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Refractor VS Reflector

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#51 Iwi

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Posted 14 May 2006 - 04:46 PM

we all know a bigger and cheaper Newt can beat any refractor on detail and digging out the dim fuzzies like Arp Madore 1. It's just a matter of how much larger your Newt has to be to beat the refractor.

Anybody thinking their refractor has the best views possible has never looked through a large reflector. The refractor may have the best views possible for a 4" or 6" or 8" scope, but the best 8" isn't going to beat a well-built and operated 12, 14, 16, or 18, let alone a 22, 25, 28, 30, 32, 36, 40, etc.
If I went into it knowing it's the best for a given aperture, that's different. Then I'm just buying the best for a certain set of conditions, knowing there are better choices.


I agree. Inch per inch, a refractor is better than an obstructed newton. That's just physics.
However, sooner or later, aperture will rule them all. :-)

If people want to spend lots of money on expensive glass and they know what they're spending it on, I wouldn't regard it as a scam, but as a personal(!) and informed choice.

#52 David Pavlich

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Posted 14 May 2006 - 04:54 PM

It seems to me that no matter how nice the view is from an Astrophysics Apo, it will NEVER be as spectacular as the view from a 15" Obsession. Yes, the stars will be really sharp, but what about the object in question, say M101. All those foreground stars look terrific in the refractor, but that M object is really something in that Newt. There is no logical argument. Aperture, especially when we're talking about 6 or more inches, ALWAYS wins.

My 80mm WO is terrific, but look at M13 through it then through my lowly 6" achro and there is no comparison. The ole' achro wins. Now bright objects brings a different perspective in this comparison, but not so between an 8" Apo and a 16" Newt. 16" resolves a lot more than 8".

BUT, as stated so often, it's what you're looking for when you view. That's all that really matters.

David

#53 Bob W6PU

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Posted 14 May 2006 - 07:41 PM

I didn't see any comments about this, so maybe it was overlooked!

I refer to the ultimate shootout of reflectors Vs refractors.

The Pons, 10" f/16 APO Zeiss refractor was compared side by side at the same magnification levels to the
Grissom 11.75" f/6.4 Newt. reflector on Saturn.......The consensous of opinion was that the Grissom designed reflector WON, HANDS DOWN!

Bob

#54 oldsalt

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Posted 14 May 2006 - 07:55 PM

Just my $.02, each type scope be it refractor, reflector, or compound (i.e. SCT/MAK/SNT) excelles under certain conditions. There is no perfect scope, if there was such a scope, noone could afford one. Even the Hubble has its limitations. We all have reasons we own the scopes we do, and wish for the scopes we do. This horse should have been buried a long time ago.

I've owned a newt, and currently have aSCT and 2 refractors, I still want a newt but this time it will be a mid sized DOB in the 12-16" range because of what it can do. will i sell my other scopes - no because they all compliment each other.

#55 Starman1

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Posted 14 May 2006 - 11:32 PM

I spend the bulk of my observing time on the planets and the moon.
Bucky

Do you observe only in a light-polluted site? I just have a hard time understanding why a telescope owner, under a sky filled with thousands of objects to view, observes, primarily, only a small handful of objects. That isn't to say the planets and Moon aren't interesting--merely that they are only a few of thousands of interesting objects.
It is obvious there are many observers who share your passion for the planets. And I think it often relates to the fact that so many of us live under too-bright skies.
But, If the planets became all there were, though I'd probably still observe them, I'd regard my life as substantially impoverished. I simply cannot comprehend the orientation that makes planets so high a percentage of what's observed.
Yes, I know....I'm a little touched. But I do find it a mystery.
Well, it takes all kinds to make a world.

#56 galaxyman

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Posted 14 May 2006 - 11:48 PM

Since you SRFs won't stop beating the dead horse, there is some snob appeal to claiming your refractor is only a _", and rivals Newts that are a couple inches larger. In a way, it's a scam, because we all know a bigger and cheaper Newt can beat any refractor on detail and digging out the dim fuzzies like Arp Madore 1. It's just a matter of how much larger your Newt has to be to beat the refractor.

