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Meade 7" Maksutov

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#26 donadani

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Posted 22 December 2017 - 08:42 AM

Hi Herman,

 

mine is from an LX200 too but it was "deforked" - that LX200 forkmount really is a hell of a beast ;) but should be rock stable and if you could permanent mount it for sure a great solution.

 

Hope without the counterweight the scope will fairly ride on a GP-DX - will check in the next days :)

 

cs

Chris



#27 Starman27

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Posted 22 December 2017 - 12:30 PM

I think you should be OK. W/O the counter weight it will weigh about as much as a Meade 8" CAT. The front end will be a little heavier.



#28 Live_Steam_Mad

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Posted 22 December 2017 - 03:36 PM

My Meade 7" Mak without internal weight is an very good match for my CG5. Damping times of around 1 second at 300x or so. Observations at 666x are easily possible. Focussing by hand is no problem. I have used it in this configuration hundreds of times.

 

Regards,

 

Alistair G.


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#29 donadani

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Posted 23 December 2017 - 07:00 AM

Got it! :)

 

The scope was well packed and made it save to it´s new home. First inspection looks good - only with strong LED flashlight I can see some sleeks on the meniskus. Would be interesting if this is with all scopes or selfmade with a wrong cleaning maybe? But however this has absolute none influence to the views for sure.

 

First views on daylight was great up to 450x but as it´s a grey and dark winter day the views getting very dark here - but looks like it´s a fine optics.

 

Now the only thing needed need is starlight!!! :)

 

 

DSC_0003.JPG

 

cs

Chris

 


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#30 donadani

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Posted 23 December 2017 - 07:01 AM

btw. these GSO rings fits PERFECT!!!! smile.gif

 

DSC_0004.JPG

 

 


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#31 Starman27

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Posted 23 December 2017 - 11:36 AM

You will definitely enjoy this scope. Can't wait for your first light report. What size are the GSO rings?



#32 donadani

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Posted 23 December 2017 - 12:53 PM

Looking for a clear sky too wink.gif the first tests were very promissing!

 

As the scope came without rings, rail and rearside adapter I ordered these rings from TS new: https://www.teleskop...en-D-230mm.html

 

...and hoped they´ll fit - luckily they did and perfect!

 

Rail and Baader rear-end with 1,25" prism I had over from my long gone C9,25 - so the setup was completed. The GP-DX seems to be a perfect match for that scope.

 

Focus shifting at high mags is very little - but I prefere to finefocusing with a Baader 1,25" helical eyepiece-adapter at the prism - that is really fine.

 

cs

Chris 

 

DSC_0002.JPG


Edited by donadani, 23 December 2017 - 01:43 PM.

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#33 Ptkacik

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Posted 23 December 2017 - 09:15 PM

That scope makes for a beautiful package.

Clear skies and Merry Christmas,
Peter

#34 Erik Bakker

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Posted 24 December 2017 - 07:40 AM

I find any great Maksutov a thing of beauty. Looks lovely, that Meade 7" Mak.


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#35 donadani

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Posted 24 December 2017 - 08:34 AM

btw. scope ready for use (including all) is 9kg...

 

weight.jpg

 

 

...and as it is a short package the DX can easy handle it.

 


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#36 REC

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Posted 26 December 2017 - 02:48 PM

I have two Mak 7's; one from LX50 production and the other from LX200 production. Both have had the weight removed and both give the sharpest image that I have ever seen in a production scope. Given the exceptional image quality I'd be hesitant to fiddle with the secondary baffle. If nothing else it keeps light from entering the primary baffle from around the secondary. If it t'ain't broke...

 

A Mak 7 in good condition for $400ish is very attractive. I paid a fair amount more than that for mine 'cause I wanted one. I ended up with two so that I could configure one for visual and the other for imaging.

 

My baby....

 

attachicon.gifLX90 Mak 7 (7-23-2017)-1.jpg

 

...an LX200 Mak 7 on an LX90 configured for visual. With the weight removed the built-in fan acclimates the scope very quickly.

 

Good luck!

