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larger companion to a 5" triplet

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#1 moonnerd

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Posted 08 July 2014 - 05:08 PM

I have a 5" triplet refractor that I love, and am thinking about getting a larger companion for it. 99% of my observing is from my backyard, all of it visual, 80% lunar and planetary with the rest being Messier objects.

My other favorite scope was a 6" Mak Newt that I had to sell a few years ago. The reason I would want another scope would be hunting smaller features on the moon than are visible to a 5 inch, and for planetary views when there is good seeing.

Would a C8 be enough of a jump up or would it need to be at least a 9.25? I would love a Mak but a 7" would be as big as I could go, and I don't know if thats enough of a jump. I have often thought about Ed's strategy of getting a larger intelliscope and possible having the mirror refigured. Any other thoughts?

cheers -
Rob

#2 KerryR

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Posted 08 July 2014 - 05:24 PM

I think you're going to have to go larger than an 8" reflector if you're going to make a -significant- gain in reach over your 5" refractor, assuming good to excellent optics there. I'd suggest a 10" Dobsonian if you're not averse to Newts. Seeing becomes considerably more critical as aperture goes up, so you may find you don't resolve much more detail through the 10. Messier's, though, will be a different experience.

#3 moonnerd

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Posted 08 July 2014 - 06:02 PM

Thanks Kerry. I agree. I think the 10" might be the sweet spot of portability vs extra aperture. I've been reading with interest the thread about largest size for portability on the reflector forum. Thanks again!

#4 Stelios

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Posted 08 July 2014 - 06:20 PM

I'd advise a C9.25 or C11 rather than a 10" DOB, assuming the advantages of the SCT (tracking, GoTo, comfortable observing) are important to you. The longer F/L of the SCT comes in handy for lunar, planetary and double star observing, as well as for all but the largest Messier showpieces.

Despite avowals by the aficionados, I've never felt comfortable with nudge-based high-power observing. I'm actually quite good at it, having joined the hobby in an era when tracking was a luxury I couldn't afford, but I don't enjoy it, and when my attention is on re centering the object it never gets fully focused on eking out the finest details.

#5 jgraham

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Posted 08 July 2014 - 06:38 PM

An 8" SCT would make a great companion to a 5" refractor (I own a 6" f/8 achro), a nice step up, but not huge. A 10" SCT would be a very nice step, but for some there is a big increase in weight between an 8" and 10" SCTs. (And yes, I have both.) For maximum portability I'd consider an 8", but if the weight and cost weren't a problem a 10" SCT is a wonderful scope. Either way, I'd also toss in a Lymax Cat Cooler or equivalent if you want to routinely do high resolution observing. Refractors can really spoil you for fast cool-down times.

#6 Bill Barlow

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Posted 08 July 2014 - 08:13 PM

As far as SCT's go, to get a significant increase in performance over your 5" refractor, I would go at least to the C9.25 as it weighs only 20 pounds or a C11 if you/and your mount can handle the 28-30 pound weight. What 5" triplet do you own? Good luck with your choice!

#7 stevew

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Posted 08 July 2014 - 08:44 PM

I'm nothing more than a casual Lunar observer, but I do own a 5 inch triplet, and a few SCT's,
and I can tell you that on the planets I can see a similar amount of details in the C8 that I can see in the 5 inch.
If I really want to see planetary details I'll pull out the C11, and it trumps the 5 inch triplet for resolution as would be expected.
Hope this helps.

Steve

#8 mnshanny

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Posted 08 July 2014 - 08:56 PM

c11edge, my combination with an AP1100 and ES 127ED

#9 Alan S

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Posted 08 July 2014 - 09:10 PM

Same here....11 inch edge, along with a 140mm refractor...pure bliss.

#10 moonnerd

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Posted 08 July 2014 - 10:04 PM

Thanks for all your great replies. I'm spoiled by the sharpness of Mak Newts and triplets, so how would the sharpness of a C11 Edge compare?

