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9.25 or 11" edge hd or at10rc?

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#1 powerstroke01

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Posted 13 February 2013 - 11:59 PM

I have a hypertuned losmandy g11. I will be using the new scope for photographic purposes only.
Which of these 3 would be the vbetter choice and why?

#2 KDizzle

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Posted 14 February 2013 - 12:13 AM

at10rc pros: backfocus, excellent thermal stability, minimal dew issues.
at10rc cons: collimation is unpleasant. field is not perfectly flat for large chips.
edge pros: super flat field, can run hyperstar for super wide field, easier collimation
edge cons: dew, cruddy backfocus distance which is also exacting

so get the cdk 12.5.

#3 orlyandico

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Posted 14 February 2013 - 12:43 AM

a cdk12.5 is quite costly and a G11 won't carry it.

between the choices I'd go with the 11 EDGE.

there is no 0.7X reducer for the 9.25 EDGE yet, but if there were the 9.25 (or even the 8) are less bulky. if doing hyperstar however the 11 is a better choice as you need all the focal length you can get.

#4 powerstroke01

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Posted 14 February 2013 - 02:30 PM

Thanks. Im really liking the 11" Edge..

#5 Escher

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Posted 14 February 2013 - 03:16 PM

Do you plan to possibly go with Hyperstar? If so, just get the standard C11 as there is no benefit of the Edge system for hyperstar use... (The edge correctors are in the rear baffle, not used with hyperstar).

#6 powerstroke01

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Posted 14 February 2013 - 05:15 PM

man. I just dont know anymore. ahha
I want to go hyperstar but i really like the idea of not having a moving mirror. THats the whole reason im getting rid of my meade 10"

#7 powerstroke01

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Posted 14 February 2013 - 09:59 PM

Anyone else? THe price of the FR for the 11" edge is a major turn off. :(

#8 jrcrilly

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Posted 14 February 2013 - 10:06 PM

i really like the idea of not having a moving mirror. THats the whole reason im getting rid of my meade 10"


That's a strong point for the RC. Between that and the cooling and dew issues it was easy for me to move away from SCTs.

#9 powerstroke01

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Posted 14 February 2013 - 10:36 PM

i really like the idea of not having a moving mirror. THats the whole reason im getting rid of my meade 10"


That's a strong point for the RC. Between that and the cooling and dew issues it was easy for me to move away from SCTs.

Yeah thats why i love the idea of an RC..
BUT! could i live with the 2000mm f/l?? I cant find any info on a reducer for the at10rc... So im guessing one is not available? Im so torn here. :question:

#10 powerstroke01

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Posted 14 February 2013 - 10:39 PM

Another question i have, what about dew on the at10rc? I have a dewbuster. But im wondering how one would combat dew on the RC??

#11 jrcrilly

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Posted 14 February 2013 - 10:41 PM

BUT! could i live with the 2000mm f/l?? I cant find any info on a reducer for the at10rc... So im guessing one is not available? Im so torn here. :question:


I never considered a reducer; for me, the whole point of a Cass variant is to achieve 2000mm or more in a manageable package. If I wanted to shoot at shorter focal lengths I'd select some other configuration.

#12 jrcrilly

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Posted 14 February 2013 - 10:44 PM

Another question i have, what about dew on the at10rc? I have a dewbuster. But im wondering how one would combat dew on the RC??


I used to have real dew problems with various SCTs and refractors. With the RC's open tube and fans I've never had an issue.

#13 powerstroke01

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Posted 14 February 2013 - 10:46 PM

BUT! could i live with the 2000mm f/l?? I cant find any info on a reducer for the at10rc... So im guessing one is not available? Im so torn here. :question:


I never considered a reducer; for me, the whole point of a Cass variant is to achieve 2000mm or more in a manageable package. If I wanted to shoot at shorter focal lengths I'd select some other configuration.

True. Ive got my at65edq for wide field. But id like something else in the 1000-1200mm range too. Hmm.
I really do like the 10" RC..

#14 powerstroke01

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Posted 14 February 2013 - 10:52 PM

Another question i have, what about dew on the at10rc? I have a dewbuster. But im wondering how one would combat dew on the RC??


I used to have real dew problems with various SCTs and refractors. With the RC's open tube and fans I've never had an issue.

