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spongebob@55
sage
Reged: 12/26/11
Loc: Bergen Co. New Jersey
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CPC1100/Light Pollution/ Bigger Finderscope?
#5293946 - 06/28/12 09:12 PM
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Hi Everyone,
I live in a white light pollution area. I can't use a telrad b/c of the light pollution, started with a 6X30 and now have a 9 X 50 Stellavue RACI. Nice optics, but unless I'll looking for a bright planet, M42 or M13 at the zenith, I can't see anything besides bright stars. Although I do use the GOTO, there are times that it is off and I have NO IDEA where the object is! So I was thinking of going 80mm. Specifically, the 80mm Orion ShortTube 80 Refractor Telescope Optical Tube Assembly sold by Amazon / Orion for $99, f/5.0 400mm fl. I have a good diagonal and an extra finder, so I could use it as a grab and go and vacation telescope with a camera mount that I have. I would need an illuminated cross hair eyepiece and somehow to mount it to the SCT (have to figure that out,,, any ideas?).
Antares also has a dedicated 12X80 illuminated finderscope,$280 f/4.4 350mm fl. So I'm leaning toward the Meade 80mm Short tube. Any comments, suggestions, experiences?
Thanks Sbob
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MikeBOKC
Post Laureate
Reged: 05/10/10
Loc: Oklahoma City, OK
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Re: CPC1100/Light Pollution/ Bigger Finderscope?
[Re: spongebob@55]
#5294024 - 06/28/12 10:01 PM Attachment (30 downloads)
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Although I don't use my AT72 refractor as a finderscope, it rides well atop my CPC1100 in rings. You will need a counterweight system though as adding all that weight up top will skew your balance, vreating issues in go to and tracking.
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Patrick
Postmaster
Reged: 05/16/03
Loc: Franklin, Ohio
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Re: CPC1100/Light Pollution/ Bigger Finderscope?
[Re: spongebob@55]
#5294184 - 06/29/12 12:04 AM
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Hi Sponge!
If you need a smaller refractor as a multi-purpose scope, then it's hard to beat the AT72ED APO refractors sold by Astronomics. I have the older version AT66ED (66mm). I use mine on top of my CPC1100, like MikeBokc. Since it's an APO, it makes a very versatile scope and is a lot better optically than a short tube 80 achromat.
Now, back to your comment "Although I do use the GOTO, there are times that it is off and I have NO IDEA where the object is!" When you find that your goto's are off, you can go back to your original alignment stars, or find new ones, and realign your scope using the align button. Several suggestions to getting good alignment are to make sure your tripod is level when you start out, carefully center the alignment stars in a reticle eyepiece (or high power eyepiece...I defocus sufficiently to make sure the alignment star is centered), and always use the up and right key as the final directional buttons to push to center. If you overshoot, go all the way back and do it again. Don't be afraid to use a slower speed when centering.
The other piece of advice is to learn you constellations, and the major stars in them if you don't already know them...it's pretty helpful when looking for alignment stars.
As far as knowing what an object is, have you tried the Identify command in the Utilities menu? It works great. Spend some time and read through the manual...lots of good info in there.
Clear skies,
Patrick
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spongebob@55
sage
Reged: 12/26/11
Loc: Bergen Co. New Jersey
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Re: CPC1100/Light Pollution/ Bigger Finderscope?
[Re: MikeBOKC]
#5295463 - 06/29/12 08:35 PM
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Hi MikeBOKC, could you tell me the hardware which you use to mount the AT72 to your CPC1100? It looks like you use rings instead of the L bracket that included with the scope. Why? Thanks
Bob
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spongebob@55
sage
Reged: 12/26/11
Loc: Bergen Co. New Jersey
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Re: CPC1100/Light Pollution/ Bigger Finderscope?
[Re: Patrick]
#5295483 - 06/29/12 08:54 PM
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Hi Patrick. Whoa, I looked into the AT72ED and it looks sweet, but substantially more $ than the Orion ST80. But the quality looks substantially better too. How do you mount yours to your CPC1100? Do you use the L bracket supplied with the scope or another way e.g. rings? Do you use a 2" diagonal? I'll need a low power 40mm ep to get the 11x and max fov. How would I get an illuminated cross hair e.p.?
BTW, your advice on the high power e.p. and defocusing the image for better alignment is excellent! I was using a 24mm but I did level it with a torpedo bubble level. So now I'll go to a 8mm. Would a digital level be better? Thanks so much for the ideas!
Bob
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Patrick
Postmaster
Reged: 05/16/03
Loc: Franklin, Ohio
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Re: CPC1100/Light Pollution/ Bigger Finderscope?
[Re: spongebob@55]
#5295547 - 06/29/12 09:36 PM
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Bob,
Quote:
I did level it with a torpedo bubble level....Would a digital level be better?
The CPC1100 tripod I have has a built in level on the top. That's what I use before I set the fork assembly on top of it.
Quote:
I looked into the AT72ED and it looks sweet, but substantially more $ than the Orion ST80. But the quality looks substantially better too.
Trust me, $380 for an Apochromatic refractor is a steal. Yes, it's more expensive than the ST-80, but it can do a whole lot more than a short tube 80 achromat...a lot more. Those short tube 80's have so much false color that medium to high power viewing is just about worthless. There's a reason they're so inexpensive.
On the other hand, the AT72ED can actually be used to get somewhat decent views of the planets, and it's good as a stand a lone refractor, imaging scope, or as a finder.
