#11
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"Disappointing" is a highly subjective term. Although I don't necessarily
disagree with the idea that a 3" jump isn't as great as a 10" jump. ;-) But I would never recommend an 18" Dob. You have to come to that on your own, as a slow progression up the aperture fever ladder. There is also by virtue of differences in geographic location, a lot of subecjtive matter to work through, which is why participating in a local group of amateur astronomers is the best way to work through all the fuss of settling on the right scope. For me, that currently seems to be a C9.25 on a G-11 with ScopeBuggy, and all the necessary accessories to combat the elements, along with an electronic finder system. It best suits my style of observing in concert with my local atmospheric conditions, as well as my budget, and my home base conditions. I don't go out of the yard often enough to focus on a scope that best suited that need. Instead I concentrated on what it would take to get me out in the backyard on most clear nights, without being thwarted by conditions within the control of available technology. Astronomy is not a life pursuit for me, where I venture off into the wilderness every chance I get, to hunt down the wonders of the universe under pristine skies. It is something I do in my spare time, from my back yard. I've concluded that between tucking the kids in bed, and going to sleep, it is better to go out for an hour or two and swing the scope around using RA and Dec counters, than it is to sit in the house on my ass, and miss the chance to look at all those wonderful star clusters. I don't care how they get in the eyepiece, the easier that is, the better. Hunting down an object in a huge scope just doesn't relax me as much as looking through the eyepiece. I'd rather struggle with a dim object in the eyepiece for 5 or 10 minutes, than struggle with a red light and a chart that I can't read without my reading glasses. Keep in mind that no matter what the aperture, there are always objects of any given class that are "dim". I think it's better to become intimately familiar with those objects you can see well, in whatever aperture you have on hand at the time. Including a little 80mm ED refractor on a simple altazimuth mount. Especially with objects you know so well as to find them in 10 seconds without so much as a red dot finder. Subjectively yours, -Stephen "Doink" wrote in message ... Unless you have a very well trained eye, the difference will be disappointing----you are chasing small increments of "improvement". From your 8", the next real step upwould be a 18" DOB. Doink "Mark D" wrote in message ... The one thing to remember, is an 8" compound scope (of mostly any type note), is not technically a 8" scope due to secondary obstruction. The 11" will show you more detail, nebulosity, fainter stars, and split closer doubles under virtually any sky conditions, urban, suburban, and dark sky. Naturally, aperture will truly shine, and have the advantage under dark, transparent sky conditions. Also to remember, the larger the aperture, generally, the longer the cooldown period. There are ways around this. Lymax cooling fans, setting scope up prior to an observing run, etc. Dark sky conditions are not needed to do serious Planetary-Solar-Lunar observation-imaging. What is needed is a steady calm atmosphere, and equilibration of the scope. With Solar Imaging-Observing, there probably wouldn't be much gained between the 8"SCT, and the 11" SCT with white light filter. Mark |
#12
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Another Oink from Doink..... oink oink!
Yeah, I owned 8" and 11" SCT's at the same time and the 11" blew the 8" clear out of the water. Even against my well-optimized 10" Zambuto Newt, the one extra inch of the 11" still gave it the edge in terms of light grasp (fainter stars visible at the same x). BTW, I gave the Newt a tune-up today so I can get back to using it for DSO's. It is currently my biggest aperture scope. I need to get a new focuser for it. rat ~( ); |
#13
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Mark---
Did I say the differences would not be discernable? NO. I said the difference would be disappointing. You can demonstrate by mathematics what the differences are---more light gathering, higher resolving power, etc., but will he be stunned at the difference when he takes that first look in the eyepiece? I doubt it. And that is my point.....and size and weight aside, what about dumping more money into a small increment of gain? Of course, if he pays ENOUGH, he WILL see a big difference! The AA ego is huge and I've never seen a bad review!!!!!!!!!!!! Doink "Mark D" wrote in message ... Unless you have a very well trained eye, the difference will be disappointing----you are chasing small increments of "improvement". From your 8", the next real step upwould be a 18" DOB. Doink ====================================== This statement you have made Doink I have to disagree with in part. First off, I believe the differences would easily be seen by a rank beginner, particularly, if each of these scopes previously mentioned sat side by side, and I feel that the differences would not be "disappointing" as you say. Nor, is the next real step up from an 8" SCT, an 18" Newtonian. I feel that in the SCT department, once one starts to go above 8" of aperture, thats when one can start to appreciate the increase in aperture. An 8" SCT has always left me wanting more. I've found personally, that an 8" SCT usually just begins to resolve many globular clusters, while the larger SCT's will resolve them quite nicely. While as you say, small increments will be noted, and this will be somewhat true under light polluted skies with DSO's, the difference in planetary detail using an 8" SCT vs an 10"-11" SCT will be quite apparent on Planetary. Naturally, the downside becomes size, and weight with the larger SCT's. Mark |