I worked for Meade in 1998 and I would drool over that scope! I never got a chance to look through it at the sky, but is was sure a beautiful looking scope. Besides, my favorite color is blue. I still have the 90 and 125 ETX, but don't use them that much. Maybe I'll take the 125 out tonight for the moon, the poor thing hasn't been out much in a long time!


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#37 Daniel Mounsey

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Posted 30 December 2017 - 04:22 AM

Meade 7" Maks were some of the best Maks I ever tested. Absolutely loved them. I asked Meade about bringing them back but I doubt that will happen.


Edited by Daniel Mounsey, 30 December 2017 - 04:26 AM.


#38 payner

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Posted 30 December 2017 - 12:46 PM

I have one and it has a long history with my observing habits.  It has optics that I think are about the best in consistency across the model line then many other catadioptric telescopes.  It commanded a higher price than the 8" SCTs when available new, but it may be an example where a higher unit cost went toward better, and more uniform, optics.

 

Randy



#39 Asbytec

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Posted 30 December 2017 - 10:22 PM

I have one and it has a long history with my observing habits.  It has optics that I think are about the best in consistency across the model line then many other catadioptric telescopes.  It commanded a higher price than the 8" SCTs when available new, but it may be an example where a higher unit cost went toward better, and more uniform, optics.

 

Randy

Not to derail the thread, but I suspect many commercial MCTs are the same. The Meade has a great reputation, so does Orion and Skywatcher, among others. I love my (non Meade) MCT. I tend to think there is something amazing about the design itself. That something may be smooth, more uniform optics. Easy to make, no, but easier to make smooth maybe. I really got into lunar and planetary observe like no other time, and not bad on deep sky, either. 


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#40 donadani

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Posted 31 December 2017 - 04:50 AM

Hi guys,

 

cloudy and rainy all the time - weather didn´t allowed a real startest right now - but tried a bit at daylight objects. When the scope is cooled after about 45-60min (without fans) views up to 700x seems to be very sharp. I couldn´t detect any mentionable mirror shifting when changing the focusing direction - just at this magnification objects in the center travel only very little - very nice!

 

The focuser works nice but anyway I´m thinking about change it against a Feather Touch one... - I just deassambled the present one - but was not able to take it out completely - it alway hangs on the shaft inside and I couldn´t bring it far enough to the outer side that it comes out... is there any trick?

 

cs

Chris



#41 donadani

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Posted 31 December 2017 - 01:12 PM

Meade 7" Maks were some of the best Maks I ever tested. Absolutely loved them. I asked Meade about bringing them back but I doubt that will happen.

Could make a startest before some minutes ...and it looks like this one is no exception :) :) :) more tomorrow...

 

Have a good start in 2018!

 

cs

Chris



#42 Mitrovarr

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Posted 31 December 2017 - 01:58 PM


I have one and it has a long history with my observing habits. It has optics that I think are about the best in consistency across the model line then many other catadioptric telescopes. It commanded a higher price than the 8" SCTs when available new, but it may be an example where a higher unit cost went toward better, and more uniform, optics.

Randy

Not to derail the thread, but I suspect many commercial MCTs are the same. The Meade has a great reputation, so does Orion and Skywatcher, among others. I love my (non Meade) MCT. I tend to think there is something amazing about the design itself. That something may be smooth, more uniform optics. Easy to make, no, but easier to make smooth maybe. I really got into lunar and planetary observe like no other time, and not bad on deep sky, either.

Every surface in a Gregory mak is spherical. This means that they are particularly easy to machine-fabricate well. I would guess this has a lot to do with why they're so inexpensive (in small apertures) and good these days.

Some of the really fancy maks diverge from this and have some non-spherical surfaces (the AP and the Questar, I hear) and thus have better correction. But they have enough money put into them to hand-figure those surfaces well.

#43 vahe

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Posted 31 December 2017 - 03:43 PM


Every surface in a Gregory mak is spherical. This means that they are particularly easy to machine-fabricate well. I would guess this has a lot to do with why they're so inexpensive (in small apertures) and good these days.

Some of the really fancy maks diverge from this and have some non-spherical surfaces (the AP and the Questar, I hear) and thus have better correction. But they have enough money put into them to hand-figure those surfaces well.