I think of the woman who bought a Cadillac Escalade to drive up the mountain to her hillside property. She got scammed because it doesn't have a low range in its transfer case. Anybody thinking their refractor has the best views possible has never looked through a large reflector. The refractor may have the best views possible for a 4" or 6" or 8" scope, but the best 8" isn't going to beat a well-built and operated 12, 14, 16, or 18, let alone a 22, 25, 28, 30, 32, 36, 40, etc. For the price of a top 8" refractor, I can buy five 30" reflectors. Believe me, I would feel scammed if I spent $100,000 on a refractor marketed as "the best", only to learn that I don't have a chance to see 1/5 the objects that an 18" reflector can show me, and that the reflector shows me more detail on every target below mag 15, or mag 10, or mag 5, ad nauseum. If I went into it knowing it's the best for a given aperture, that's different. Then I'm just buying the best for a certain set of conditions, knowing there are better choices.


This guy knows what he is talking about. The money you end up spending IS a scam. For some 8" APO that requires additional HUGE and EXPENSIVE mounting, I can spend a fraction of the price and still have a fine 20" reflector of excellent quality. When it comes to resolving the finest detail - I'm not sorry btw - aperture wins. The refractor forum is where people need to argue the superiority of refractors and not take it personally when someone says they are just so darn expensive. Best for a given aperture.... Hmmm.... Let's say my 12.5" f/5 or 20" f/5 Obsession eats a 8" whatever design for breakfast. Am I at the reflector forum??


Yes, aperture does win, but the original question is what is best reflector or refractor. Inch for inch in almost all instances it's the refractor. As owner of both, and as I previously stated my 22" dob is still most important to me, because of all the galaxies I view and love. So I'm not one sided in favor of the refractor.

The reason I bought the 8" f/9 refractor is because?

1. I like big aperture in both refractors as well as reflectors.
2. Though a larger reflector may see more, the refractors image is different. More contrast, better clarity. For instance M-13 in my 22" dob is fantastic. Though the view in a large refractor may not have as big bold view of the much larger reflector, it is still quite stunning with stars as the tiniest pin points in the blackest background. Yes, the larger dob shows more, both are beautiful but also different.
3. Challenge. I will push this new scope to the max.

If you think that all scopes(types)images through the eyepiece are the same, it's not. The dobs biggest advantage is sheer aperture, though I still demand high quality optics. The refractors biggest advantage is clarity and the highest contrast.

For instance, say you take a dob and a refractor of equal high quality optics and light gathering. Put them on the same DSO object. Do you think the view would be the same? No, the refractor will be more pleasing by it's crystal clear higher contrast view. It's not just the quality optics, but the design of the scope.

So your logic suggest if you don't have a BIG dob your just wasting your money. I guess that also implies to owners of not only refractors, but also expensive SCT's and all other types of scopes. So all of them got scammed also? Now who is the snob?

It's not just about price, and that people like me are wasting their money. It's about some of the reasons as stated above.

Keep an eye for my review of the 8" f/9 refractor from one of our (Chesmont Astronomical Society) dark sites, it will be thorough and honest. Hopefully I'll know what I'm talking about :question:

Now only if the sky would clear in the next week or two.

Karl

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#57 claytonjandl11

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Posted 15 May 2006 - 02:10 PM

[/quote]

Yes, aperture does win, but the original question is what is best reflector or refractor. [/quote]

Sorry but the original question (that I aksed concerning, what Al Nagler told me which is THE beginning thread) was not which is better, refractor or reflector. But at what point in appeture does a high quality Newt. reflector equal a refractor. It was a very simple question, and only a handfull of replies have answered it or attemped to answer it.

What ever scope I have be it a refractor or Newt. Dob. I enjoy them without worrying which is better or what Mag. I'm using, that is always determined by the seeing conditions and how dark are my skies.

I know my subject title sounds as if this thread is about which better but it is not.

Nick T.

#58 reflector74

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Posted 15 May 2006 - 05:42 PM

[quote name="claytonjandl11"] [/quote]

Yes, aperture does win, but the original question is what is best reflector or refractor. [/quote]

Sorry but the original question (that I aksed concerning, what Al Nagler told me which is THE beginning thread) was not which is better, refractor or reflector. But at what point in appeture does a high quality Newt. reflector equal a refractor. It was a very simple question, and only a handfull of replies have answered it or attemped to answer it.

