Phil Hosey
sage
Reged: 10/29/08
Posts: 353
Loc: LaGrange, GA
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Hey guys,
I was thinking of getting a small APO for double duty as a guidescope for my SN10 as well as a short FL scope for imaging and would like some recommendations, especially if you know of any that are currently on sale. I sort of want to keep it as inexpensive as possible without sacrificing too much for imaging. Is 80mm the minimum for imaging or can you get good results with a 66mm or 70mm?
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Yedgy
professor emeritus
Reged: 07/22/08
Posts: 601
Loc: Phoenix, AZ, USA
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Phil, 66mm or 70mm are fine for both guiding and widefield imaging. I'm happy with my 70ED. If you keep your guidescope aligned with the SN10 you can even use it as a finderscope with a nice long FL eyepiece. Good scopes in this range can be found new for around $400 and even less if they're used.
Tony
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The Universe is an awesome place. I'm glad I live here.- Takahashi FS-60CB
- Takahashi FSQ-106EDXIII
- HyperTuned Atlas EQ-G
- Mountain Instruments MI-8P pier
- Spectrum-Enhanced Canon EOS 450D
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RandallK
Pooh-Bah
Reged: 11/10/06
Posts: 1077
Loc: Nanaimo, B. C. Canada
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Anyone using the Orion Short Tube 80?
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Scopes: Meade SC-8AT w UHTC
Orion ST-80 Refractor (Autoguiding)
SkyWatcher 5" F/5 Reflector
SkyWatcher 127mm MAK
Mount: HEQ5 Pro
Cameras: Orion Starshoot DS Colour Imager V.1
Imaging Source Webcam DMK21AU04.AS
Canon XSi 450D Unmodded
Palm TX PDA w Astromist and Bluetooth wireles control.
Oh yeah..and the ACME Cloud Destroyer!!
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Yedgy
professor emeritus
Reged: 07/22/08
Posts: 601
Loc: Phoenix, AZ, USA
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The Orion ST80 makes a fine guidescope but the OP wants to image with it, too. The ST80 is an achromat and thus not really suitable for imaging.
Tony
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The Universe is an awesome place. I'm glad I live here.- Takahashi FS-60CB
- Takahashi FSQ-106EDXIII
- HyperTuned Atlas EQ-G
- Mountain Instruments MI-8P pier
- Spectrum-Enhanced Canon EOS 450D
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MartyT
professor emeritus
Reged: 09/28/07
Posts: 682
Loc: Kansas City
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You can do a lot of (very) wide field imaging with a 66mm APO - something like a William Optics ZS66SD works great and was the scope I started out with. But be aware that the field of view is really pretty wide - making it difficult to image anything that's not very big. On the other hand, the wide FOV is a lot more forgiving of polar alignment error, bad seeing and other problems.
You might want to tinker with CCDCalc http://www.newastro.com/book_new/camera_app.php - you can punch in the particulars of the scope and camera you're using and it'll show a simulated field of view for hundreds of Messier and NGC objects. I use it quite a bit to get an idea of what kinds of objects will frame well with my imaging setup.
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Celestron CGE / C-11 (CGE-1100)
Megrez 90 FD APO / 0.8x FR/FF vIII
QHY8, 350D, DSI Pro, SPC900NC
KWIQ Guider (QHY5)
ETX-125AT
12" Lightbridge
My Astrophoto Gallery
Astronomical Society of Kansas City
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RandallK
Pooh-Bah
Reged: 11/10/06
Posts: 1077
Loc: Nanaimo, B. C. Canada
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I agree, Ron Wodaski's program is the cat's meow! I have been looking the WO66 but waiting 'till after Christmas. The Orion Short Tube (without the diagonal) is my 2nd choice. Right now I'm using my DMK webcam with my Antares 7 x 50 finderscope in tandem with an Antares 2X Barlow (with the lens removed). It doesn't take much to bring it in to rough focus on a guide star, but something with a focuser would be much easier, plus I wouldn't mind getting some wide field shots.
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Scopes: Meade SC-8AT w UHTC
Orion ST-80 Refractor (Autoguiding)
SkyWatcher 5" F/5 Reflector
SkyWatcher 127mm MAK
Mount: HEQ5 Pro
Cameras: Orion Starshoot DS Colour Imager V.1
Imaging Source Webcam DMK21AU04.AS
Canon XSi 450D Unmodded
Palm TX PDA w Astromist and Bluetooth wireles control.
Oh yeah..and the ACME Cloud Destroyer!!
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DaemonGPF
Post Laureate
Reged: 03/22/08
Posts: 4039
Loc: New Mexico
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Quote:
Anyone using the Orion Short Tube 80?
NyxAither (Thomas) is using an ST-80 as a guidescope right now.