BTW Bill, my refractor is a Stellarvue 130EDT. Its an FPL-51 scope, but with great optics. The seeing isn't great where I live, so its a good fit.

#11 dr.who

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Posted 08 July 2014 - 10:18 PM

A 5" refractor is like a 6.5-7" SCT so you need to go to at least the 9.25 to get into the complementary zone instead of the completion one. If you are spoiled from refractor views then you will want the Edge series. Properly cooled you get close to refractor views.

For cooling invest in the Deep Space Products Tempest fan system. It should be mandatory on Edge SCT's since it cuts cool down in half and keeps equilibrium while viewing.

If your skies aren't great then the 11" may be disappointing since you need good skies to maximize its potential. Of course when those good skies happen the scope sings! Mine did. Both the 9.25 and 11 Edge's will work fine for visual on an AVX mount as will that SV if you need a mount.

#12 areyoukiddingme

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Posted 08 July 2014 - 10:23 PM

Another vote for the 11 edge. . . but for visual only, you've got to consider a 12" dob. Central obstruction will be smaller/contrast better, and with a premium mirror deep sky and planets will be excellent. Plus cooling will be less of an issue.

#13 Spacetravelerx

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Posted 09 July 2014 - 12:37 AM

Each has there larger companion combo.

For my 130mm ED APO it is the Meade 14" f/8 ACF. Absolutely stunning views out of this baby.

Based on the excellent quality and out of box performance and features of the 14" I am purchasing the 10" f/8 ACF for a more portable system and another complement with my 130mm.

On the LX850 mount I will be going with the 10" f/8 and the 130mm side by side. The mount can handle this combo weight wise and no need to add any extra mounts plates.

Edge is over priced for pure visual.

Dob's are also fun for our visual. Meade has a sale on them right now. Dobs are certainly great bang for the buck on the visual front from any brand. 12" seems to be a sweet spot in Dobs for "big" mirrors, but still portable. The really big ones - you will need to bring a ladder! ;)

#14 dweller25

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Posted 09 July 2014 - 12:54 AM

I'm nothing more than a casual Lunar observer, but I do own a 5 inch triplet, and a few SCT's,
and I can tell you that on the planets I can see a similar amount of details in the C8 that I can see in the 5 inch.
If I really want to see planetary details I'll pull out the C11, and it trumps the 5 inch triplet for resolution as would be expected.
Hope this helps.

Steve


I also have a 5" APO and totally agree with what Steve has said above, but would add that a good 10" Newtonian will also outperform the 5" APO.

#15 Spacetravelerx

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Posted 09 July 2014 - 01:03 AM

I would hope a C11 (M10) would trump a 5" triplet.

Just to add, I love my APOs, but side by side against my M14 there is simply no comparison. The views in the M14 are just stunning and the detail blows the 5" APO out of the water as it should. However, I don't drag it all over creation either - this is why we have the APOs. ;) And this is why I am adding the 10" to my arsenal of optics. Easier to carry around.

And again, seeing makes all the difference. I am 100% convinced that if my M14 was back in Michigan it would be hardly used - and the APO would be used almost all the time.

#16 pogobbler

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Posted 09 July 2014 - 01:06 AM

I'd go with those who say the step up to an 8" SCT would likely not be large enough to be worthwhile, though they are such nice, compact and lightweight scopes. I think a 10-11" scope would be the first really noticeable step up, aperture-wise. Definitely more bulk and needs a decent mount, but the 5" fills the more portable, easier to set up niche just fine.

#17 moonnerd

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Posted 09 July 2014 - 09:20 AM

Thanks guys. This helps me realize even more that a good 5" refractor is a really good idea.

Lets say I had a G11 mount to handle a C11 or Meade 10" ACF, and had a platform for a dob. And lets say it was stored in a shed outdoors, and where the temperature drop offs are not extreme... If we were going on optics alone, and we're looking for small stuff on the moon (think Alpine Rille or craterlets) and more details on planets... do you guys like a C11 or 10-12" newt?

#18 t.r.