What ever scope I have be it a refractor or Newt. Dob. I enjoy them without worrying which is better or what Mag. I'm using, that is always determined by the seeing conditions and how dark are my skies.

I know my subject title sounds as if this thread is about which better but it is not.

Nick T. [/quote]

Coulda fooled me and the other reflector afficionados.

#59 cvedeler

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Posted 15 May 2006 - 07:34 PM

When I looked through a 6” Astrophysics refractor, I was blown away by the contrast and the sharpness of the view. Stars looked like specks of glitter on black velvet. It was a fairly low power view as I recall, but it knocked my socks off in terms of aesthetically pleasing to my eye. I don’t recall seeing such pristine view through any other telescope… ever. I’ve looked through my share of top of the line reflectors all the way up to 42 inches.

I can see the appeal of a top quality refractor. That said however a good reflector will show FAR more of what’s out there dollar for dollar. We are talking night and day difference here. I’ve never seen a spiral arms on M51 through a refractor, and even though the APO refractor views are pleasing to the eye, they don’t compare to the details, brightness and resolution available to even a modestly larger reflector. They both have their place in the world of amateur astronomy IMO. I wouldn’t mind a 6” Astrophysics, and would probably pay a fair amount for one given the chance. But if I could only have one telescope I would go with a 12” – 15” reflector because as an astronomy workhorse it is still small enough to lug around and large enough to provide some serious viewing.

I'm quite happy with my 12" Lightbridge for the moment and although it doesn't quite have the "snap" of a 6" Astrophysics, I can see so much more with it at 1/8th the price. :jump:

#60 reflector74

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Posted 16 May 2006 - 01:45 PM

When I looked through a 6” Astrophysics refractor, I was blown away by the contrast and the sharpness of the view. Stars looked like specks of glitter on black velvet. It was a fairly low power view as I recall, but it knocked my socks off in terms of aesthetically pleasing to my eye. I don’t recall seeing such pristine view through any other telescope… ever. I’ve looked through my share of top of the line reflectors all the way up to 42 inches.

I can see the appeal of a top quality refractor. That said however a good reflector will show FAR more of what’s out there dollar for dollar. We are talking night and day difference here. I’ve never seen a spiral arms on M51 through a refractor, and even though the APO refractor views are pleasing to the eye, they don’t compare to the details, brightness and resolution available to even a modestly larger reflector. They both have their place in the world of amateur astronomy IMO. I wouldn’t mind a 6” Astrophysics, and would probably pay a fair amount for one given the chance. But if I could only have one telescope I would go with a 12” – 15” reflector because as an astronomy workhorse it is still small enough to lug around and large enough to provide some serious viewing.

I'm quite happy with my 12" Lightbridge for the moment and although it doesn't quite have the "snap" of a 6" Astrophysics, I can see so much more with it at 1/8th the price. :jump:



Amen to your logic. 6" of scope is still 6" of scope, pleasing views or not, and it's sure a heck of a lot of money to fork over for visual observing. Also, people must consider the appropriate exit pupils that are comfortable to observe with at mid-high powers when the atmosphere allows. I don't care what the design of the telescope is because aperture means everything when it comes down to what can be seen at the eyepiece. I know that a smaller central obstruction makes for higher contrast but that's just common sense. 20% or lower is desireable.

Same goes with selecting eyepieces that don't put 27 additional glass elements into the focal plane to rob light and further diminish contrast.

Again, when you buy a very expensive 6" refractor, you also require a very expensive, top of the line equatorial mounting as well. Seems like a huge price to pay for an exquisite view in a particularly small aperture class. Good grief...

#61 Alan French

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Posted 16 May 2006 - 02:03 PM

Sorry but the original question (that I aksed concerning, what Al Nagler told me which is THE beginning thread) was not which is better, refractor or reflector. But at what point in appeture does a high quality Newt. reflector equal a refractor. It was a very simple question, and only a handfull of replies have answered it or attemped to answer it.
[SNIP]
Nick T.


Nick,

Did you ever look up the two part article "Rules of Thumb for Planetary Telescopes," by William Zmek in the July (page 91) and September (page 83), 1993, issues of Sky & Telescope.

It will very nicely answer your question.