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-Josh
http://cleardarksky.com/c/AlbuqNMkey.html
My AP Gallery
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Phil Hosey
sage
Reged: 10/29/08
Posts: 353
Loc: LaGrange, GA
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Quote:
Phil, 66mm or 70mm are fine for both guiding and widefield imaging. I'm happy with my 70ED. If you keep your guidescope aligned with the SN10 you can even use it as a finderscope with a nice long FL eyepiece. Good scopes in this range can be found new for around $400 and even less if they're used.
Tony
I hate to ask such a basic question, but what hardware would I need to mount such a scope on my SN10? I want to make sure I get all the pieces I need so I can begin using is right away.. I hate getting stuff only to find out I need even more stuff to make it work.
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DaemonGPF
Post Laureate
Reged: 03/22/08
Posts: 4039
Loc: New Mexico
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There's a few ways to go about it, but if you plan to mount it on top of the SN10, you will need a set of guidescope rings with adjustable thumbscrews, and another dovetail/guidescope ring mounting bar.
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-Josh
http://cleardarksky.com/c/AlbuqNMkey.html
My AP Gallery
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Phil Hosey
sage
Reged: 10/29/08
Posts: 353
Loc: LaGrange, GA
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Quote:
There's a few ways to go about it, but if you plan to mount it on top of the SN10, you will need a set of guidescope rings with adjustable thumbscrews, and another dovetail/guidescope ring mounting bar.
Ok, as of right now I have a 13" Vixen style dovetail bar that my SN10 rings are currently attached to. Since I'm upgrading the saddle on my Atlas and the dovetail to the Losmandy style stuff, could I use the 13" Vixen dovetail bar on the top of the SN10's rings and mount the guidescope rings on that? I guess I'm just not sure which pieces will work woth what since I don't have it all in front of me.
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Phil Hosey
sage
Reged: 10/29/08
Posts: 353
Loc: LaGrange, GA
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Ok, I think I have the guidescope mounting thing figured out. Now all I have to do is decide which OTA to get and that seems to be driving me crazy. I'm sort of leaning toward the SV70ED at the moment. How is the color correction on these for imaging purposes?
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Astro-Tech 8" f/4 Imaging Newtonian
Stellarvue SV102ED
William Optics Zenithstar 70ED
Orion Atlas EQ-G / EQMOD
Canon 450D / Baader UV/IR cut filter mod
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Yedgy
professor emeritus
Reged: 07/22/08
Posts: 601
Loc: Phoenix, AZ, USA
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It's pretty good, on par with other 66-70 scopes in that price range. It's definitely not an APO (nor does Stellarvue market it as such), but it's fine for wide fields. BTW, SV's guidescope rings are pretty solid.
Tony
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The Universe is an awesome place. I'm glad I live here.- Takahashi FS-60CB
- Takahashi FSQ-106EDXIII
- HyperTuned Atlas EQ-G
- Mountain Instruments MI-8P pier
- Spectrum-Enhanced Canon EOS 450D
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Phil Hosey
sage
Reged: 10/29/08
Posts: 353
Loc: LaGrange, GA
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I forgot to mention that I will be guiding visually.. that is, no autoguider. Won't these scopes been too short to guide a main scope of 1016mm manually?
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Yedgy
professor emeritus
Reged: 07/22/08
Posts: 601
Loc: Phoenix, AZ, USA
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Phil, if you want to guide manually you can either go with a longer guidescope like Orion's 80mm f/11.4 unit or use a barlow/PowerMate to increase the focal length of your guidescope.
Mind if I ask why you want to guide manually?
Tony
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The Universe is an awesome place. I'm glad I live here.- Takahashi FS-60CB
- Takahashi FSQ-106EDXIII
- HyperTuned Atlas EQ-G
- Mountain Instruments MI-8P pier
- Spectrum-Enhanced Canon EOS 450D
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blueman
Vendor Blue Sky Accessories
Reged: 07/20/07
Posts: 1803
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Manual guiding is tedious to say the least. You will have a sore neck and back before your first image is done. 
IT is not impossible, but I can tell you that it is not fun or easy.
Auto guiding is the only way in my opinion.
Blueman
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14.5" Starmaster with ServoCat and Argo Navis
1966 Unitron 4" Model 152 EQ
AT 8" RC
TV NP101 f/5.4 APO Telvue .8 Focal Reducer
FLI ML8300 and CFW-2-7 filter wheel
FLI RGBL 2" filters Baader 2" Narrow Band Filters
SBig ST2000xm with CFW-9 filter wheel
Astrodon Gen2 filters RGBL
Baader HA,O-III, H-Beta, S-II Filters
ST80 Guide Scope Orion SSAG Guide Camera
Losmandy G-11 Gemini Auto-guided
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Phil Hosey
sage
Reged: 10/29/08
Posts: 353
Loc: LaGrange, GA
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Quote:
Phil, if you want to guide manually you can either go with a longer guidescope like Orion's 80mm f/11.4 unit or use a barlow/PowerMate to increase the focal length of your guidescope.