#14
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I can resolve many stars with my MK-67 (6") within the heart of M13. And
can also do so with my 8" reflector. Doink "Pierre Vandevennne" wrote in message ... (Mark D) wrote in news:6143-4338D1DE-530@storefull- 3177.bay.webtv.net: aperture. An 8" SCT has always left me wanting more. I've found personally, that an 8" SCT usually just begins to resolve many globular clusters, while the larger SCT's will resolve them quite nicely. Can't agree more. Whereas M13 just hints that it actually contains stars in an 8" (my skies are poor, your mileage may vary), it definitely sparkles in a C11. The difference isn't as marked visually on the planets, afaic, but that mostly is due to the fact that my site doesn't really have good seeing but, as soon as one uses a webcam, the difference is blatant. If you haven't seen a C8 and a C11 side by side, I suggest you take a look. You might be surprised by the bulk of the C11. |
#15
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"Doink" wrote in
: power, etc., but will he be stunned at the difference when he takes that first look in the eyepiece? I doubt it. Give it a try. -- Pierre Vandevenne - DataRescue sa/nv - www.datarescue.com The IDA Pro Disassembler & Debugger - world leader in hostile code analysis PhotoRescue - advanced data recovery for digital photographic media latest review: http://www.pcmag.com/article2/0,1759,1590497,00.asp |
#16
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"Doink" wrote in
: I can resolve many stars with my MK-67 (6") within the heart of M13. And can also do so with my 8" reflector. That's what I said an 8" (my skies are poor, your mileage may vary), it definitely For example, light pollution makes it impossible for me to get fully dark adapted - I can read magazines outside at night almost wherever I go in Belgium. This being said, all other things being equal, the difference with the C11 is really visible. -- Pierre Vandevenne - DataRescue sa/nv - www.datarescue.com The IDA Pro Disassembler & Debugger - world leader in hostile code analysis PhotoRescue - advanced data recovery for digital photographic media latest review: http://www.pcmag.com/article2/0,1759,1590497,00.asp |
#17
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Scary. I find myself growing in agreement with you with each post.
Doink "Stephen Paul" wrote in message ... "Disappointing" is a highly subjective term. Although I don't necessarily disagree with the idea that a 3" jump isn't as great as a 10" jump. ;-) But I would never recommend an 18" Dob. You have to come to that on your own, as a slow progression up the aperture fever ladder. There is also by virtue of differences in geographic location, a lot of subecjtive matter to work through, which is why participating in a local group of amateur astronomers is the best way to work through all the fuss of settling on the right scope. For me, that currently seems to be a C9.25 on a G-11 with ScopeBuggy, and all the necessary accessories to combat the elements, along with an electronic finder system. It best suits my style of observing in concert with my local atmospheric conditions, as well as my budget, and my home base conditions. I don't go out of the yard often enough to focus on a scope that best suited that need. Instead I concentrated on what it would take to get me out in the backyard on most clear nights, without being thwarted by conditions within the control of available technology. Astronomy is not a life pursuit for me, where I venture off into the wilderness every chance I get, to hunt down the wonders of the universe under pristine skies. It is something I do in my spare time, from my back yard. I've concluded that between tucking the kids in bed, and going to sleep, it is better to go out for an hour or two and swing the scope around using RA and Dec counters, than it is to sit in the house on my ass, and miss the chance to look at all those wonderful star clusters. I don't care how they get in the eyepiece, the easier that is, the better. Hunting down an object in a huge scope just doesn't relax me as much as looking through the eyepiece. I'd rather struggle with a dim object in the eyepiece for 5 or 10 minutes, than struggle with a red light and a chart that I can't read without my reading glasses. Keep in mind that no matter what the aperture, there are always objects of any given class that