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C14,versus a 10" apo... What will you do?

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#26 jrbarnett

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Posted 21 March 2013 - 10:27 PM

Now that you mention it, a hundred or so people a year who opt for a lowly 5.5" TEC 140 over a C14 OTA, the latter being cheaper than the 5.5" TEC, make a similar choice to the one you describe. :grin:

- Jim

#27 johnnyha

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Posted 21 March 2013 - 11:02 PM

I know this is the Cat forum but it is surprising to me as well as noted before, many would opt for the 30% obstructed commercial mirror over a handmade work of art with no obstruction, no diffraction, perfect images. Of course the mounting issue is not at all practiclal in fact almost... insur-mountable. :whistle:

:tonofbricks: :step:

#28 Mark Costello

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Posted 22 March 2013 - 08:26 AM

I know this is the Cat forum but it is surprising to me as well as noted before, many would opt for the 30% obstructed commercial mirror over a handmade work of art with no obstruction, no diffraction, perfect images. Of course the mounting issue is not at all practiclal in fact almost... insur-mountable. :whistle:

:tonofbricks: :step:


One reason might be because that the cat would be a good bit more maneagable than the large refractor. Personally, I'd take a 8" SCT or Dob over an 8" refractor, no matter how good it was - any day, hands down, not look back....

#29 mikertx

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Posted 22 March 2013 - 11:47 AM

I think you bring up an interesting point. You can view a telescope as a cherished work of art or as a tool for accomplishing a task. Both views are completely valid. I can't bring myself to sell my TEC140 even though I don't use it much because IMO it's a work of art. For most of what I am doing these days (spectroscopy, photometry) my C11 is a much better choice.

Mike

I know this is the Cat forum but it is surprising to me as well as noted before, many would opt for the 30% obstructed commercial mirror over a handmade work of art with no obstruction, no diffraction, perfect images. Of course the mounting issue is not at all practiclal in fact almost... insur-mountable. :whistle:

:tonofbricks: :step:



#30 cavefrog

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Posted 22 March 2013 - 08:37 PM

First, you're comparing an off-the-shelf SC to a hand built refractor. This is a common comparison, one I could never understand.

Now, let's get Mike Lockwood to make us a hand figured primary and secondary mirror to the very best of his ability...maybe Mike's best mirrors ever! And we'll also get Mike to figure the corrector as closely matched to these mirrors as his prolific skills will allow.

Now, let's make sure that the OTA has active cooling. And let's make sure that the tolerances of the mirror riding on the baffle tube is incredibly tight, to the point that the lube is specially formulated so that it can be very slippery but the amount of lube is only a few microns. And the focusing mechanism is extremely rigid to limit image shift to virtually nothing.

Ok...now we would have a fair comparison in optics, mechanics and price. :grin:

David


+1... NOW your talking comparison!!! :jump:

Theo

#31 azure1961p

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Posted 22 March 2013 - 09:58 PM

First, you're comparing an off-the-shelf SC to a hand built refractor. This is a common comparison, one I could never understand.


Hi David,

The comparison to a stock C14 was intentional as an optimized one to your spec (which Is a nice spec) doesn't really speak for the instrument on its own out of the - real world - box (as most people would use it). It is that the instrument is nt a custom product and is readily available at a fantastic price that makes it the contender it is. I didn't see the c14 as a mass market whipping post but rather the possibility in this hypothetical that off the shelf it is better for a variety of objects. It'd be gangbusters to be sure with all those custom fabricated optics but the achievement here is in the success of the instrument with out it.

Pete

#32 Darren Drake

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Posted 22 March 2013 - 10:35 PM

Lets not forget what Damean Peach uses to image the moon and planets....

#33 Fomalhaut

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Posted 23 March 2013 - 05:54 AM

I'd take a 7" apo over a C14, does that count? Never been a fan of those short, stubby looking things aside from small Maks. Although, to be fair I've never seen the views through an Edge HD.


I had owned and frequently used two different C8s (an orange good one, and later on a "so,so" black Powerstar one) for over 20 years.
Meanwhile, for the last twenty years, I've had (amongst other scopes) two good 4-inch apos (at first the Vixen Fl-102 and after that a perfect Tak FCT-100). Instead of a C8 I now have a Mewlon-180 delivering at least the same performance as the better of my past C8s, and I'm using it on fainter galaxies, GCs and PNs.
So I believe to have "the best of both worlds" within my weight-class (terrace, no permanent mount plus problems with my disks).

If I had to decide for just one scope, the one which would stay would be the 4-inch apo. - It may show less than the 7-inch-DK on the objects mentioned above, but what it shows is (comparatively independent from seeing conditions) of outstanding contrast and beauty! Through the SCs or MCs or Casses I have always felt like looking at kind of nice pictures, while the Apo seems to show me "the real thing". This may sound magic, but nevertheless in my case is the case :smirk:...
Thus, my decades of observing with apochromatic refractors (AND reflectors) somehow must have spoilt me irreversibly :shrug:.
OTOH, I'm still happy to own both!

Conclusion: When now thinking of scaling up both of the above scopes by the same factor of 2 there results exactly a proportional pair of a hypothetical 14-inch DK/SC versus an 8-inch Fluorite triplet refractor... :question: => Personally, I'd prefer that one.

Chris

#34 ValeryD

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Posted 25 March 2013 - 03:48 AM

A couple of weeks ago, Roland Christen posted an interesting discussion on the largest practical size for APO refractors using current design technology. In particular, he said that for a 10" APO triplet, it was impossible to get visual colors to come to the same focus, while also correcting for spherical aberration. This discussion was in the context of why a 10" Mak-Cass was putting up better views side-by-side than a 10" APO at a particular star party.


Can you, please, give a direct link to this discussion where Roland said such things?


