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Meade 7" Mak...managing my expectations

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#1 ukcanuck

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Posted 23 November 2012 - 05:45 PM

I've always had a soft spot for this big Mak...long before I made my own refractors. Ever since I used to wander into Telescope House in London and check out the LX200 GPS version...and then Meade ended it.

I finally had a chance to pick up an LX50 version of this scope for a good price some time ago, and had a first chance to try it out...but, it didn't perform as well as I had hoped. So, I was left hoping it was the seeing holding it back and not my expectations.

I'm hoping this scope will be a good double star and planetary scope, it can live outside at ambient temperature, so hopefully I can keep the evil cool down time to an issue.

Seeing was far from perfect, but not too bad and my first look through this Maksutov (or any Maksutov of this size) showed some good detail in Jupiter, but I was disappointed on double stars...hence my request to have some feedback on my expectations. As I now use mainly refractors, is it reasonable to expect this LX50 Mak to hold it's own on double stars? :question:

Any thoughts would be appreciated. Thanks for reading.

#2 Robo-bob

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Posted 23 November 2012 - 05:50 PM

I had the LX200 version and it was just superb. It took a while to equilibriate but once there, it was just phenomenal on double stars and solar system. Never should have let it go.

#3 Spyke

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Posted 23 November 2012 - 06:25 PM

I must admit, Richard, I always drooled over the pics of those Meade 7" Maks too, usually in the adverts in S&T if I remember correctly!

I'm on my second 180mm Mak now (Orion USA version this time), and the Skymax I had a few years ago was a great performer on planets, but big Maks do perform differently than smaller long focal refractors. I'm sure an expert will advise soon enough, but I expect it has to do with energy and airy discs and things! so, the perfect view of a double star through a Mak will no doubt differ from the perfect view of the same star through a refractor.

At least, that's what I would think...

Ant :)

#4 Eddgie

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Posted 23 November 2012 - 07:00 PM

I guess the question that needs to be asked is in what way did it failto meet your expectation?

My guess is that it was due to the fact that stars did not present themselves as a clear Airy pattern???

If seeing was not fairly good then you got the result you could expect from any larger scope with a moderatly large central obstruction.

As an example, stars are rarely visible in my C14 as crisp Airy patterns, but I can just about always split stars in my C14 that are just out of reach of my 6" APO.

But the stars I that I can spit in my 6 " are almost always a "prettier" split in the 6". And on many nights, splits are not even "pretty" in the 6"APO.

Bottom line.. Because of seeing, the harder it becomes to get "pretty" splits with increases in aperture. But when seeing is excellent you can get beautiful splts even out of a C14.

Your chioce is to enjoy pretty splts from yourv small scopes, or tighter splits out of your larger scope with some occasional nights of pretty splits.

I do tight splts all the time but for me they don't need to be pretty, just split and now and again they are booth.

#5 Erik Bakker

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Posted 23 November 2012 - 07:03 PM

A Mak wil not show the superclean Airydisks with faint first ring like a good apo will. It can do very well on the moon and planets.

#6 orion61

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Posted 23 November 2012 - 09:25 PM

Do you have one of these Maks Eric?
I am on my 2nd 7" Meade, and it is a superb performer!
My first one was an LX50 and it wasn't as good as my 2nd one. I get very good airy disks and defraction rings with mine, I would say compairing the " Looks" of my defraction rings to my 102 APO the single defraction ring is slightly
thicker than the refractor but still very clean and exceeding pleasant to look at. The ficused images show a slight bit of contrast loss, but it is hardly worth mentioning except in all honesty.
This Mak has "in my opinion after 40 years of experience",
having optics tested and certified between 1/6th and 1/10th wave and learning what each perform to, would say is 1/9th wave, with a nice smooth surface and mostly identical inner and outer defraction patterns. I just sold an Intes mk66
with a 1/6th wave cert. and the Meade was very much sharper.
My first one was about 1/6th wave, certainly defraction limited, but the stellar images were not quite as clean,
There was a bit of light scatter in them.
It takes a fairly bad seeing condition before mine under performs.
It certainly beats my C6 Nexstar se hands down, the images snap into focus, backgrounds are inky black with exceptional contrast.
I would ask the OP if the system is collimated well?
There is a push/pull screw set on the Meade 7", mine was out a touch, it also suffered by quite a bit of image shift untill I relubed it with my own mixture of a thin layer of thick grease to take up then I mixed Super Lube and Mobile 1
synthetic oil for the top. there was a dramatic decrease in shift, and it stays aligned from one part of the sky to the next.
One problem people have is a small number of scopes sampled in compairing them, a large number of them being used scopes that in some cases, other peoples problem that get sold and re-sold due to ave performances.
I on the other hand service SCT scopes and have had a great chance to star test a lot of scopes. Believe me there is
a lot of difference from the best to worst commercial scopes out there. (I am a huge proponent of some sort of rating system for eack OTA) I applaud Intes for having the GUTS to do it on their Maks, and you do see a pricing difference.
I am exceedingly pleased with my 7" Mak. it is a heavy beast, but well worth it.
The system has received many compliments
from people of all experience levels, they are just a different beast. This one is mine... and going nowhere...

#7 Eddgie

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Posted 23 November 2012 - 11:11 PM

Even a scope with poor optical quality can show a clean Airy pattern if seeing is excellent, and that was my message.

And even if the optics are perfect, you will not see a clear Airy pattern unless seeing is excellent. This has nothing to do with the kind of telescope or the quality, only the seeing conditions and aperture.

The OP was using to much aperture for his seeing conditions, and that was my only point

#8 ukcanuck

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Posted 24 November 2012 - 04:14 PM

Thanks to everyone for your thoughts, they are much appreciated.

I now feel the issues are probably operator-related and my expectations now feel effectively managed. With this in mind, I look forward to my next night out with the Mak so that I can put it through my paces again... :cool:

#9 azure1961p

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Posted 24 November 2012 - 04:40 PM

Orion,

Erik used to own a Questar 7 before he got his Wirth reflector.

Pete

#10 orion61

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Posted 24 November 2012 - 05:10 PM

I honestly meant no insult, sorry it it sounded like that,
BUT I have had some pretty insensitive comments from Refractor guys who had No clue of what I had or had not looked through one.
I have both and MY 7" Mak gives surprisingly good images.
Same reason I don't spend a lot of time in Camera Forums,
its worse, talk about snobby.... Sorry Erik....

#11 Erik Bakker

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Posted 25 November 2012 - 06:16 AM

Orion,

Apology accepted :)

My Questar 7 was a bit sharper still than your 7" Meade. Yet even with essentially perfect optics, the large CO of the MCT makes itself known. My short answer about the airy disk is the condensation of many years at the eyepiece of my Q7 and 2"-6" apo's. Included is a pic of my Q7 and 4" Tak. As you can see, the Q7 beats the 4" in compactness. And I have enjoyed stunning views of the moon and planets with the Q7 :bow:

It got replaced by a scope with double the aperture, half the CO and similar quality optics :love:

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