 

 

Here is what Roland had to say about 7” Meade Maksutov in a post discussing various Maksutovs in ap-ug:

"Interestingly, the 7” Meade is a form of aspheric Gregory. Unfortunately they chose to make a huge secondary obstruction > 35%. I believe they achieved the aspheric surface by deforming the primary during polishing. The main problem that I see with that approach is that it is almost inevitable that some astigmatism will result in the primary figure. It is more straight forward to make a Mak with separate secondary and all surfaces spherical."

 

Vahe



#44 Mitrovarr

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Posted 31 December 2017 - 05:57 PM

Thay would explain why the Meade 7" is almost universally regarded as being amazing optically, and the modern standard 180mm Orion/SW Mak doesn't share quite that level of reputation. Meade must have either found some way around that problem Roland describes, or it is not that bad (Roland is well known to be quite perfectionist).
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#45 Asbytec

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Posted 01 January 2018 - 07:20 AM

Thay would explain why the Meade 7" is almost universally regarded as being amazing optically, and the modern standard 180mm Orion/SW Mak doesn't share quite that level of reputation. Meade must have either found some way around that problem Roland describes, or it is not that bad (Roland is well known to be quite perfectionist).

As I recall, Frank (Freestar) mentioned that most commercial Gregory Maks almost require an asphere at available apertures and focal ratios for 'acceptable performance' over an all spherical system. Going off memory, I believe Meade even advertises it's elliptical primary. So, we presumed most commercial Maks also achieve an aspheric primary similar to Meade, but do not seem to advertise whether they do or not. We've bantered this around a few times, but no one knows for sure. 

 

Here's what Vlad has to say. "While it varies somewhat with the specifics of corrector, acceptable optical quality in this respect doesn't extend significantly beyond a 6" ƒ/3 primary level. Another option is to have the primary aspherised, which allows for weaker corrector, with reduced higher-order spherical aberration."

http://www.telescope...n_telescope.htm

 

I can say I have been impressed with mine (non Meade.) They also did somethign right. I've been upwards of 70x per inch on Mars with some of the best views ever of that planet in excellent tropic seeing, cooled to ambient, and well collimated. Star testing shows pretty good correction, IMO. Not perfect, but certainly better than 1/4 PV LSA. Not bad for an "all spherical" with highly curved surfaces including a fast mirror.

 

That's the basis of my claim. I cannot compare with the Meade, which may well be better. Again, in discussions a few years ago, we presumed other commercial Maks were using an asphere, as well, because they almost have to. I dunno, you tell me. We'd love to know one way or another if the elliptical primary is more readily available on other commercial Maks. Not just the Meade. If so,  then performance should be similar in both models...which is a good thing, these are nice scopes. 


Edited by Asbytec, 01 January 2018 - 07:21 AM.


#46 donadani

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Posted 01 January 2018 - 07:40 AM

HAPPY NEW YEAR TO EVERYBODY!!!

 

After a long time of clouds and rain - yesterday was the first day since a while with a clear sky... - of course yesterday! just the evening everybody has other plans then startesting a new scope wink.gif

 

1.jpg

 

 

When I tried the startest first time before some days I only had a small hole in the sky and brought the scope out from a warm living room to the cold night (23°C to about 2°C). Startest at this state was terrible and showed a strong spherical error (no more sure if it was over- or undercorrection) - dissapointing at first - but I hoped the correction would get better when the scope acclimates. A next proof 30min later showed just a better view but as always in such a case - after that it became cloudy again...

 

However, yesterday before we went out - I had the chance to do some better testing... so what did I find?

 

1. the scope just works very well on a lighter Great Polaris mount and don´t need the DX version - great!

 

2. the socpe really needs its time to cool properly to show it´s great optics (took it out about 1,5h before watching without using the fans)

 

3. when cooled - startest is near perfect - just as good as I found it with my earlier ETX90 and ETX125. This means identical looking ring patterns intra- and extrafokal at mags up to 650x and a clearly visible airydisc with diffraction ring. 

