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Classic 8" LX200 DPAC

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#1 rolo

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Posted 25 February 2018 - 04:43 PM

Here's the first Meade LX200 that I DPAC. Despite a bit of roughness, SA and a bit of a turned edge the scope gives very good views. I would say its one of the better Meade SCT's that I've star tested as well.

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#2 starman876

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Posted 25 February 2018 - 04:49 PM

that is very good for an SCT.



#3 Jim Waters

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Posted 25 February 2018 - 05:27 PM

I am glad it gives good images...  The tests look terrible.  Is this typical of Schmidt-Cassegrain scopes?

 

Just curious - can Schmidt-Cassegrain mirrors be refigured?



#4 CHASLX200

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Posted 25 February 2018 - 05:38 PM

I am glad it gives good images...  The tests look terrible.  Is this typical of Schmidt-Cassegrain scopes?

 

Just curious - can Schmidt-Cassegrain mirrors be refigured?

Most SCT's optics i have seen have been so so at best and some so bad, and then a few that were very good to super. They vary big time. Meade was at the top of it's game in the mid 90's with the award winning LX200. I had eight LX200's.  Had two very good 10" LX200's one very good 12" and one 12" was soft.  Had two very good 8" LX200's and two that were ok to good.  All of my LX200's were made in the mid and later 90's.

 

I had way more bad Orange Celestron SCT's on avg.  My best ever SCT was a black 1984 C8 that could do 500x and keep trucken.  Just picked up a a1976 C5 that is also super and does 400x no prob.  I am sure you could pay a top mirror maker to make it Zambuto good, but at  a very high price.

 

The sad fact is, SCT's are all over the map. Don't matter what year they were made as there were insane sharp killers and total mush dogs.



#5 starman876

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Posted 25 February 2018 - 05:44 PM

sounds like most commercial mass produced optics.



#6 davidc135

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Posted 25 February 2018 - 05:52 PM

I am glad it gives good images...  The tests look terrible.  Is this typical of Schmidt-Cassegrain scopes?

 

Just curious - can Schmidt-Cassegrain mirrors be refigured?

The problems are likely to be in the hard to figure corrector plates which have complex profiles.

 

David


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#7 rolo

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Posted 25 February 2018 - 06:25 PM

I am glad it gives good images...  The tests look terrible.  Is this typical of Schmidt-Cassegrain scopes?

 

Just curious - can Schmidt-Cassegrain mirrors be refigured?

No this is horrible... A Criterion Dynamax 8. This Meade compares favorably with other DPAC tested SCT's  that I've seen on line and come in at 1/4 to 1/5 wave with an interferometry test.

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#8 CHASLX200

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Posted 25 February 2018 - 06:34 PM

sounds like most commercial mass produced optics.

Yep. Can't expect Zambuto like optics at the price point they sell for.



#9 bob midiri

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Posted 25 February 2018 - 06:42 PM

Those optics on that Meade tests pretty good for a mass produced system of that complexity,  at that price range...I would certainly be happy with that particular scope , nice o e Rolo...now test your Tri color 


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#10 CHASLX200

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Posted 25 February 2018 - 06:43 PM

Those optics on that Meade tests pretty good for a mass produced system of that complexity,  at that price range...I would certainly be happy with that particular scope , nice o e Rolo...now test your Tri color 

Or that super C14.



#11 starman876

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Posted 25 February 2018 - 06:50 PM

 

sounds like most commercial mass produced optics.

Yep. Can't expect Zambuto like optics at the price point they sell for.

 

well those are only a primary and  flat secondary in most cases.  A bit easier to make good optics when you only need to worry about two surfaces.  The SCT is a lot more complex, therefore, like you stated by anyones standards to get excellent optics in a multi surface scope like an SCT you would have to spend a lot of cash.  Would love to DPAC that Tac 225 on amart.



#12 CHASLX200

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Posted 25 February 2018 - 06:55 PM

 

 

sounds like most commercial mass produced optics.

Yep. Can't expect Zambuto like optics at the price point they sell for.

 

well those are only a primary and  flat secondary in most cases.  A bit easier to make good optics when you only need to worry about two surfaces.  The SCT is a lot more complex, therefore, like you stated by anyones standards to get excellent optics in a multi surface scope like an SCT you would have to spend a lot of cash.  Would love to DPAC that Tac 225 on amart.

 

I am sure the Tak would be good on the DPAC jack.



#13 DAVIDG

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Posted 25 February 2018 - 06:58 PM

 The idea behind a commeric

 

 

 

 

sounds like most commercial mass produced optics.

Yep. Can't expect Zambuto like optics at the price point they sell for.