Clear skies, Alan

#62 Alan French

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Posted 16 May 2006 - 02:38 PM

Amen to your logic. 6" of scope is still 6" of scope, pleasing views or not, and it's sure a heck of a lot of money to fork over for visual observing. Also, people must consider the appropriate exit pupils that are comfortable to observe with at mid-high powers when the atmosphere allows. I don't care what the design of the telescope is because aperture means everything when it comes down to what can be seen at the eyepiece. I know that a smaller central obstruction makes for higher contrast but that's just common sense. 20% or lower is desireable.

Same goes with selecting eyepieces that don't put 27 additional glass elements into the focal plane to rob light and further diminish contrast.

Again, when you buy a very expensive 6" refractor, you also require a very expensive, top of the line equatorial mounting as well. Seems like a huge price to pay for an exquisite view in a particularly small aperture class. Good grief...


People vary in how they spend their money, and there are certainly many hobbies where folks can spend far, far more than anyone spends on a fine refractor. (Just look at all those boats tied up in any marina.) From a cost standpoint, there is no doubt that the Newtonian reflector on a Dobsonian mount provides the best value for the money. As you say, a central obstruction of 20 percent or less is not worth worrying about. I don't spend much time fretting about what other people spend their money on either.

I think APOs really shine, and make financial sense, in the smaller apertures. You get a nice, portable telescope that provides low power, wide field views unavailable in other instruments, yet it can provide the best possible views at high powers for that aperture. They also double as great nature/birding scopes. Many of them are legal airline carry on size. I've had small, rich field Newts, and they just don't do as well on the sky, and are pretty useless during the day.

Aperture alone does not always determine what you see. Here in upstate New York, where the temperature often drops much of the night, large mirrors always lag ambient air temperature, and simply do not provide good planetary views. The lunar and planetary views through a moderate sized APO, or Newtonian, are far better and reveal more detail.

An expensive APO requires an expensive mount no more than a good Newtonian does. I've seen folks with some very slick and inexpensive mounts for their expensive APO. Of course, if you do put it on a nice equatorial, tracking is a huge advantage when seeking out subtle planetary detail. Any serious planetary observer using a Newtonian really should invest in a good equatorial mount, tracking platform, or computerized altazimuth tracking. (This helps when trying to get the most out of DSOs too.)

There is one area where refractors are unmatched - solar observing. I have yet to see a vanilla Newt set up for H-alpha viewing, or that provides white light views similar to what I've seen through some good APOs.

Aperture and design matter little. It is what you do with the telescope that is important. Any telescope can provide a lifetime of enjoyment, and if you are enjoying the night sky, who cares how much or how little you spent, or what you spent your money on?

Clear skies, Alan

#63 mttafire

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Posted 16 May 2006 - 02:44 PM

Id like to someday have one of each..Maybe a grab and go refractor to go with my dob..

#64 Alan French

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Posted 16 May 2006 - 03:57 PM

One reason that APOs tend to be so pricey is that they were - at least those from AP - intended for wide field imaging. They need to be highly corrected over a wide field for a wide range of colors, and the mechanics have to be able to support heavy cameras well. They may be a bit of overkill for visual observers.

Perhaps we will see someone market APOs designed more for visual observers.

Clear skies, Alan

#65 galaxyman

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Posted 16 May 2006 - 10:37 PM

When I looked through a 6” Astrophysics refractor, I was blown away by the contrast and the sharpness of the view. Stars looked like specks of glitter on black velvet. It was a fairly low power view as I recall, but it knocked my socks off in terms of aesthetically pleasing to my eye. I don’t recall seeing such pristine view through any other telescope… ever. I’ve looked through my share of top of the line reflectors all the way up to 42 inches.

I can see the appeal of a top quality refractor. That said however a good reflector will show FAR more of what’s out there dollar for dollar. We are talking night and day difference here. I’ve never seen a spiral arms on M51 through a refractor, and even though the APO refractor views are pleasing to the eye, they don’t compare to the details, brightness and resolution available to even a modestly larger reflector. They both have their place in the world of amateur astronomy IMO. I wouldn’t mind a 6” Astrophysics, and would probably pay a fair amount for one given the chance. But if I could only have one telescope I would go with a 12” – 15” reflector because as an astronomy workhorse it is still small enough to lug around and large enough to provide some serious viewing.