are "dim". I think it's better to become intimately familiar with those objects you can see well, in whatever aperture you have on hand at the time. Including a little 80mm ED refractor on a simple altazimuth mount. Especially with objects you know so well as to find them in 10 seconds without so much as a red dot finder. Subjectively yours, -Stephen "Doink" wrote in message ... Unless you have a very well trained eye, the difference will be disappointing----you are chasing small increments of "improvement". From your 8", the next real step upwould be a 18" DOB. Doink "Mark D" wrote in message ... The one thing to remember, is an 8" compound scope (of mostly any type note), is not technically a 8" scope due to secondary obstruction. The 11" will show you more detail, nebulosity, fainter stars, and split closer doubles under virtually any sky conditions, urban, suburban, and dark sky. Naturally, aperture will truly shine, and have the advantage under dark, transparent sky conditions. Also to remember, the larger the aperture, generally, the longer the cooldown period. There are ways around this. Lymax cooling fans, setting scope up prior to an observing run, etc. Dark sky conditions are not needed to do serious Planetary-Solar-Lunar observation-imaging. What is needed is a steady calm atmosphere, and equilibration of the scope. With Solar Imaging-Observing, there probably wouldn't be much gained between the 8"SCT, and the 11" SCT with white light filter. Mark |
#18
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"decaf" wrote in news:1127796199.636743.25410
@g43g2000cwa.googlegroups.com: Unless you have a very well trained eye, the difference will be disappointing----you are chasing small increments of "improvement". From your 8", the next real step upwould be a 18" DOB. Upgrading from 8" to 11" aperture, assuming same quality and type of instrument means a nearly two fold increase in light gathering and 27% increase in resolving power, respectively. That is _quite_ significant even to the casual observer. Planets will be more colorful and show more detail, the Moon will be painfully brillliant, and DSO's will have substantially greater visibility. Actually, I don't think it makes any difference at all to the brightness of the moon. This is true in a telescope of any size. Surface brightness cannot be increased by a passive optical system as it would be a violation of thermodynamics. Klazmon. And-- you can run the magnification up to 150x higher than with the 8"er if conditions warrant it; I'd say that's more than a "small increment of improvement". A longer cool-down time will be required though. Dan Chaffee |
#19
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Of course, if he pays ENOUGH, he WILL see a big difference! The AA ego is
huge and I've never seen a bad review!!!!!!!!!!!! Doink ------ Some thoughts: I have seen more than a few negative reviews. If you want a review which severely critizies a scope, a "BAD REVIEW", here's one for you: http://www.cloudynights.com/item.php?item_id=1105 I like David Knisely's reviews on Cloudy Nights, he has been around a a long time and knows what's what, he writes a descriptive review that pretty much lets one know what a skilled observer can do with a given scope, what its strengths and weakness are, just a good well done review. --------------- Personally I see very few "large egos" here or on other astro forums. What I see here are people with varying amount of experience sharing that experience with the hope of helping someone else. That is how I view my role here, helping others and getting help for myself. ----- I will say that my experience with people who are looking through scopes where one collects about twice as much light is that they are indeed impressed. Myself, I am very impressed with the difference between my 70mm Pronto and my 100mm "Burion" (=Burgess OTA + Orion 100mmF6 Achro.) The Pronto is a much higher quality scope but these days I rarely use it simply because the added aperture of the Burion shows more, both DSO and planetary. Jon Isaacs |
#20
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On Mon, 26 Sep 2005 21:48:07 +0000 (UTC),
wrote: I have an 8" Celestron SCT w/ Starbright XLT coatings, and am considering upgrading to an 11" Celestron SCT w/ Starbright XLT coatings. While I have looked through another amateur astronomer's 11" SCT and was very impressed, that experience was at a dark sky location, and I'm accustomed to urban skies. So I'm hesitant; how different will the 11" really be? What more can I expect to see that I cannot see with my 8"? Any experienced responses would be appreciated. I have 8" Meade and 11" Celestron SCTs. The 11" runs rings around the 8" as far as resolving DSOs. There is a noticable difference. I use the 8" mostly for photography but it's a very good scope on its own merits. My NS11 is relatively heavy but is quite manageable and compact for an 11 inch scope. I used to have a 10" Dob with a very nice Parks mirror and the Celestron has proven to be even better. I don't think you can go wrong, especially under light polluted skies, with more aperature. |
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