 

4. at highest magnifications I could see a very, very slight triangular astigmatism when looking at the first diffraction ring around the ariydisc. It looked like the ring has three slight light-breakaouts symmetrical at 120°. As its absolute symmetrical I guess it´s from the fixture screws of the meniskus lens that are maybe a bit too strong. But as it´s so minor it will not have any effect at "normal" use and I´m confident it could be completely removed with a little bit optimization.

 

5. mirror shifting while focussing is so small it really is negligible - just at 650x you have to look very keenly for it to find a very slight moving of the image when changing the focusing direction - no comparrision to my earlier C9,25 from which I just thought it was good at this point.

 

6. just with the secondary baffle installed I got some ugly reflexions when looking at objects close to the moon - but that was for testing only and should be normal.

 

 

2.jpg

 

3.jpg

 

 

So I´m very happy with this buy - incredible how much scope you can get for a very reasonable price! Looking forward to do some comparrisons with this scope against some 5" and 6" apos... 

 

cs

Chris

 

 


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#47 freestar8n

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Posted 01 January 2018 - 08:07 AM

As I recall, Frank (Freestar) mentioned that most commercial Gregory Maks almost require an asphere at available apertures and focal ratios for 'acceptable performance' over an all spherical system. Going off memory, I believe Meade even advertises it's elliptical primary. So, we presumed most commercial Maks also achieve an aspheric primary similar to Meade, but do not seem to advertise whether they do or not. We've bantered this around a few times, but no one knows for sure.

I own a meade mak 7 from the late 90's and I don't think they advertise it as asphere, but the manual says it is - and I confirmed it with a Foucault test of the primary.

 

The Gregory 6" f/15 also required aspherization.  In fact - any mak that was made by final figuring in an autocollimator is aspherical - since final departures from sphere were required to compensate for errors in the system.

 

The bigger they are and the faster they are - the more they need an asphere - especially if the meniscus is thin.

 

There is a whole gray area between a spherical spot Maksutov and a Dall Kirkham - with the meniscus getting thinner and the primary getting more ellipsoidal.

 

The main thing the design is battling is spherical aberration - and a good way to reduce its impact is either by blocking off the outer part of the aperture - or using a large secondary obstruction - which the Meade has.

 

The Maksutov design is odd because so many people expect it to be an amazing performer because it is made from "simple" spherical surfaces and has a small obstruction.  And in the case of the Meade - it also has a fan for rapid cooldown.  But in reality, the surfaces aren't spherical, the obstruction is large, and in most there is a giant hunk of metal blocking the fan.

 

This doesn't mean they will perform badly - it just means a lot of the reasons people think they should do well just don't apply.

 

I found mine to be decent and diffraction limited - but that meant when I switched to C11 - with larger aperture and the same focal length - and also  diffraction limited - I had more light and better detail.

 

I have removed the metal and re-coated the secondary - but have never been able to use it since it is at a different location.  I look forward to trying it out again.

 

Frank


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#48 dweller25

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Posted 01 January 2018 - 08:37 AM

Got it! smile.gif

 

The scope was well packed and made it save to it´s new home. First inspection looks good - only with strong LED flashlight I can see some sleeks on the meniskus. Would be interesting if this is with all scopes or selfmade with a wrong cleaning maybe? But however this has absolute none influence to the views for sure.

 

First views on daylight was great up to 450x but as it´s a grey and dark winter day the views getting very dark here - but looks like it´s a fine optics.

 

Now the only thing needed need is starlight!!! smile.gif

 

 

attachicon.gifDSC_0003.JPG

 

cs

Chris

That's a very nice 7" Mak,

Here's my Russian version....

IM715.jpg


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#49 donadani

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Posted 01 January 2018 - 08:59 AM

Hi David,

 

nice - thanks for sharing! is it a 715 or 703? 

 

Thought about one of these too as actually there´s one of each offered on the "local") used market - but prices are "a little bit" higher for these - the 703 is at 1.500 EUR (old version without fans!) and the 715 at 1.990,- when this Meade came up for sale it seems to be a bargain and I´m very happy the optics is a good one :)

 

cs

Chris



#50 donadani

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Posted 01 January 2018 - 09:05 AM

btw. found a nice picture showing what I saw yesterday evening reg. the triangular asti (the upper one): http://rohr.aiax.de/Alt_M809-12.jpg




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