I'm quite happy with my 12" Lightbridge for the moment and although it doesn't quite have the "snap" of a 6" Astrophysics, I can see so much more with it at 1/8th the price. :jump:


Chris - A good 6" refractor at a good dark site should show you the arms in M-51. My 6" F/8 Meade (very good optics) showed them from a site with a limiting magnitude of 6.3, and my 4.7" showed hints of the arms at a darker site.

Karl

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#66 reflector74

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Posted 16 May 2006 - 10:44 PM

One reason that APOs tend to be so pricey is that they were - at least those from AP - intended for wide field imaging. They need to be highly corrected over a wide field for a wide range of colors, and the mechanics have to be able to support heavy cameras well. They may be a bit of overkill for visual observers.

Perhaps we will see someone market APOs designed more for visual observers.

Clear skies, Alan


We have that option. They are the ED's. I have owned a 100ED btw, and since I don't do much astrophotography, there was no need for me to spend a million dollars on a tiny 4" scope (truly awesome last year on Mars...). Sold it for personal reasons. I have four scopes that kick its butt on everything in the sky in modest apertures at moderately fast focal lengths.

Anyway, to sum it all up, astronomy DOES BELONG TO EVERYONE. In other words, it can be discouraging to owners of any aperture or scope design to pit this scope against that scope.

My hats off to the person who can only afford a couple decent eyepieces and a quality 6" reflector let's say. You'll see me hangin' out with that person at any star party all night long. Aperture shows more, yes, but others on a budget should be highly encouraged for what they can afford to use. Let us perhaps encourage that instead of "what scope design is better".

#67 galaxyman

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Posted 16 May 2006 - 10:54 PM

Karl,

To me, there shouldn't be any contest between the two designs IMHO. I generally prefer Newtonian designs, but I know where to go to spend tons of money if I want the really wonderful exquisite clarity for a particular unit of aperture. I suppose ease of setup with my dobs come into the picture for me. It's a blessing that I now do astronomy day and night. My Coronado SM60 double stacked scope has a CO for its intended purpose! Go figure! That 8" refractor of yours is likely beyond amazing on the planets and a pleasure to observe with... You'll get more good nights of seeing with it than the 22" dob.


Believe it or not the 8" f/9 refractor will still be used as a DSO scope. Hey, I do get to come down the ladder and sit to view.

Hopefully this coming weekend or next week will be first light.

First official object is still up in the air. Want something good but not spectacular (want the build up as the night goes on). It will of course be a galaxy.

Now I wonder how deep this big refractor will go? I do have a few challenges in mind. The site (if the sky is very transparent) has a limiting magnitude of better than 6.5


Karl

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#68 Mark Harry

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Posted 17 May 2006 - 03:56 PM

"Chris - A good 6" refractor at a good dark site should show you the arms in M-51. My 6" F/8 Meade (very good optics) showed them from a site with a limiting magnitude of 6.3, and "

My reworked Orion tube (6"F/8) showed the spiral in M51 easily, direct vision. I always felt that M51 could use more aperture, just one of those objects. Not sure of my sky's dark limit though. Mark

#69 reflector74

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Posted 18 May 2006 - 06:29 PM

"From a cost standpoint, there is no doubt that the Newtonian reflector on a Dobsonian mount provides the best value for the money. As you say, a central obstruction of 20 percent or less is not worth worrying about........."


** That's a very important point to consider in this topic I think.



I think APOs really shine, and make financial sense, in the smaller apertures. An expensive APO requires an expensive mount no more than a good Newtonian does. I've seen folks with some very slick and inexpensive mounts for their expensive APO.

* Not usually. Not as a general fule of thumb.



Of course, if you do put it on a nice equatorial, tracking is a huge advantage when seeking out subtle planetary detail. Any serious planetary observer using a Newtonian really should invest in a good equatorial mount, tracking platform, or computerized altazimuth tracking. (This helps when trying to get the most out of DSOs too.)


* Planetary observers might consider moderate focal lengths in mid-sized (say 8" to 10") apertures. A person doesn't really need to have it tracking if your intent is to stare visually (omitting the imaging needs of course) at one object for a long duration.


