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I need your help for this decision

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#1 bilgebay

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Posted 30 January 2013 - 04:35 PM

I want to go down to C8 Edge from C11 Edge. My reasons are:

- Since I don't have a permanent setup, I am finding it quite cumbersome and risky to move this OTA in and out in my 2 storey warm room - observation terrace setup. I feel even more uncomfortable when I have the Hyperstar + CCD/DSLR hanging off of the corrector plate. I am keeping the dew shield on the scope during these transports to provide some sort of protection lest I should hit the camera against a door or a tree but this makes the scope even bulkier.

- I have acquired several other scopes after I purchased this scope. If you look at my signature you can see these scopes. By the way, the scope list is in chronological order according to the purchase date. When I purchased my C11 Edge, the idea was to use this scope both for visual and imaging. But now, I have larger aperture scopes for visual. Additionally, I have ordered 2x Zambuto mirrors for my 12" Dob and 8" Newt. I am sure 12" Zambuto mirror, coupled with a quality secondary and Feather Touch focuser + Paracorr II will give C11 Edge a hard time.

- In the meantime, I have moved to CCD imaging from DSLR imaging and purchased an Atik 460 EX with very convenient form/size which will not intrude into the light path of C8 when imaging in the Hyperstar configuration. So I don't need a C11 Edge just to make up for the bulkiness of the DSLR body.

- I am aware that the focal length will go down from 2800mm to 2032mm at f/10 and from 560mm at f/2 to 425mm. On the other hand I will have a wider FOV which I actually like.

Do you see a problem in this, other than losing some focal length, from an astro imagers point of view? I will have a much compromised performance if I want to use this scope visually, no doubt.... but this is not my primary concern now.

#2 AstroGabe

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Posted 30 January 2013 - 04:50 PM

I was on the fence between the C8 Edge and C9.25 Edge. I decided on the C9.25 due to the longer backfocus (same as your C11 Edge) that would allow me to implement an adaptive optics unit. More room for expansion. There was a slight hesitation though since the C8 Edge has a focal reducer coming out in the next few months. In the meantime, I'll try the AP CCDT67 reducer.

I'd say if you are fine w/ shorter backfocus, then go for it.

Gabe

#3 bilgebay

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Posted 31 January 2013 - 06:31 AM

Thank you Gabe. You have a valid point... let me check the back focus issue...

Any further comments by the experts! Do you think I am crazy ? :lol:

#4 Mark72

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Posted 31 January 2013 - 06:34 AM

Sedat,

Just leave it in on the terrace.
Mine is on the balcony, never moved.

Mark

#5 bilgebay

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Posted 31 January 2013 - 06:55 AM

:) Mark, good idea... but I am there only during weekends.. weekdays I am 500 miles away :(

#6 mmalik

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Posted 31 January 2013 - 09:52 AM

Scopes: C5, A80SS, C11 Edge HD + Hyperstar, AT65EDQ, Lunt LS80THa/PT/B1800/FT, Mini Borg 50 mm, TMB-92 SS, SVP 8", Lightbridge 16", FSQ106EDX, Orion SQ XT12i
Mounts: Vixen New Atlux, controlled via NexAtlux, Vixen Polarie, Astrotrac TT320X-AG


Sedat, I am not even familiar with most of the stuff you have from scopes to mounts. Since you don't seem to be visually inclined anymore, I would suggest cleaning house with the exception of FSQ106EDX; you could channel your recouped funds into a high-end 130-140mm APO for photo-visual use. If you'll be doing imaging primarily, you could also look into salvaging/consolidating your mount platform as well to something like Mach1/900GTO. Again, I don’t know most of your current equipment, so use your discretion accordingly. Thx

#7 korborh

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Posted 31 January 2013 - 10:19 AM

If you don't intend to take advantage of the C11 Edge focal length for high-res/planetary work, then moving to C8 makes sense given your other described constraints.

#8 Mark72

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Posted 31 January 2013 - 12:43 PM

Sedat,

So do I. So what ;)
I just put a cover on it and that it.

Mark

#9 Peter in Reno

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Posted 31 January 2013 - 01:23 PM

I also went from standard C-11 to C-8 and now C-8 EdgeHD. You are correct that C-11 is a lot to handle and I find C-8 EdgeHD very pleasant to use.