Mind if I ask why you want to guide manually?
Tony
Tony,
The main reason I want guide manually is because I don't have a laptop and my budget is pretty much shot for a while. I figure I could guide manually until I can afford an autoguider setup. I'm sort of putting my AP setup together peice by piece, only I want to get some use out of the pieces before I actually have everything together. I messed up and spent all my money on the big OTA and the mount when I *should* have started with a small ED refractor and I could have used a smaller mount, then I would have had enough left over for all the 'one more things' that have come up.
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Yedgy
professor emeritus
Reged: 07/22/08
Posts: 601
Loc: Phoenix, AZ, USA
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Blueman is right. Manual guiding will surely make you appreciate an autoguider! You might want to consider starting off with unguided wide-field shots through the smaller scope until the piggy bank is ready for a laptop/autoguider. With an accurate drift alignment, you might be able to get reasonable length subs without any field rotation. With dead-on polar alignment, you might even be able to take 2-3 minute subs with the SN10.
Tony
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The Universe is an awesome place. I'm glad I live here.- Takahashi FS-60CB
- Takahashi FSQ-106EDXIII
- HyperTuned Atlas EQ-G
- Mountain Instruments MI-8P pier
- Spectrum-Enhanced Canon EOS 450D
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groz
Pooh-Bah
Reged: 03/14/07
Posts: 1288
Loc: Duncan, BC
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Quote:
I agree, Ron Wodaski's program is the cat's meow! I have been looking the WO66 but waiting 'till after Christmas. The Orion Short Tube (without the diagonal) is my 2nd choice. Right now I'm using my DMK webcam with my Antares 7 x 50 finderscope in tandem with an Antares 2X Barlow (with the lens removed). It doesn't take much to bring it in to rough focus on a guide star, but something with a focuser would be much easier, plus I wouldn't mind getting some wide field shots.
I've got the skywatcher branded ST80, identical to the orion cept for the paint. Works ok as a guider, but, the focuser has issues. With the webcam in there, it needs an extender to reach focus without the diagonal, and, by the time the extender is on, there's a considerable amount of slop in the whole arrangement. That translates into flex as the system slews.
We have the ST80 twinned side by side with a williams zenithstar 80. Visually, the difference between them is dramatic, the ST80 shows nice neat neat stars, with the blue halos of an achro. The Williams shows nice pinpoints on the same starfield. The guidecam stuck in them side by side 'sees' quite a difference too. On the same starfield, in the williams it reaches at least a full magnitude dimmer than the ST80, and I suspect that's because the doublet gives better focus on the guide chip, nice pinpoints without the blue halo equals more light on a single pixel.
Using a webcam type camera for guiding, this makes a huge difference on what you can lock into for guide stars. We put a dsi-pro into it, so the difference isn't so big of an issue for us, the dsi-pro on 1 or 2 second exposures can reach pretty deep into a starfield and lock onto pretty dim stars.
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mclewis1
Thread Killer
Reged: 02/25/06
Posts: 4476
Loc: New Brunswick, Canada
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Quote:
Quote:
There's a few ways to go about it, but if you plan to mount it on top of the SN10, you will need a set of guidescope rings with adjustable thumbscrews, and another dovetail/guidescope ring mounting bar.
Ok, as of right now I have a 13" Vixen style dovetail bar that my SN10 rings are currently attached to. Since I'm upgrading the saddle on my Atlas and the dovetail to the Losmandy style stuff, could I use the 13" Vixen dovetail bar on the top of the SN10's rings and mount the guidescope rings on that? I guess I'm just not sure which pieces will work woth what since I don't have it all in front of me.
Phil, if you flip the rings over and have that vixen bar at the top you can get a pair of Losmandy rings (part #VR90 - $89) that have the vixen compatible saddles built right in. You'll have complete flexibility in terms of length of guide scope (just move the rings to fit the scope). Depending on the width of the ST80 tube you might need to go up one size in rings (VR108), but that 70mm will likely be fine in the smaller rings.
No muss, no fuss, complete and ready to go.
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Mark
C11, C6, APM/TMB115, and AT80ED - Tandem mount CGE and CG-5A, WO EZ-Touch and AT Voyager
25x100s and 8x56s, T-Mount Light, Mark 1 eyeballs - Modded 350D, DSI-P, SPC900, Mallincam
Just because you can doesn't necessarily mean that you should
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