 

well those are only a primary and  flat secondary in most cases.  A bit easier to make good optics when you only need to worry about two surfaces.  The SCT is a lot more complex, therefore, like you stated by anyones standards to get excellent optics in a multi surface scope like an SCT you would have to spend a lot of cash.  Would love to DPAC that Tac 225 on amart.

 

I am sure the Tak would be good on the DPAC jack.

 

 You never know until to  you get  it on the test stand and  check. It is  a used scope and you never know what could have happened to it. 

 

                   - Dave 


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#14 bob midiri

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Posted 25 February 2018 - 07:10 PM

 The idea behind a commeric

 

 

 

 

sounds like most commercial mass produced optics.

Yep. Can't expect Zambuto like optics at the price point they sell for.

 

well those are only a primary and  flat secondary in most cases.  A bit easier to make good optics when you only need to worry about two surfaces.  The SCT is a lot more complex, therefore, like you stated by anyones standards to get excellent optics in a multi surface scope like an SCT you would have to spend a lot of cash.  Would love to DPAC that Tac 225 on amart.

 

I am sure the Tak would be good on the DPAC jack.

 

 You never know until to  you get  it on the test stand and  check. It is  a used scope and you never know what could have happened to it. 

 

                   - Dave 

Hey Dave after my hockey season is finally over in 4 weeks, maybe we can meet at MT Cuba and DPAC that C14, with the original corrector. Bob



#15 rolo

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Posted 25 February 2018 - 07:11 PM

Those optics on that Meade tests pretty good for a mass produced system of that complexity,  at that price range...I would certainly be happy with that particular scope , nice o e Rolo...now test your Tri color 

Most folks don't understand that an SCT will not test as smooth as a refractor and it doesn't have  to be perfectly straight smooth lines to be an acceptable 1/4 wave. Newtonians usually test the primary and not the complete scope like the SCT so you don't see the complete picture. Also, the DPAC doubles all defects as opposed to a regular Ronchi test. I've seen some SCT tests on line that have worse Ronchi line results and interferometer shows better than 1/4 wave. All you need is 1/4 wave to have an acceptable optic, anything else is icing on the cake. 


Edited by rolo, 25 February 2018 - 07:13 PM.

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#16 rolo

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Posted 25 February 2018 - 07:59 PM

 

I am glad it gives good images...  The tests look terrible.  Is this typical of Schmidt-Cassegrain scopes?

 

Just curious - can Schmidt-Cassegrain mirrors be refigured?

 

 Just picked up a a1976 C5 that is also super and does 400x no prob.

 

I'll be testing a couple of C5's next month I expect similar results. I'll be glad to test your C5 OTA and I'll even pay the return shipping...


Edited by rolo, 25 February 2018 - 08:03 PM.

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#17 starman876

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Posted 25 February 2018 - 09:15 PM

 

 

I am glad it gives good images...  The tests look terrible.  Is this typical of Schmidt-Cassegrain scopes?

 

Just curious - can Schmidt-Cassegrain mirrors be refigured?

 

 Just picked up a a1976 C5 that is also super and does 400x no prob.

 

I'll be testing a couple of C5's next month I expect similar results. I'll be glad to test your C5 OTA and I'll even pay the return shipping...

 

Hard to pass that deal up.  Go for itwaytogo.gif



#18 CHASLX200

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Posted 26 February 2018 - 06:30 AM

 

 

 

I am glad it gives good images...  The tests look terrible.  Is this typical of Schmidt-Cassegrain scopes?

 

Just curious - can Schmidt-Cassegrain mirrors be refigured?

 

 Just picked up a a1976 C5 that is also super and does 400x no prob.

 

I'll be testing a couple of C5's next month I expect similar results. I'll be glad to test your C5 OTA and I'll even pay the return shipping...

 

Hard to pass that deal up.  Go for itwaytogo.gif

 

Never take a chance on shipping.



#19 bremms

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Posted 26 February 2018 - 08:23 AM

Here's the first Meade LX200 that I DPAC. Despite a bit of roughness, SA and a bit of a turned edge the scope gives very good views. I would say its one of the better Meade SCT's that I've star tested as well.

That looks good for an SCT.


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#20 bremms

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Posted 26 February 2018 - 08:25 AM

 

I am glad it gives good images...  The tests look terrible.  Is this typical of Schmidt-Cassegrain scopes?

 

Just curious - can Schmidt-Cassegrain mirrors be refigured?

No this is horrible... A Criterion Dynamax 8. This Meade compares favorably with other DPAC tested SCT's  that I've seen on line and come in at 1/4 to 1/5 wave with an interferometry test.

 

Wavy Gravy.... The Dynamax is an order of magnitude worse.


Edited by bremms, 26 February 2018 - 08:27 AM.

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#21 rolo

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Posted 01 March 2018 - 09:43 AM

that is very good for an SCT.

Indeed. I've seen worse DPACs on some refractors and Newts...




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