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Posted 09 July 2014 - 12:08 PM

So, as the others have said, skip over the 8" and 9.25" SCT. For a complimentary "wow" factor, the C11, M12 or larger should be considered. The reason most recommend an SCT is because you are in a CAT forum and also that you said, backyard observer, implying setup. If you already have a 5" triplet and mount it on a GEM, you are home free for taking advantage of the smaller size of an SCT for portability and using the same mount. I have purposefully stayed away from dobs because of portability, collimation and ease of use issues, so the SCT really has its place. It's stellar images do suffer a bit, but their "star blob" reputation is over exaggerated. Don't over magnify and things are decent enough for the casual observer.

I have the very combination you ask about, an AP 130F/6.3 and a C11XLT which I use one at a time on a Goto GEM mount. They compliment each other perfectly. What one lacks in, the other makes up for. Both OTA's are portable enough to make backyard use easy and uneventful. I have even viewed through the 5", found the seeing exquisite, taken it off the GEM and put on the C11 to take advantage of the extra resolution for planetary details in the same session. When the seeing is average, the 5" refractor is the primary instrument when viewing planets/Lunar/doubles. When the seeing is better or DSO's are the main target, the C11 is used. These two instruments are the last size jump before a much larger mount and extra setup requirements become necessary. A 6" refractor and a C14/M14 are in another league and require a dedication and commitment from the user. The 5" & C11 combination are in the "Goldilocks" zone for most, with price, performance and portability in perfect balance. A G-11 should handle both nicely...good luck! ;)

#19 edl

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Posted 09 July 2014 - 12:09 PM

I find my Edge 11 a perfect compliment to my 5" refractor. My main mount is a SW AZ-EQ6.

Best,
Ed L.

#20 Jon_Doh

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Posted 09 July 2014 - 02:55 PM

Orion makes goto dobs up to 14" in aperture.

#21 Patrick

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Posted 09 July 2014 - 03:16 PM

do you guys like a C11 or 10-12" newt?



Newts are slightly better on optical performance, but the tradeoff is the size and nudge factor. For high power viewing, the nudge is a turn off.

Also, I don't know if you've ever used an EQ platform, but I've owned two and can tell you neither one has made things much easier. Yes, they track, BUT, they also introduce a serious amount of extra sway to the mount system as a whole. Instead of things settling down quickly, the platform adds multiple seconds to the settling time. Couple that with the need to reset the platform every hour or so and they can become a PITA.

Just an FYI.

Patrick

#22 BillP

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Posted 09 July 2014 - 04:09 PM

Would a C8 be enough of a jump up or would it need to be at least a 9.25?


I have a 6" APO and I do not feel my Meade 8" SCT is a worhtwhile difference at all. I'd say you should be looking at a 10"-11". You could get a used XT10 and then retrofit with a Zambuto mirror ($1600).

#23 jgraham

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Posted 09 July 2014 - 04:43 PM

My eperience has been that the larger size of a Newtonian gives it a higher moment of inertia and tends to take longer to dampen vibrations. Given scopes of similar sizes I'd go with an SCT as they pack a lot of focal length into a small package. Where I would consider a Newtonian is if I were looking at a much larger scope. My absolute favorite lunar and planetary scopes are my deforked 10" LX6 and LX200. These scopes are very comfortable to use and the views are usually seeing limited. When the seeing supports it I move up to either my 16" f/4.5 or 16.5" f/6.5 Newtonians.

#24 BKBrown

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Posted 09 July 2014 - 09:20 PM

I also do lots of lunar and planetary work, visual and imaging. I find my C11 Edge and TEC 140 (5.5") to be an ideal combination. The C11 provides the extra kick and cools down reasonably fast with the TEMP-est fans installed. The TEC is just a beautiful Apo refractor all around and will always perform well, even on those nights when I can't get the best out of the C11. Together they make a great team...

Clear Skies,
Brian

#25 Starman27

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Posted 09 July 2014 - 10:18 PM

A Meade 14 LX200GPS is the companion for my TAK FS 128NSV. They are a good match. Both are pier mounted next to each other in the observatory.






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