on Mars and double stars. That's why I made the decision to go with an APO refractor for myself. I'm not talking about just after set up, I mean for the observing session. My favorite double to judge the seeing is Epsilon Lyrae. I recall a friend shaking his head when looking through my 8" MAK. That hurt. OTOH, I had E-Lyrae at 400x in the MAK one night (literally one night) when seeing must have been perfect and had an image I can still see. On that night it was better than a 160 could be. Is that enough? It isn't for me.

I prefer the consistency of the refractor over the MAK in my location. If you live in an area where you have minimal nightime cooling the MAK may be a better choice.

When all is just right with the MAK it was the better scope but on run-of-the-mill nights the refractor is the better choice.



#65 JJK

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Posted 13 December 2012 - 12:06 AM

You don't now anything about the AP 10" Mak-Cass with your statements. Roland designed his 10" with a removable back cover exposing the primary mirror's backside, a primary mirror fan if needed, and a primary figured with aspheric curves for a flatter field and made of quartz. The two optical elements Mirror and corrector are 1/10 wave as is all of Roland's telescopes! Imagine that – 10 inches of 1/10th wave optics!! Who else is doing that? After the optics were bought from AIRES Optical, Roland was dissatisfied with their quality and totally refigured them to his high specs. Roland didn't make much money on these scopes after all of his extra work on them. Perhaps, this is why he dropped continuing the Mak-Cass production. This design quickens equilibration time and even allows great observing at moderate powers right after setting up outside before sunset. The 10" AP Mak-Cass is far superior in design to any other Cat. As you focus at any power. there is absolutely no mirror slop, either. Also, the Mak is not a reflector. It is a Cat.

No doubt the AP 10" Mak is capable of superior performance on the Moon and planets over the TEC 200. Question is, in the field how often will that happen.

In my experience there are two components to the final "seeing." One is the atmosphere over which we have no control. The other is the thermal stabilization of the telescope. My experience with telescope thermal stability was with the 9" refractor an, by the time it was set up, it was ready to go. Not so with the 8" MAK. With very few exceptions it never reached equilibrium.

In my location it was my experience with a TEC 200 F/15 Mak that it reached it's planetary and double star potential 2 or 3 time in 4 years. Visually, side by side, the 160 class APO's outclassed it on Mars and double stars. That's why I made the decision to go with an APO refractor for myself. I'm not talking about just after set up, I mean for the observing session. My favorite double to judge the seeing is Epsilon Lyrae. I recall a friend shaking his head when looking through my 8" MAK. That hurt. OTOH, I had E-Lyrae at 400x in the MAK one night (literally one night) when seeing must have been perfect and had an image I can still see. On that night it was better than a 160 could be. Is that enough? It isn't for me.

I prefer the consistency of the refractor over the MAK in my location. If you live in an area where you have minimal nightime cooling the MAK may be a better choice.

When all is just right with the MAK it was the better scope but on run-of-the-mill nights the refractor is the better choice.


I agree with Peter. The AP 10" Mak-Cass's thermal management and mirror shift are well executed.

In addition, its optics are impressive. The scope can be pushed productively to far greater magnification than any SCT with which I've observed.

#66 M13 Observer

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Posted 13 December 2012 - 12:36 AM

If the cost, the mount or the size is not an issue, then, aperture for aperture, a refractor is best (within limits). If, however, any of these are an issue, you'll have to compromise. It's as simple as that, in my opinion.

Can you afford a 12" refractor? I can't. Can I afford a 12" newtonian? Yup! Are they equal? No, but there are worse alternatives: No scope at all!


Clear skies!
Thomas, Denmark


He has also said refractors larger than 7 or 8 inches have problems that make other options more attractive for visual use.


Problems such as?


9 plus inch refractors become bloody big and heavy. Not too many people have adequate mounting to support them. Not too many people have the equipment available to move them. They require serious dedication to even house in an observatory large enough. There are a few people who manage to do so, but they are rare indeed.

A well executed 10" such as the AP Mak is a total lightweight in a short manageable package in comparison to the 10" AP refractor Clint(sp) has. I shudder with the thought of even moving the pier he uses, never mind that monster mount and OTA!

#67 Astrojensen

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Posted 13 December 2012 - 03:29 AM

A well executed 10" such as the AP Mak is a total lightweight in a short manageable package in comparison to the 10" AP refractor Clint(sp) has. I shudder with the thought of even moving the pier he uses, never mind that monster mount and OTA!


Nevertheless, it's a dream of mine to one day own an 8" - 10" refractor (in a permanent observatory). A realistic dream, given my current income? No, but dreams are what they are.


Clear skies!
Thomas, Denmark

#68 RussD

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Posted 13 December 2012 - 11:12 AM

Mark,
You are right.

After many years of looking through high end refractors was convinced that APOs were the ultimate planetary scopes. I still consistently see 5-6 apos outperform reflectors of almost any size at a typical star party. But good reflectors that are collimated well are still pretty rare around here. But once I had the chance to spend some time with a really fine reflector, mostly my Lockwood figured 10", I realized that I was wrong. In good seeing etc, I have seen it easily outperform 6 and 7 inch APOs in side by side views on Jupiter. Have not been able to do side by side with larger refractors.