Thanks.

Valery.

#35 De Lorme

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Posted 25 March 2013 - 04:02 AM

Apo for sure. Find some way to mount it. De Lorme

#36 Illinois

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Posted 25 March 2013 - 06:16 AM

I remember that Astronomic selling 254mm (10") F9 OTA for $39,999....just tube!!!!! If I can afford it and I wouldnt buy it. Meade 16" SCT!

#37 Classic8

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Posted 25 March 2013 - 09:49 AM

I remember that Astronomic selling 254mm (10") F9 OTA for $39,999....just tube!!!!! If I can afford it and I wouldnt buy it. Meade 16" SCT!


That would look impressive set up in the living room. :D

#38 WadeH237

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Posted 25 March 2013 - 12:58 PM

Can you, please, give a direct link to this discussion where Roland said such things?


Thanks.

Valery.


It was in a conversation on the AP-UG forum. Here is the direct link to his quote (which I paraphrased).

-Wade

#39 AlienRatDog

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Posted 25 March 2013 - 01:15 PM

If I bought a 10" APO, I would need to take out a loan for my divorce attorney. My APO and I would most likely have to get an apartment somewhere - but at least we'd be together. :grin:


FYI there are A LOT more women than 10" APOs out there...just sayin'...

#40 Paul G

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Posted 25 March 2013 - 05:41 PM

If I bought a 10" APO, I would need to take out a loan for my divorce attorney. My APO and I would most likely have to get an apartment somewhere - but at least we'd be together. :grin:


FYI there are A LOT more women than 10" APOs out there...just sayin'...


:lol:

Go Blue, beat Kansas!

#41 clintwhitman

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Posted 26 March 2013 - 12:43 AM

That's why Roland made the Pearl a 9" APO at F 10.6.
:bow: :bow:

I have to live with this set up in our permanent observatory. While I have been known to be very happy when using friends TAK Mewlon 300 There are not any telescopes I have found that out perform it. My friends 10" F15 Zeiss will but it has not been setup in years now. Personally I guess you have no idea what a 9" AP can do until the seeing lets the scope cut loose and hold Mars or Saturn at 700 power for an hour or two. After this happens a few times, coupled with the resolution that the triplet produces a truck load of C-14s and a gun could not get this scope out of my observatory... :foreheadslap:
(aveman

Clint and Philo With the Pearl At CSPAMP VI Mnt Pinos

#42 rflinn68

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Posted 26 March 2013 - 11:46 AM

This is really silly. Have you looked at the price of a 10" apo??!!! Take the apo and sell it and buy ten C14's if you want to! I really do love apo's, sct's, and newts, but for equal amount of money spent on each type you cant beat the view you'll get with the newtonian.

So me, I'd take the apo and sell it. Then I would buy a 6" apo, C14 EdgeHD, C8 EdgeHD, 12.5" Teeter/Zambuto Planet Killer, AND a Teeter/Lightholder 20" f/3.5 decked out with a motor drive. You'd still have money left over for a very nice mount for the refractor and SCT's. $50,000 can still buy a lot :grin:

#43 Ed Holland

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Posted 26 March 2013 - 02:47 PM

Probably a waste of time for me to take either option... I want ease & rapidity of setup as a priority, then ease of storage. I'd take the C14, and donate it to the local school.

#44 Eddgie

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Posted 27 March 2013 - 11:36 AM

Why didn't you include something like a Go-To 12" f/5 dob with Zambuto mirrors?

That would be my choice over these other two.

In fact, it is my choice. I have been wanting one for two years now.

Reflectors rule. :roflmao:

#45 JJK

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Posted 28 March 2013 - 12:26 AM

10" apo.

#46 rathbaster

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Posted 28 March 2013 - 06:51 AM

I'd go with the C-14

Since it's "free" I would have it custom painted white with a blue back and highlights. That way when its sitting in storage it looks like R2-D2.

#47 cavefrog

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Posted 28 March 2013 - 03:44 PM

You just gave me an excellent idea for a storage dust cover!

Thanks,
Theo

#48 DaemonGPF

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Posted 28 March 2013 - 09:09 PM

If I'm not picking up the tab, the 10" Apo...the APM/LZOS 254mm f/9 is my "dream" scope". But at 42,773 euros ($55,177 US) it is unattainable by mere mortals. Not only the cost of the scope, but you'll spend a hefty percentage of that price getting a first rate mount and accessories; and of course it cries out for an observatory. So even if you got the scope free, you'll be dropping 50k for other stuff. At least I could use my TEC 140 as a wide field finder :grin:

Clear Skies,
Brian



Pfft... CLEARLY a grab-n-go type of instrument for small, wild star parties with lots of little kids running around loaded up on sugar.
:lol:


Seriously though, I was pondering this as I started to read the thread. Then I tried to visualize a 10" APO. Now that I've seen this pic the first thing that popped in my mind was "Holy ____, that is rediculous!" I would just love one peep through that sucker, but I'd have the fear of god in me owning one.
:cool:

#49 Fomalhaut

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Posted 29 March 2013 - 02:46 AM

What I will do?

Based on cost-efficiency-ratio, and if I were not a rich institution, I would certainly never buy an apo > 6 inches. And without permanent mount plus housing, not even an apo > 5 inches.

Question from my side: Are modern C14s ventilated nowadays? And has QC been substantially improved compared to yesterday?
=> If not, I wouldn't either ever buy a C14, be it EDG or SCF (strongly curved field), thank you.

Chris

#50 nytecam

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Posted 29 March 2013 - 04:49 AM

I would get the 10" APO and sell it. Then I would invest the money on a remote observatory and all the equipment needed for that.

Hopefully the gifts would contain the proviso of being used not sold for profit :o






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