Interesting. I would think dew would be more of an issue because it is open. My buddies orion 8" astrograph scope dew'd up bad the other night. THats why i ask.

#15 jrcrilly

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Posted 14 February 2013 - 11:13 PM

I would think dew would be more of an issue because it is open. My buddies orion 8" astrograph scope dew'd up bad the other night. THats why i ask.


I've had Newt secondaries dew up, but never primaries. Keeping the air moving in the RC tube seems to keep the secondary clear.

#16 jrcrilly

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Posted 14 February 2013 - 11:15 PM

But id like something else in the 1000-1200mm range too.


That's midsize refractor territory, and a very useful range. It does mean keeping a third OTA on hand. I just sold my TOA-130 so I have a gap there but I'll pick up another refractor sooner or later.

#17 powerstroke01

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Posted 14 February 2013 - 11:44 PM

But id like something else in the 1000-1200mm range too.


That's midsize refractor territory, and a very useful range. It does mean keeping a third OTA on hand. I just sold my TOA-130 so I have a gap there but I'll pick up another refractor sooner or later.

yeah. Thats probably what ill do as well.

Thanks for all the help.

#18 mega256

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Posted 15 February 2013 - 12:34 AM

I just bought a C11-hd...Its a very nice scope..
I had a 8" RC and still have a 6"RC..I realy like the RC scopes for photo work....But I live in humid Florida
and open tubes tend to need cleaning because of dew and damp
conditions...When it came time to put over 3k in a scope,I got the C11-hd,the closed tube helps a lot to keep the mirror clean and cleaning the corrector is easy. But a closed tube type RC is very difficult for me to clean,it has to be taken apart and I didn't want to go through the alignment
system.Open (trust type ) RCs are $$$...but you can get to the primary for cleaning....But having both I think the optics in the RCs are just great.

#19 pfile

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Posted 15 February 2013 - 02:49 AM

i have an at10rc and a G11, albeit stock worm and not hypertuned.

i just gave up and got a mach1gto. imaging at that FL was not impossible with the G11 but i had to throw away a lot of subs.

and i had to throw away 100% of subs until i started using an OAG.

#20 powerstroke01

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Posted 15 February 2013 - 08:32 AM

i have an at10rc and a G11, albeit stock worm and not hypertuned.

i just gave up and got a mach1gto. imaging at that FL was not impossible with the G11 but i had to throw away a lot of subs.

and i had to throw away 100% of subs until i started using an OAG.

I've got the ovision worm as well.
I'm just wondering though, I'm currently imaging at 1500mm and not throwing away any subs. Would that change going up 500mm? I mean I'd be using the same guide scope. So I'd think my guiding would stay the same.

#21 pfile

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Posted 15 February 2013 - 12:17 PM

i believe the AT10RC is particularly susceptible to focuser-related flexure, or rather, mirror shift. it turns out that the 'back' of the telescope (where you attach the focuser) is actually attached to the primary mirror itself. so with the weight of all the stuff hanging off the OTA the mirror can shift as the forces change during the night (as the OTA moves)

so, part of my problem was unguidable periodic error and part was the OTA. however with the mach1gto i managed a 5 minute unguided exposure of the running man that looked like my best guided exposures with the G11/OAG - slightly oblong stars in RA. guided exposures -> perfectly round stars.

another thing is that it can be difficult to get the focuser square with the optical axis of the AT10RC. some people use this tilt/tip ring that teleskop-service sells to line things up. my moonlite focusers have a tilt adjustment but i have not gotten that far yet.

also i believe a high-quality focuser for the AT10RC is mandatory. the included focuser just does not cut it, and anyway you'll want one that can can be computer-controlled.

#22 jrcrilly

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Posted 15 February 2013 - 01:01 PM

also i believe a high-quality focuser for the AT10RC is mandatory. the included focuser just does not cut it, and anyway you'll want one that can can be computer-controlled.


There appears to be some variability in the stock focusers. I was amazed at how good the one on my 10" was; changed it out rather than fabricate a stepper bracket only because I had a stepper-equipped Moonlight lying around.

#23 orion61

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Posted 15 February 2013 - 03:57 PM

10 RCX are super but some had focus/collimation issues, try it before you buy it..
otherwisw Edge 11 all the way!






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