Now I am convinced the biggest drawback of reflectors is cool down issues and air currents. Something that refractors seem to handle a little better. But once things are cooled and the seeing is good, aperture will win out.

Russ

#69 maknewtnut

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Posted 13 December 2012 - 02:07 PM

Ziggy makes a good point too. Consistency in achieving potential performance may very be the most overlooked issue in scope selection (and discussion about it). One factor that often affects consistency is location. Those that live in high desert have to contend with far different ambient conditions than someone that lives on the coast. Detrimental effects from CO become exacerbated by less than ideal seeing conditions as well.


Case in point: all the folks who endlessly refer to Peach's planetary images as 'proof' of how good all C14's are.

There are too many factors to consider to lay down blanket statements.

#70 Ziggy943

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Posted 13 December 2012 - 02:21 PM

Peter, Your quote,

"Also, the Mak is not a reflector. It is a Cat."

Of course the Mak is a reflector. It has a primary mirror does it not? It's a more exotic reflector but it's still a reflector.

#71 TG

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Posted 13 December 2012 - 02:22 PM

The two optical elements Mirror and corrector are 1/10 wave as is all of Roland's telescopes! Imagine that – 10 inches of 1/10th wave optics!! Who else is doing that? After the optics were bought from ARIES Optical, Roland was dissatisfied with their quality and totally refigured them to his high specs. Roland didn't make much money on these scopes after all of his extra work on them. Perhaps, this is why he dropped continuing the Mak-Cass production.


The two optical elements have to be more than 1/10 wave corrected. 1/10 wave is what A-P guarantees is the wavefront quality at the eyepiece and being mirrors, both secondary and primary surfaces have to be figured to 1/20 wave. Roland's said he stopped making this design because it was a "female dog" :grin: to make with its aspheric curves.

While Roland put considerable thought into the cooling aspects of the scope, such as a rear-polished quartz primary, fans, removable backplate, etc., the fact remains that large scopes will have trouble catching up to ambient when it drops faster than the rate at which they can reasonably cool off. In the northern climes, especially when it's a bit dry, temperatures often keep dropping into the early morning. Any large scope, including the venerable A-P Mak, will have to wait till this time for optimum performance. FWIW, my 7" refractor performs optimally only at this time, not from its own cooldown problems but from the fact that the atmosphere had stabilized by then.

Tanveer.

#72 TG

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Posted 13 December 2012 - 02:26 PM

Buying is not the question. Let's say neither would sell for more than the other. You walk into a store and can walk out with one, no charge. Which would it be?


Without busting a spinal disk I doubt any of us codgers could actually walk out of a store with a 200mm refractor. :lol:

#73 Bowmoreman

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Posted 13 December 2012 - 04:22 PM

My weigh-in, with not anywhere near enough "samples" (especially on nights with good enough seeing)... Rating Jupiter views:

1. 12" Takahashi DK (my neighbors) - revelatory views
2. Close 2nd - my 10" f4.7(ish) Zambuto mirrored Dob
3. My C11
4. My TOA130
5. My FSQ106

Note the *almost* perfect correlation to aperture... with the 10" Zambuto reflector clearly beating the 11" C11, likely due to a) quality of optics and b) rather smaller central obstruction

As I'm not - yet - a planetary imager (though my friend/neighbor with the Tak M300 *is*) I can't / won't comment on that aspect...

So... I'd have to vote for the AP Mak... especially on "practicality" grounds

#74 Peter Natscher

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Posted 13 December 2012 - 04:43 PM

Also, the AP 10" Mak-Cass needs no collimation as other Cats and Cass'es do! – the secondary is not a separate mirror but a silvered area on the corrector (as Questars are).

The two optical elements Mirror and corrector are 1/10 wave as is all of Roland's telescopes! Imagine that – 10 inches of 1/10th wave optics!! Who else is doing that? After the optics were bought from ARIES Optical, Roland was dissatisfied with their quality and totally refigured them to his high specs. Roland didn't make much money on these scopes after all of his extra work on them. Perhaps, this is why he dropped continuing the Mak-Cass production.


The two optical elements have to be more than 1/10 wave corrected. 1/10 wave is what A-P guarantees is the wavefront quality at the eyepiece and being mirrors, both secondary and primary surfaces have to be figured to 1/20 wave. Roland's said he stopped making this design because it was a "female dog" :grin: to make with its aspheric curves.

While Roland put considerable thought into the cooling aspects of the scope, such as a rear-polished quartz primary, fans, removable backplate, etc., the fact remains that large scopes will have trouble catching up to ambient when it drops faster than the rate at which they can reasonably cool off. In the northern climes, especially when it's a bit dry, temperatures often keep dropping into the early morning. Any large scope, including the venerable A-P Mak, will have to wait till this time for optimum performance. FWIW, my 7" refractor performs optimally only at this time, not from its own cooldown problems but from the fact that the atmosphere had stabilized by then.

Tanveer.



#75 mark8888

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Posted 13 December 2012 - 07:24 PM

Peter, speaking of comparing large refractors and Maks, are you happy with your AP175, or is there something about it you wish were more AP Mak-like?


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