Aperture and design matter little. It is what you do with the telescope that is important.


* Aperture matters a lot and I really don't understand that logic that "aperture matters little". It sure does make a difference when you intend to see as much as you can visually. Whatever design is chosen - - optical quality is of paramount importance. Of course, if one's intention is faint DSO's and the whole shabang, design begins to take on huge importance as aperture is the name of the game to a visual observer, not ignoring optical quality.


Any telescope can provide a lifetime of enjoyment, and if you are enjoying the night sky, who cares how much or how little you spent, or what you spent your money on?

Clear skies, Alan


* Yes, I have to agree a Newtonian that's equatorial requires a good mount, of course. But my point was on dob mounted Newtonian reflcetors due to the subject at hand. I'm not going to put a gorgeous AP refractor on some silly alt-az mount. It would be on an beautiful AP equatorial mount. Now..when you bring up money and how people choose to spend it, you are right. Folks have the right to spend whatever they want. My argument in "this VS that" is that more financial sense matters to me and most other people. A fine 6" refractor is great. But not so practical to a dedicated visual observer who moves around with their scope lots and is on some kind of budget and want the most bang for the buck. In an observatory setting where the dedication is CCD imaging, the AP or other high end refractor makes perfect sense, though again, affordability must not be an issue. The scope that gets used the most by any one individual is the best scope.

#70 BillFerris

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Posted 18 May 2006 - 09:59 PM

[Reflector74 wrote]

[Alan French wrote]I think APOs really shine, and make financial sense, in the smaller apertures. An expensive APO requires an expensive mount no more than a good Newtonian does. I've seen folks with some very slick and inexpensive mounts for their expensive APO.

* Not usually. Not as a general fule of thumb.

Of course, if you do put it on a nice equatorial, tracking is a huge advantage when seeking out subtle planetary detail. Any serious planetary observer using a Newtonian really should invest in a good equatorial mount, tracking platform, or computerized altazimuth tracking. (This helps when trying to get the most out of DSOs too.)

* Planetary observers might consider moderate focal lengths in mid-sized (say 8" to 10") apertures. A person doesn't really need to have it tracking if your intent is to stare visually (omitting the imaging needs of course) at one object for a long duration.


I have to agree with Alan. Tracking should be at the top of any planetary enthusiast's priority list. You're typically observing at high to very high magnifications. As a result, the fields of view are small and tracking allows you to devote long periods of time to focusing all your attention on the planet while waiting for those moments of steady air.


Aperture and design matter little. It is what you do with the telescope that is important.

* Aperture matters a lot and I really don't understand that logic that "aperture matters little".


I suspect Alan's point is that it's possible to get good use from just about any telescope. Whether you're drinking in a naked eye view of the summer Milky Way, casually sweeping the sky with a richfield APO or drilling for Hickson clusters with a large aperture Dob, there is always good observing to be had. In other words, you don't need large aperture or Swiss watch craftsmanship--and cost--to have fun in this hobby. Similar to photography where great photos are taken by great photographers, great observing is a product of the observer; not the telescope.

Regards,

Bill in Flagstaff

#71 Alan French

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Posted 18 May 2006 - 10:17 PM

Aperture and design matter little. It is what you do with the telescope that is important.

* Aperture matters a lot and I really don't understand that logic that "aperture matters little". It sure does make a difference when you intend to see as much as you can visually. Whatever design is chosen - - optical quality is of paramount importance. Of course, if one's intention is faint DSO's and the whole shabang, design begins to take on huge importance as aperture is the name of the game to a visual observer, not ignoring optical quality.
[SNIP]


If you don't understand "aperture matters little" you have either not been in the hobby long or have not been paying attention. Does everyone you know who enjoys DSOs have a huge Dob? I know a lot of folks who are having a heck of a good time exploring the night sky with very modest telescopes - telescopes you would probably consider severely aperture challenged. We have people in our club who started with modest apertures, and I thought "someday they'll move up." Some of them never did, and they are still having a great time and seeing new things. I go to a lot of conventions, and there are certainly some large Dobs most everywhere, but they are vastly outnumbered by more modest instruments, and I've never gotten the impression many of these folks felt hindered by their lack of a monster Dob.

