Daniel Mounsey
Vendor - Celestron
Reged: 06/12/02
Posts: 4899
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You're right David,
I understand. I still believe the 9.25" is the better choice over the 11" but like the other guys said, check out as many reports as you can and get a rounded opinion. I plan to have the report ready by next week, but whether or not cloudynights puts it out soon will be their choice.
Best
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Anonymous
Unregistered
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Quote:
By the way, what's the big deal with the refractor vs. reflector debate? It's no big deal.
The debate itself is good, I don't think David is shopping around for an APO though, so it seems out of place in this thread.
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Daniel Mounsey
Vendor - Celestron
Reged: 06/12/02
Posts: 4899
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What's there to debate about anyway. Don't you think people ought to have a grasp on the situation by now?
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Anonymous
Unregistered
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Exactly 
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 5618
Loc: San Francisco Bay Area, Calif...
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Quote:
Quote:
Has anyone seen a really good planetary image from a C11? I can't remember when I have. But, then I've not seen a really nice looking planetary image from a 12" Meade either.
Too bad.
I have, and several examples of each. Damian Peach for one comes to mind as Jim pointed out.
http://www.damianpeach.com/images/best/feb19_natural.jpg
http://www.damianpeach.com/images/saturn/2003/s2004_03_01lrgb.jpg
http://www.damianpeach.com/images/best/best_all.jpg
The views I've had through my C11 in moments of steady seeing have been razor sharp.
The best imaging conditions I've ever had since buying it though were 6-7/10 for brief moments at best, we'll see what happens with a better night.
I know you're big on APO's, but David is not interested in buying an APO.
Hi Robert,
I'm glad you are happy with the views through your C11.
I've said that I've seen fine planetary detail in a C8 with my AP 155EDFS along side for comparison. I have quite a bit of experience in the field with both types of telescopes. Please note the two scopes I'm talking about are not too far apart in aperture.
The problem with supporting your argument by way of links to images made with SCTs is, that imaging and visual work is very different. Our eyes don't process information the way computers can. Imaging and visual work is apples and oranges.
No, I'm not trying to sell David on an APO. If he wants to do mostly imaging of planets there are other groups that can give him lots of good advice. I can't help much with imageing. I'm a visual guy.
Rich
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 5618
Loc: San Francisco Bay Area, Calif...
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Quote:
What's there to debate about anyway. Don't you think people ought to have a grasp on the situation by now?
I think David does grasp the situation.
Rich
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Anonymous
Unregistered
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Quote:
Has anyone seen a really good planetary image from a C11? I can't remember when I have. But, then I've not seen a really nice looking planetary image from a 12" Meade either.
Too bad.
Quote:
Hi Robert,
I'm glad you are happy with the views through your C11.
I've said that I've seen fine planetary detail in a C8 with my AP 155EDFS along side for comparison. I have quite a bit of experience in the field with both types of telescopes. Please note the two scopes I'm talking about are not too far apart in aperture.
The problem with supporting your argument by way of links to images made with SCTs is, that imaging and visual work is very different. Our eyes don't process information the way computers can. Imaging and visual work is apples and oranges.
No, I'm not trying to sell David on an APO. If he wants to do mostly imaging of planets there are other groups that can give him lots of good advice. I can't help much with imageing. I'm a visual guy.
Rich
The links were in response to your comments above, do you remember making those comments about C11 images?
Where is my "argument" about observing/imaging or anything else?
There is none.
My point here was to try and get back on topic for David's sake, as David is a good friend of mine and I know first hand he's not after an APO.
Give it a rest already.
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jrcrilly
Refractor wienie no more
Reged: 04/30/03
Posts: 30716
Loc: NE Ohio
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Quote:
No, I'm not trying to sell David on an APO.
Cool. Any input on C11 v. C9.25? I've stayed out of this one because although I've owned several C11's and C8's I haven't owned a C9.25 .
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John C
Battle Cry of Reno
http://www.wadsworthobservatory.com
My Cloudy Nights gallery
AT12RC
AT65EDQ
QSI683WSG-8
Roper Scientific Quantix 6303E "project" camera
mystery EQ mount on the way
Edited by jrcrilly (02/12/05 08:00 AM)
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celestial_search
Carpal Tunnel
Reged: 11/18/04
Posts: 2569
Loc: Iowa, USA
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I think that David's question posed to Greg (what do you think about Mr. Daniel Mounsey's concept of the C9.25 when he wrote that this SCT would beat out any $8000 5" APO system there is for planets (and there's still an even more dramatic report to come: He must be working on his next C9.25 Vs. $10000 6" APO report, where he would confirm or rule out this great SCT outperforming the mentioned APO...(I wish I could read that report before my purchasing!)WHAT ARE YOUR THOUGHTS ABOUT IT?) was based on his curiosity after reading some reviews (which included some comparisons between SCTs and APOs).
