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Equipment Discussions >> Refractors

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Jon Isaacs
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Reged: 06/16/04

Loc: San Diego and Boulevard, CA
Re: Astro-Physics the Best Brand? new [Re: mikey cee]
      #6070786 - 09/09/13 07:31 AM

Quote:

Quote:



Rich people think differently than most other people do.


You got that right. That's exactly why the average millionaire drives a vehicle that is 11 years old. They get that way by a different set of values than the rest do. Mike




Gee, my wife and I must be an average millionaires.. My wife's car is 1999, my truck is 2004.. We've had the car for 2 years, it replaced 1996 that was totaled while parked. The truck, less than a year, it replaced a 2003 that was totaled while parked.

Jon


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rockethead26
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Reged: 10/21/09

Loc: Arizona, USA
Re: Astro-Physics the Best Brand? new [Re: Jon Isaacs]
      #6070796 - 09/09/13 07:43 AM

Quote:

Quote:

Quote:



Rich people think differently than most other people do.


You got that right. That's exactly why the average millionaire drives a vehicle that is 11 years old. They get that way by a different set of values than the rest do. Mike




Gee, my wife and I must be an average millionaires.. My wife's car is 1999, my truck is 2004.. We've had the car for 2 years, it replaced 1996 that was totaled while parked. The truck, less than a year, it replaced a 2003 that was totaled while parked.

Jon




Where the heck do you park?


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Eddgie
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Reged: 02/01/06

Re: Astro-Physics the Best Brand? new [Re: Rinaldo]
      #6070866 - 09/09/13 09:05 AM

Quote:

This statement is too general and can be interpreted that it doesn't perform as well visually




Well, nowhere did I ever say the scope will not perform well visually. You won't beat it with any same size aperture scope made.

But you can do as well for visual use because visual use is not as demanding as wide field imaging. The eye simply is not a sensitive enough detector to see the difference between an AP lens and many others at the extreme off axis.

But the CCD chip can.

And once again, the OP asks if AP is the best.

And the answer is that as a visual instrument, it can be matched, but as an astrograph, it can't be.

For somoene that wants to only use it visually, to wait 10 years to get one is kind of a gigantic waste of time.

To wait that long to get one only to put an eyepeice in it is a real waste of a decade.

That pretty much mirrors the conversation I had with Roland Christen about the topic. He pretty much in no uncertian terms told me that there were better choices for visual use, and that the real reason for waiting 10 years for a big AP was to get the best astrograph money can buy.

And I beleived him. Took my name off the list, bought a used AP triplet for visual use, and never looked back.
But I love my 6" AP. Oh, for planets, I use my C14, but for wide field viewing, the AP is amazing. No scope I have ever owned has provided me with the absolute perfection of field over two degrees that the AP can do. There is no visible coma, no visable field curvature, and no illumination dropoff.

For wide field viewing, nothing has ever come close to the AP 6".

And by the way, that is what makes them outstanding astrographs. Hmmmm.


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David PavlichAdministrator
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Reged: 05/18/05

Loc: Mandeville, LA USA
Re: Astro-Physics the Best Brand? new [Re: Eddgie]
      #6071043 - 09/09/13 11:08 AM

Question: Since I've never imaged with an AP but did use a couple other triplet refractors (TEC, Tak), there was a need for at least a flattener due to field curvature. Am I to assume that, say, an AP 130 needs a flattener, especially for chips like the 11000 or 16803 class? If so, then, while the optics are color free, there are other considerations when imaging with an AP triplet.

For wide field imaging, I've seen some very impressive results with Televue's 127is and Tak's FSQ106. Different designs for sure, but no need to introduce a flattener into the imaging train.

David


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HunterofPhotons
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Reged: 04/26/08

Loc: Rhode Island, USA
Re: Astro-Physics the Best Brand? new [Re: David Pavlich]
      #6071125 - 09/09/13 11:43 AM

Quote:

...For wide field imaging, I've seen some very impressive results with Televue's 127is and Tak's FSQ106. Different designs for sure, but no need to introduce a flattener into the imaging train.

David




Those are both Petzval designs, David.
They already have the flattener integrated into the design. <g>
Yes, an AP triplet will benefit from a flattener for a large-chip camera.

dan k.


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M13 Observer
scholastic sledgehammer


Reged: 12/09/06

Re: Astro-Physics the Best Brand? new [Re: David Pavlich]
      #6071129 - 09/09/13 11:43 AM

Quote:

Question: Since I've never imaged with an AP but did use a couple other triplet refractors (TEC, Tak), there was a need for at least a flattener due to field curvature. Am I to assume that, say, an AP 130 needs a flattener, especially for chips like the 11000 or 16803 class? If so, then, while the optics are color free, there are other considerations when imaging with an AP triplet.