Quote:
How do you mount yours to your CPC1100? Do you use the L bracket supplied with the scope or another way e.g. rings?
I use ADM MDS Components including a top and bottom dovetail plate and two rings on top and a counterweight on the bottom. (I bought my scope used and it came with those components...pretty sweet). The rings are important so that you can more easily align the refractor to the SCT. If you have a hard fixed connection, the scope may not be pointing exactly where you want it and you'll have no way to adjust it.
Yes, I use a 2" diagonal on my CPC1100.
Quote:
How would I get an illuminated cross hair e.p.?
Buy one...  HERE's One
Unfortunately, like most things, astronomy can be an expensive hobby sometimes, at least to get started.
Take care!
Patrick
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spongebob@55
sage
Reged: 12/26/11
Loc: Bergen Co. New Jersey
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Re: CPC1100/Light Pollution/ Bigger Finderscope?
[Re: Patrick]
#5295604 - 06/29/12 10:16 PM
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Hi Patrick.
Yeah, the AT72ED looks great, that's for sure. And using it as a travel scope would definitely be in my plans. Love the components too. But being retired, have to be really sure what to spend the $ on. 
Sorry, I wasn't clear on the question of the 2" diagonal...do you use one on your AT66?
On the illuminated rectile ep, I would be using it as a finderscope in that mode, so it would have to be a 40mm or so.....any knowledge of such an ep at that mm size?
Thanks again. So much good information from you I really appreciate it.
Bob
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Patrick
Postmaster
Reged: 05/16/03
Loc: Franklin, Ohio
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Re: CPC1100/Light Pollution/ Bigger Finderscope?
[Re: spongebob@55]
#5295965 - 06/30/12 07:39 AM
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on the question of the 2" diagonal...do you use one on your AT66?
No, I do not use a 2" diagonal with the AT66ED. I'd need a 2" SCT visual back to make it work with the scope, but don't really need it anyway because the field of view is already pretty large. I use a Televue 32mm 1.25" plossl with the scope giving me 15x and a 3.2° true field of view.
Quote:
On the illuminated rectile ep, I would be using it as a finderscope in that mode, so it would have to be a 40mm or so.....any knowledge of such an ep at that mm size?
No, I'm sorry, I don't. The reason you don't see them at that focal length is because that's not generally how you'd use one.
I'd like to suggest a different approach. I understand about the limited funds and light pollution, so from that perspective, I'd forgo the refractor/finder altogether and spend about $40 on a TELRAD. If you can see bright stars and planets, then that's all you'll need to get a good goto on your CPC1100. If you properly align the Telrad to your scope, you should be able to get those bright stars in a widefield eyepiece in the CPC1100. Do a goto alignment and center the star in the widefield eyepiece, then put in a higher magnification eyepiece and defocus and recenter the star (This is where the illuminated reticle eyepiece would come into play if you had one, but it's not a necessity) and hit the align button. Then go to the next star and align it until you've completed the goto alignment.
The nice thing about a Telrad is that the 3 illuminated circles can be dimmed very dim to make finding dim stars fairly easy. Once you get your scope's goto aligned properly you shouldn't have any trouble finding objects anywhere in the sky. I think that's the real issue you're having.
If you haven't been down to the Nexstar GPS/CPC Telescope Forum (down further in the Forums List) you should check it out. Lots of good advice there on using your scope.
Even though I mount my AT666ED on my CPC1100, I rarely use it as a finderscope...well never really. I use it to give me widefield views of objects that are too large for the CPC1100. I always use my Telrad for doing my goto alignment.
Regards,
Patrick
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MikeBOKC
Post Laureate
Reged: 05/10/10
Loc: Oklahoma City, OK
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Re: CPC1100/Light Pollution/ Bigger Finderscope?
[Re: spongebob@55]
#5296075 - 06/30/12 09:30 AM
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I attached a Losmandy D plate to the top of the tube. Then bolted the rings to these:
http://www.astronomics.com/main/product.asp/catalog_name/Astronomics/category_name/LR9U6B1PVMKS8MQ86B8UEBQW85/product_id/ATDAB
Slide them on from the front of the dovetail and tighten. Very stable and allows fine tuning to center the object and align it with the telescope view, which makes it equivalent to a finderscope.
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spongebob@55
sage
Reged: 12/26/11
Loc: Bergen Co. New Jersey
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Re: CPC1100/Light Pollution/ Bigger Finderscope?
[Re: MikeBOKC]
#5297098 - 06/30/12 11:01 PM
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Could I use the Celestron 80mm Guidescope Package 52309 optically if I added a mirror diagonal? Looks like a nice package. I could add my extra diagonal, etc and have a nice quide/finder/GOTO scope, if the quality is good.... How's the CA on this? Any idea?
Thanks
bob
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spongebob@55
sage
Reged: 12/26/11
Loc: Bergen Co. New Jersey
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Re: CPC1100/Light Pollution/ Bigger Finderscope?
[Re: Patrick]
#5643177 - 01/25/13 07:08 PM
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Hi Sponge!
If you need a smaller refractor as a multi-purpose scope, then it's hard to beat the AT72ED APO refractors sold by Astronomics. I have the older version AT66ED (66mm).
Clear skies,
Patrick
Hey Patrick,
Do you know if the AT72ED has a collimatable objective? couldn't find that on the Astronomics site. Not that its in stock!!
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