He is probably curious, anxious, and perhaps overwhelmed all at the same time because of the investment involved in the C-9.25.
This thread actually has valuable information (a strong point of Cloudy Nights) and I don't view it as "competition" between scope types, although I can see how some people might view it that way. If you went to any other site you would not find the quality of information and overall congenial atmosphere that you do here. I've learned a lot from reading the posts on this thread and enjoyed the feedback and thanks to everyone for sharing. I would also be curious, as John is, about how the 9.25 compares to the C-11.
More importanty, I hope David learned a lot and feels comfortable with his decision.
We are all united by our hobby regardless of the type of scope we use. 
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Frank
C-11 XLT
8" f/6 Newt on GEM
Tak FS-102II
SV 80L Triplet APO
EQ-6 Mount on pier in backyard observatory (EQMOD)
CG-5 AS (GOTO)
SBIG ST-5C CCD and Canon Rebel XSI
SSAG
Oberwerk 15X70s and Pentax 10X21s
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Don W
demi-god
Reged: 05/19/03
Posts: 19226
Loc: Wisconsin, USA
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In the summer of 2003 the best views I had of Mars were through my Nexstar 11GPS. I've used that scope next to my friend's excellent 9.25" and I don't see the latter doing better than the 11". Will a 6" or 8" apo do better? In my experience, yes to the 8". I've seen Saturn and Jupiter through an 8" AP and the images are permanently emblazoned into my memory. The 6" isn't far behind but I think the SCTs will hold their own in that comparison.
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DON'T PANIC!-Hitchhiker's Guide to the Galaxy
Don Wyman
Obsession 18" f/4.5 #1166
W/Argo Navis DSC and Torus Primary
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Daniel Mounsey
Vendor - Celestron
Reged: 06/12/02
Posts: 4899
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Frank,
I totally agree wit you. Don, it's interesting that you mention the 9.25" vs. 8" Apo. We conducted a very careful side by side with the two. This was an 8" F-9 TMB. In this particular comparison we were at Mt. Wilson under sub arc second skies during the Mars fest. When we went back and forth between the two, the 9.25" was not that far behind, but the 8" apo still had the edge in detail, contrast and sharpness, but we were all still amazed at how close the 9.25" was. Something some people may want to know is that when you are working with these large apos, they tend to pull in crisp detail that goes unseen in scopes of similar apertures of different designs. When you are patient, lots of detail can be descerned in these big apos, like grooves in the B ring of Saturn etc. I'm not neccessarily saying that the C11 can't beat out a 9.25", it's just that I find it less likely because of cooling issues and problems with collimation shift during focus in the C11. The 9.25" is almost immune to the collimation issues and thus, it tends to be more consistant as a whole. Apos are consistant because nothing goes wrong with them. They bypass all the things observers don't understand and do it for you, but a Newt in the hands of a skilled observer is amazing. I don't want to bag in the SCT forums, but it's really hit and miss with SCT's. I'm a purist and the 9.25" just tends to be my choice. This same 9.25" was next to a really good C14 once on Jupiter and the C14 won, but do you really think every C14's gonna do that?
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Don W
demi-god
Reged: 05/19/03
Posts: 19226
Loc: Wisconsin, USA
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It's always fun to postulate on what type of scope design gives the best images of this object or that, and in my book, the refractor will always come out ahead even if a couple inches smaller. The problem is cost. Not many of us can afford an 8" or even a 6" APO refractor and the mount that it needs.
And while a 6" or 8" Apo will do wonderful things on the moon, planets and double stars, it quickly falls behind when you start looking at faint fuzzies. When it comes to details in NGC galaxies, give me a big dob please. A big SCT in the 10" and up range will do a pretty fair job too but here again, price becomes an obstacle.
So it really all boils down to what you want to look at and what you can afford. The SCT is not the king when it comes to fine details in the planets or picking out faint arms of a 12th mag NGC galaxy, but it does both reasonably well. That's its niche, a scope that is very good at most things but not excellent in any.
That's my opinion anyway, for what it's worth.
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DON'T PANIC!-Hitchhiker's Guide to the Galaxy
Don Wyman
Obsession 18" f/4.5 #1166
W/Argo Navis DSC and Torus Primary
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 5618
Loc: San Francisco Bay Area, Calif...