For wide field imaging, I've seen some very impressive results with Televue's 127is and Tak's FSQ106. Different designs for sure, but no need to introduce a flattener into the imaging train.

David




The TV and the Tak you mention are Petzval's. Bottom line is that they are 4 element scopes with the elements in 2 groups, one big set at the objective end, and one small set at the eyepiece/ccd end. The ones at the eyepiece/CCD end act like a fancy field flattener and corrector for the objective elements. Yes the AP130 at f/6 definitely, and I can only assume, the AP130GT at f/6.3, require a field flattener with the wider/larger format CCD chips.


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bobmcg
member


Reged: 09/18/07

Re: Astro-Physics the Best Brand? new [Re: Eddgie]
      #6071165 - 09/09/13 11:59 AM

The wait doesn't have to be a waste of time. You can buy a different fine refractor to use while you are waiting then, when your AP comes, sell the "inferior" scope and use the money to help pay for the AP

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Bill McNeal
sage


Reged: 10/07/07

Re: Astro-Physics the Best Brand? new [Re: bobmcg]
      #6071188 - 09/09/13 12:09 PM

That's a good point--I didn't know Roland was that old and that new signups to the wait list are in danger of his possible retirement. That raises some questions for people considering getting on a wait list that may take years or decades:

1) Has Roland given any indication that he's retiring soon?

2) When he does, is there an heir apparent, an apprentice that will take over for him, or will AP just go out of business? I'm assuming he makes AP's mounts as well.

3) How do the remaining brands do for resale, like TEC vs. TeleVue vs. Tak? Or are they all pretty much the same?


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Jon Isaacs
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Reged: 06/16/04

Loc: San Diego and Boulevard, CA
Re: Astro-Physics the Best Brand? new [Re: HunterofPhotons]
      #6071196 - 09/09/13 12:13 PM

Quote:

Quote:

...For wide field imaging, I've seen some very impressive results with Televue's 127is and Tak's FSQ106. Different designs for sure, but no need to introduce a flattener into the imaging train.

David




Those are both Petzval designs, David.
They already have the flattener integrated into the design. <g>
Yes, an AP triplet will benefit from a flattener for a large-chip camera.

dan k.




A-P makes flatteners for their refractors, it's part of the package. The advantage of the modified Petzvals like the NP-101 is that they can be used visually whereas add on flatteners use up too much back focus. Otherwise, photographic flatteners provide more options for a particular scope.

I like my NP-101 but I have to think that if I had the chance to trade it straight across for a Traveler, I would jump on it.

Jon


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Jeff Morgan
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Reged: 09/28/03

Loc: Prescott, AZ
Re: Astro-Physics the Best Brand? new [Re: Bill McNeal]
      #6071253 - 09/09/13 12:39 PM

Quote:

That's a good point--I didn't know Roland was that old and that new signups to the wait list are in danger of his possible retirement. That raises some questions for people considering getting on a wait list that may take years or decades:

1) Has Roland given any indication that he's retiring soon?

2) When he does, is there an heir apparent, an apprentice that will take over for him, or will AP just go out of business? I'm assuming he makes AP's mounts as well.

3) How do the remaining brands do for resale, like TEC vs. TeleVue vs. Tak? Or are they all pretty much the same?





Roland appears to love what he does, so he'll likely go on as long as able. My father is one of those people and just retired (grudgingly) at age 86.

But many maladies of age don't give long range indications do they? Could be tomorrow, or RC could go beyond 100.

It's interesting to see how Tele Vue has handled the succession issue - namely bringing forth a new designer as the creator of the Ethos line. AFAIK from an optical perspective, AP appears to be a one-man show.

When Roland leaves the optical shop for the last time here will be no more true Christen lenses produced. On that day AP resale values will probably jump 10% or more. Then the ravages of time and accidents will take their toll on the existing population of AP scopes. As that population shrinks resale will continue to go up.


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David PavlichAdministrator
Transmographied
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Reged: 05/18/05

Loc: Mandeville, LA USA
Re: Astro-Physics the Best Brand? new [Re: HunterofPhotons]
      #6071342 - 09/09/13 01:34 PM

Quote:

Quote:

...For wide field imaging, I've seen some very impressive results with Televue's 127is and Tak's FSQ106. Different designs for sure, but no need to introduce a flattener into the imaging train.

David




Those are both Petzval designs, David.
They already have the flattener integrated into the design. <g>
Yes, an AP triplet will benefit from a flattener for a large-chip camera.

dan k.




Yep...you'll note that I did mention that the 106 and 127 are different designs. And I quote from my own post:

"For wide field imaging, I've seen some very impressive results with Televue's 127is and Tak's FSQ106. Different designs for sure, but no need to introduce a flattener into the imaging train.

David"

Don't want you to think that I didn't know the difference between a triplet and a fourplet.

