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Deep sky - SCT or APO?

Started by mricklin, 03/18/2003 09:48PM
Posted 03/18/2003 09:48PM Opening Post
Hello all,
I am shopping and need help on my decision of SCT or APO. All the postings and reviews rave about APO contrast, portability, planetary observing, etc. And some seem to indicate that less than perfect seeing conditions or light pollution favor APOs. Well, in the high desert of New Mexico where I live, where many nights are crisp and dark, will an SCT do as well? What is best for galaxies? Can the 4" APO be used or is that good only on planets and nebulae? I want to spend about 3500 which could buy a Meade LX200 12" with UHTC, or a TAK 4" on a GP-DX.
Thanks,
Mike
Posted 03/18/2003 09:56PM #1
$3500 gives you a lot of choices. APO's are supposed to give you nicer views. The SCT 12" will let you see more and further, it has about 9 times the light gathering power, and greater resolving power. Then there are all the other possibilities, a high quality dobsonian truss (say 14-15 "will give you better, brighter, views and is probably about as portable as the Meade and its massive tripod, should cost half as much, and be more reliable. A Maksutov either Cassigrainian or Newtonian will give you sharper views than the SCT, although you won't get to 12 inches set up at that price.
Posted 03/19/2003 12:00AM #2
Oh good, another APO vs. SCT discussion smile

Here's my take:

For the same money, APOs can't hold water to an SCT (or any reflecting scope, really) for visual deepsky, period. You get almost 10x the light per $$. IMHO, aperture always rules. They way you're asking the question and if you're into deeksky, the last thing you want is an APO if that's your only scope unless money is absolutely no object.

IMHO, again considering the price of a really good APO, it may be justified only if you do exclusively planetary work, and even then many argue that the same money will buy an SCT/dob/Mak that will perform equally well or better in most cases. I yet have to see the APO that will outdo a 10-12" SCT/dob/mak even for planetary work, except maybe some 6-incher way into the 5-digit $$ range. Less than perfect seeing - sometimes I suppose if the conditions are just right, and darker background - sure, at a lot less light the background will be darker . So will the image. (OK, they do have slightly better contrast)

Refractors (at least short focal length ones) are also great for wide field viewing, but at 20x mag it doesn't necessarily have to be an APO and/or a dob can do the same job for less money.

But then again, these discussion we had plenty on this board already. It's nearly a religious issue for some.
Posted 03/19/2003 12:00AM #3
Definitely SCT. Scopes with larger aperture and longer focal length rule (unless you're into astrophotography). You may want to consider a good quality 7 or 8" mak-cass.
Posted 03/19/2003 12:01AM #4
I just purchased a "2nd" Orion/Vixen 140 NA Refractor, Vixen 7x50 finder, tube rings, a Williams Optics 2" diagonal and a year old Losmandy GM8 for around $3,500. I have not used it because it hasn't arrived. I sold a TV Genesis recently and I've owned a 10" Meade Lx50. I do like the views of star clusters and binary stars more through the Genesis but the SCT provided for better views of galaxies and planets. I didn't care for the bulk of the LX50. I'm hoping this will be the happy medium, though the NA is not an apo. I know it will handle 400x so planets, deep space should be good. My 2 cents, although it's only worth about 1 cent.
Posted 03/19/2003 12:33AM #5
Mike,

For $3500 in New Mexico, I would go for a Starmaster ELT 11" or 12.5. They are very portable as Dobs go, give you much wider views than a SCT or APO, and the Zambuto optics will give you killer lunar/planetary images that will knock your socks off in addition to the awesome DSO views. The downside if if you want to image/photograph. But then again, to get a comprable APO in the 5-6" range, you would spend more and still have to purchase a mount.
As far as a SCT is concerned, I would rather have a Mewlon 210 or 250 or perhaps a TEC but, again you still have to spring for a mount as well.

Just my $.02
Owen
Posted 03/19/2003 12:39PM #6
You need two scopes. Trust me.

Erlend
Posted 03/20/2003 05:22AM #7
A high quality Newtonian Dob is a better choice.

Dave Mitsky

Chance favors the prepared mind.

De gustibus non est disputandum.