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Hi Don,
A few of our club members have Starmaster 14.5" f/4.3 driven Dobs. At least two of them have Zambuto mirrors. They give beautiful planetary images and have enough aperture for fine looks at DSOs.
Again, I've seen three C8s show planetary detail very close to my 6" APO when they were side by side. They had been out several hours to settle down and the seeing was very good. That's a lot of planetary bang for the buck.
One thing I've noticed, SCTs as the come new from the store, are not often spot on in collimation. A little time spent in getting the collimation just right pays off in much better planetary images.
I find Jupiter and Mars more difficult targets than Saturn. Jupiter has lots of low contrast features that require very good seeing and nice optics. Jupiter is my favorite test target.
Rich
Edited by Rich N (02/12/05 02:17 PM)
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David Rivas
Carpal Tunnel
Reged: 05/29/04
Posts: 2431
Loc: Lima, Peru
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Thanks to all those who helped whether with their points of view or their own experiences!
Thanks as well to all the posters who know very well how hard and risky it might be to order from overseas and figured out how I feel.
I still consider this purchase hard and risky as Peru's taxes are extremely high and it's not an "everyday" purchase for people here. Besides that, there's always some fear on getting a lemmon...even from USA as I sometimes read...
However, I feel this thread helps me a lot by reinforcing my decision for the C9.25 itself (that's what I was after by posting this thread!) that's why I needed to thank you all, to each one of you!
I've learned a lot! and far from viewing this thread as a competition among scope types, it has been a very nice example of how human beings are able to help from the bottom of their hearts when it comes to sharing the passion of this great and loved hobby. (no matter distances-in all sense-, viewpoints, or type of telescope...Astronomy was, is and will always be one of our first vehicles to feel happy ourselves! whether helping or just enjoying our hobby)
Thank you very much my friends!
When the time comes, I'll post my new toy's first light!
Regards,
David
Edited by David Rivas (02/13/05 05:11 PM)
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Anonymous
Unregistered
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Look forward to it! Best of luck to you.
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 5618
Loc: San Francisco Bay Area, Calif...
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Christopher Go frequently posts to several lists and forums including the AP-UG list. He uses a C8 on an AP1200 mount.
His images of Jupiter are amazing. Outstanding detail.
http://jupiter.cstoneind.com/
Rich
Edited by Rich N (02/14/05 12:14 AM)
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LesB
Carpal Tunnel
Reged: 12/20/04
Posts: 2512
Loc: Z-Hills, FL
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Seeing conditons didn't seem to be a factor for me until I got above 4" in aperture. (I had several refractors). I just never noticed. I can't help but think that the difference between a C11 and a C9.25 may be harder to discern that one might think given a random sequence various seeing conditions.
I do know from experience that the larger the aperture the more sensitive a scope is to seeing conditions. Could it be that the reported differences between a C9.25 and a C11 could be the result of the larger scope being more sensitive to seeing conditons?
Strictly speculation on my part. I'm getting ready to move into the SCT/MAK realm.
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Your DNA is like an egg timer. When it dings, you're done.
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Anonymous
Unregistered
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If you do the math on C11 vs. C9.25...The C11 gives almost a half magnitude greater pickup of stellar magnitude, about .13 more resolution in arc sec., and about a 20%larger increase in magnification for a given eyepiece as well as the same icrease in "useful" magnification under optimal conditions. On the other hand and in similar ratios the C11 is more prone to longer cooldown time and greater degradation of image from collimation error. If the differences weren't rather significant something tells me that it certainly would be unnecessary for celestron to be making both a C8 and a C9.25 since the ratios between these two are even less discernible.
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sixela
Postmaster
Reged: 12/23/04
Posts: 13991
Loc: Boechout, Belgium
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The C9.25 has a different optical configuration (with a longer tube for its aperture, optical surfaces that are easier to figure well; the configuration also produces a flatter field) and the baffling is better (improving contrast).
The disadvantages compared to its more traditional siblings are a (relatively) smaller unvignetted field and less back focus (which is why Denkmeier Starsweeper focal reducer has a special f/7 version for the C9.25 rather than the f/5 version for the other f/10 SCTs).
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400mm f/4.46 self made Dobsonian on Tom Osypowski equatorial platform
Skywatcher 130mm f/5 BlackLine (finder, widefield scope and solar continuum scope)
Sumerian 250mm f/4.8 Alkaid (as travelscope without platform and on Tom O. platform above).
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