People like to push the limites of their instruments, and I like to joke that folks use a 4" telescope and look at things they can barely see, and then they move up to an 18" telescope, and look at things they can barely see, and so on.

We have a number of telescopes here, yet my wife always tells people if she could only have one telescope, it would be her 4" Traveler. And she is one serious deep sky observer.

Clear skies, Alan

#72 Mike B

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Posted 18 May 2006 - 10:28 PM

I'm reminded of Jay Reynolds Freeman & "Refractor Red". Yeah, he's got Harvey too. But doesn't stop him from cavorting around in the dark with miniscule apertures having loads of fun! I know it ain't right... but what's a guy to do? :lol: :roflmao: Join 'im, i guess... sure ain't gonna beat him... unless ya got a truss-pole handy. :lol:

#73 Daniel Mounsey

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Posted 19 May 2006 - 01:45 AM

I didn't see any comments about this, so maybe it was overlooked!

I refer to the ultimate shootout of reflectors Vs refractors.

The Pons, 10" f/16 APO Zeiss refractor was compared side by side at the same magnification levels to the
Grissom 11.75" f/6.4 Newt. reflector on Saturn.......The consensous of opinion was that the Grissom designed reflector WON, HANDS DOWN!

Bob


This is actually true. Anybody who thinks a 9" apo will out perform a Newt of 11" has most likely never used a properly optimized Newtonian to find out otherwise. I don't know if Nagler's actually ever compared big apochromats to optimized Newts.

#74 reflector74

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Posted 19 May 2006 - 02:28 PM

[quote name="Alan French"][quote]
Aperture and design matter little. It is what you do with the telescope that is important.

* Aperture matters a lot and I really don't understand that logic that "aperture matters little". It sure does make a difference when you intend to see as much as you can visually. Whatever design is chosen - - optical quality is of paramount importance. Of course, if one's intention is faint DSO's and the whole shabang, design begins to take on huge importance as aperture is the name of the game to a visual observer, not ignoring optical quality.
[SNIP][/quote]

If you don't understand "aperture matters little" you have either not been in the hobby long or have not been paying attention. Does everyone you know who enjoys DSOs have a huge Dob? I know a lot of folks who are having a heck of a good time exploring the night sky with very modest telescopes - telescopes you would probably consider severely aperture challenged. We have people in our club who started with modest apertures, and I thought "someday they'll move up." Some of them never did, and they are still having a great time and seeing new things. I go to a lot of conventions, and there are certainly some large Dobs most everywhere, but they are vastly outnumbered by more modest instruments, and I've never gotten the impression many of these folks felt hindered by their lack of a monster Dob.



* Alan, please keep it above the belt, sir. I'm not talking about monster dobs. I will say it again. Aperture has everything to do with resolution and what you can see. That's just physics. I believe in modest instruments all the way, and I don't believe in the monster ego dobs. An inexpensive 8" dob of modest aperture to today's standards will gather 4x the light of a teeny 4" apo refractor. For visual observing alone, the 8" makes a heck of a lot more sense financially as well as what you can see with it. It's just a wise purchase if you pit the two scopes together for example. Plus with the 8" dob, one can make good use of narrowband filters, and see many thousands more objects than the 4" refractor. I just consider the title of the thread and its really a no-brainer to me. Notice I am not insulting you in any way, sir. God bless.

#75 Mark Harry

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Posted 19 May 2006 - 03:15 PM

I for one am in the small aperture/excellent optics catagory. I've chosen to remain there, and I always have a 6-8" scope that generally gets used much more than the bigger stuff At the risk of offending the "big glass" crowd, I have to say that there are few instances where the trouble messing with the big scopes is really worth the effort, and truth be known, I'm willing to wager there is a tendency to get optical trains that as a rule are inferior to smaller aps. When the weight of just the glass alone warps the mirror into a potato chip, I think I'd rather put my efforts into something else that's more consistent and with higher quality. With good smooth accurate optics, filters don't help that much.(also, if of that high quality, there won't be much to choose from whether its a reflector or refractor.) My 2 cents.
Heck, whether I'm using a pair of cheap binoculars, a 4.5", 6, 8 or larger, I always find something interesting to do with the scope I have. How could it be otherwise?!
Mark


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