David

Edited by David Pavlich (09/09/13 01:39 PM)


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ManuelJ
professor emeritus


Reged: 12/19/05

Loc: Madrid, Spain
Re: Astro-Physics the Best Brand? new [Re: Jon Isaacs]
      #6071560 - 09/09/13 03:36 PM

Quote:

I like my NP-101 but I have to think that if I had the chance to trade it straight across for a Traveler, I would jump on it.




I would to that in a heartbeat (IS version). If you are doing a trip to Madrid, call me


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Eddgie
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Reged: 02/01/06

Re: Astro-Physics the Best Brand? new [Re: David Pavlich]
      #6071601 - 09/09/13 04:07 PM

David,
The real limitation is chromatic aberration, which as you know, scales with aperture.

Building an imaging scope a 102mm or even 130mm is far less demanding than getting that same performance in a very large telescope.

The large APs are aslo corrected at wavelenths that most scope can't touch.

But this is not a argument I or anyone else can win, so I won't post on the topic again, but when you look at the AP scopes as imaging scopes, they are across the board excellent, and the largest ones are perhaps peerless.

And used prices alone classify them as "Best" because discerning people will always pay more for the best. Even if it is higher than new price.


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BPO
sage


Reged: 02/23/10

Loc: South Island, NZ
Re: Astro-Physics the Best Brand? new [Re: Eddgie]
      #6071652 - 09/09/13 04:44 PM

IIRC, Tak's TOAs are optimised for imaging, rather than visual, and even Roland said for astrophotography he'd choose a TOA over one of his own.

But this kind of thread is certain to bring out the bitterest in fanboys.



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David PavlichAdministrator
Transmographied
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Reged: 05/18/05

Loc: Mandeville, LA USA
Re: Astro-Physics the Best Brand? new [Re: Eddgie]
      #6071662 - 09/09/13 04:50 PM

Quote:

David,

And used prices alone classify them as "Best" because discerning people will always pay more for the best. Even if it is higher than new price.




And from my first post in this thread:

"But if you factor in resale, AP is the clear winner."

Not trying to argue here. I'm mentioning facts (triplet needs flattener, Petzval doesn't. AP has the best resale hands down and when figuring that into the equation, yes, AP is the best). The only way that we would be able to prove which brand has the best correction would be to have one person with the same setup shooting the same object with the same seeing and the same person doing the processing and that person can't own a refractor so that he or she doesn't have a dog in the hunt.

Pretty tough to do, however, due to the enormous cost of 6" top line apochromats. I stop at 6" because it's the largest that Tak makes.

I know AP is arguably the best refractor out there and would be beyond my capability as an imager or my astro-bank account. So...that's why I have a C11 Edge...I can afford it.

David


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PeterR280
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Reged: 05/27/13

Re: Astro-Physics the Best Brand? new [Re: BPO]
      #6071665 - 09/09/13 04:50 PM

If the APs are primarily an imaging telescope, why are the field flatteners sold as an option?

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M13 Observer
scholastic sledgehammer


Reged: 12/09/06

Re: Astro-Physics the Best Brand? new [Re: PeterR280]
      #6071690 - 09/09/13 05:01 PM

Quote:

If the APs are primarily an imaging telescope, why are the field flatteners sold as an option?




The 155EDF, 180EDF and 175EDF were only sold with the 4" field flattener included. As to the rest of the AP scopes, "Primarily" does not mean "solely". A dedicated AP field flattener will set one back around $800 to $2000. If you have a small CCD chip or or only using the scope visually, it is not required so why pay for it if you don't need it?


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David PavlichAdministrator
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Reged: 05/18/05

Loc: Mandeville, LA USA
Re: Astro-Physics the Best Brand? new [Re: PeterR280]
      #6071694 - 09/09/13 05:05 PM

I don't think any of the top line triplets come with a flattener as part of the package. I would assume that the cost would rise and that someone that is buying it for visual only would be a bit miffed paying extra for a flattener to be used for imaging.

David


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BPO
sage


Reged: 02/23/10

Loc: South Island, NZ
Re: Astro-Physics the Best Brand? [Re: David Pavlich]
      #6071703 - 09/09/13 05:09 PM

Quote:

The only way that we would be able to prove which brand has the best correction would be to have one person with the same setup shooting the same object with the same seeing and the same person doing the processing and that person can't own a refractor so that he or she doesn't have a dog in the hunt.



Patriotism is likely to play a significant role, unfortunately. In this particular debate it always does.


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RodgerHouTex
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Reged: 06/02/09

Loc: Houston, Texas, USA
Re: Astro-Physics the Best Brand? [Re: PowellAstro]
      #6071737 - 09/09/13 05:23 PM

I believe I read somewhere that A-P uses machines to grind and polish their lenses and then Roland hand figures them. No hand grinding and polishing required.

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