Notice that the back focus for C-8 EdgeHD is 133mm at F/10. BUT with the new C-8 EdgeHD focal reducer coming, the back focus was REDUCED to 105mm. I was not happy about this. Fortunately my imaging train will work. When I read that C-11/C-14 EdgeHD maintained the same back focus with or without focal reducer, I assumed Celestron would do the same for C-8 EdgeHD but they didn't. It would have been convenient to keep the same imaging train at F/10 and F/7 so I would not have to take apart and re-assemble the imaging train to set proper back focus distance.

I wanted to buy an ONAG which will work with 133mm back focus at F/10. But the minimum back focus I can do with my Atik 460EX (same as yours), Lodestar, SX Filter Wheel and ONAG is 120mm. That's 15mm over than 105mm spec for C-8 EdgeHD focal reducer. So I decided not to get ONAG.

When I get a C-8 EdgeHD focal reducer, I may plan to test it with 120mm back focus and see if there will be negative effects. If there will not be any negative effects, then I may get an ONAG.

C-8 EdgeHD is a great scope and not much of a loss from C-11.

Peter

#10 bilgebay

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Posted 01 February 2013 - 02:19 PM

Hi Peter, thank you for your comments. Since I am not planning to use ONAG with this configuration, the back focus seems to be more than enough for my imaging trains.

Clear skies

Sedat

#11 bilgebay

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Posted 01 February 2013 - 03:24 PM

Sedat,

So do I. So what ;)
I just put a cover on it and that it.

Mark


Mark, unfortunately, I cannot leave my stuff outside for extended periods. The climate can be very harsh at times, hale storms and winds reaching 70 miles are not very uncommon especially during winter. Additionally, all sorts of wild creatures are around, from bugs to wild boars. I may also have unfriendly visitors from time time. This is mainly the reason for not building a lightweight shelter for the scope. If I am going to build something, it must be really strong but then I don't want to do that on my terrace. It is much more spacious like this and better suits to the environment.

Maybe, I can explain my situation with some photos:

In this first photo, my Vixen New Atlux mount is seen on the pier in the foreground. In the background, we are preparing my friend, Ozzy's AP1200 mount and C14 Edge Scope for the first light.

Posted Image

Click here for hires photo

Mounting C14 on the AP1200 is very easy, using Greg's method.
Posted Image

Posted Image

Click here for hires photo

My C11 Edge is also mounted now. Ready for the evening.
Posted Image

Click here for hires photo



I love this open Sky Theatre and I don't want to imprison my self and the scope inside a very limited space there.

Posted Image

Click here for hires photo

Posted Image

Click here for hires photo

Posted Image

#12 bilgebay

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Posted 01 February 2013 - 03:29 PM

Scopes: C5, A80SS, C11 Edge HD + Hyperstar, AT65EDQ, Lunt LS80THa/PT/B1800/FT, Mini Borg 50 mm, TMB-92 SS, SVP 8", Lightbridge 16", FSQ106EDX, Orion SQ XT12i
Mounts: Vixen New Atlux, controlled via NexAtlux, Vixen Polarie, Astrotrac TT320X-AG


Sedat, I am not even familiar with most of the stuff you have from scopes to mounts. Since you don't seem to be visually inclined anymore, I would suggest cleaning house with the exception of FSQ106EDX; you could channel your recouped funds into a high-end 130-140mm APO for photo-visual use. If you'll be doing imaging primarily, you could also look into salvaging/consolidating your mount platform as well to something like Mach1/900GTO. Again, I don’t know most of your current equipment, so use your discretion accordingly. Thx


Mike, on the contrary, I have better visual scopes now like the dobsonians; Meade Light Bridge 16" and an Orion XT12" with a Zambuto mirror.

I am extremely happy with my mount, there is nothing wrong with the mount. You can load it upto 45 lbs for imaging and still get nice, round stars at 2800mm focal length.

Thanks

#13 bilgebay

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Posted 01 February 2013 - 03:31 PM

If you don't intend to take advantage of the C11 Edge focal length for high-res/planetary work, then moving to C8 makes sense given your other described constraints.


Hi korborh,

Yes, this is what I am thinking at the moment.

Clear skies

Sedat






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