Planetary scopes

I honestly hope that this doesn't start some sort of holy war, or any form of spat. I've been thinking about this for a year, though, and finally thought it worthy of tossing out here.

Todd Gross reviewed 70+ scopes, including many really high end refractors. Yet, when he chose to pick what he considered "The Best Planetary Scopes", nothing under 6" even made the first 9 picks, and mid-sized DOBs got the first several slots. Here's his list, directly from his famous site:

"BEST PLANETARY SCOPES SO FAR..

1. 14.5"
2. 16" & 18" Starmaster w. Zambuto and Pegasus optics 2. 12.5" Portaball from Mag1
3. 10" Teleport w. Zambuto optics
4. 8" Portaball with Zambuto optics
5. Takahashi FS-152mm & Currently Testing FCT150mm
5b. 6.1" D155 f/7 Astrophysics EDF
(Two above are close, TAK seemed better, Ed Ting is testing them against ea. other, and has come up
with the opposite conclusion)
(Takahashi TSC225 seems to fall approx. here.. as for the CN212, planets were not available)
6. C-14 SCT (not 100% positive, needed better seeing to confirm, brief test only, use this with skepticism)
7. C9.25" SCT Celestron SCT
8. 7" Starmaster with Zambuto optics, and 7" Teleport with Zambuto optics
9. Ultima 2000 8" SCT
10. 5" Takahashi refractor FS128 & 5.1" Astrophysics EDF (planets not avail. when FC125 was used)
11. Intes MN56 Mak-Newt (5" f/6)"
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Granted, I know that's just one guy's opinion, but he's certainly one of the most experienced folks out there. But when I look at that list, I really wonder why some folks are so eager to part with mega-bucks for 3-4" refractors. (I'm not knocking them, at all. I just really don't understand.)

It's also very, very interesting to me that the only scope on the whole list that I have any real experience with is the lowly Intes MN56 5" Mak-Newt. That scope seems to me like the real sleeper planetary scope. The fact that it even made such a distinguished list fascinates me. It may be last on the list, but it's commonly available for not much $$$, and it beat out many high end scopes just to make that list. I actually would've thought that several of the 4-5" APOs would easily beat it on planets.

What's anybody else make of all that?
Mike Swaim

Jay Reynolds Freeman says, "Aperature wins."

As an owner of a 12.5" f5 Portaball with a Zambuto mirror, I'd ammend that slightly and say, "High quality aperature wins."

But when the flame wars come (and they surely will), I promise not to say anything more.

Hey there,

I am one of the people considering the 4" APO for planetary. The reason I am considering this is becase of several reasons. I have never owned a refractor and if I get one I want it to be a smaller APO versus a bigger Achro. I do not dissagree that his list is very accurate however the first 4 scopes do not track (without an EQ Table anyhow) and that is something I cant live without. The next 2 on the list, 5 and 5b, are not even remotley feasable. As for the SCT's, I have done the C11 thing. It was definatly no slouch and I may very well end up with another soon.

Hope I didnt rable or ruffle feathers. That is just my reasoning. Oh, I am also seriously looking at the 6.5" OA scopes as recomended by a member in my revious post.

May the sand be settled for your viewing.
Mark

A 4" apo does indeed put up some fine planetary views, but (IMHO) no matter how good the 4" optics are pushing it much over 200X you will notice image degradation on the planets. If you live in an area where the seeing rarely permits much over 200X, and, or you really have a limited amount of time to observe, a 4" apo would be a good choice, (easy to drag out on the porch and very short cool down time) You really have to decide whats right for you and your circumstances. Ron Bee who posts on these forums has done some nice objective planetary comparisons between a 4" apo and 8" dob. However, all said and done, on nights of rock solid seeing I feel that its hard to beat a large newt with exquisite optics. I'm no expert but I have had the opportunity to observe through quite a variety of scopes, 12.5 Zambuto, 16" Pegasus, TV and Tak 4" apo's, a 5.5" TEC apo, and a 7" AP, and on nights of good seeing, the quality big reflectors showed more detail on the planets. That said, I do enjoy the planetary views through my 4" Tak and I'm sure I will be happy with it for a long time to come. I know its not much help, but this has been my experience viewing planets.

I feel that it is very difficult to make a list of anything and state which is best. Even the manufacturer can not guarantee the one you get will be as good or better than the one tested. For each answer there come three questions.
1) Was this an equal test. You know conditions vary by the minute.
2) Were all other things equal? Same EP, collimation correct, was the test scope a retail offered scope?
3)Did everyone that looked through them agree? Unfortunatedly that is something that I doubt a lot. No one agrees a=on anything when it comes to what gives the best view!
I think that there are great scopes out there and poor ones made by the same people. Mass produced scopes are never carbon copies of each other. Some manufacturers actually will put out a (Sleeper) scope for testing with hand picked optics.
For instance, I know someone that has an in with a big factory. His friend runs the quality control section. He got a 12" SCT from them and it sucked badly. He sold it and they are putting together another one for him that has hand picked optics.
When they test the mirrors they use the best for the most expensive models,(Figures huh?) and the worst mirrors for the cheapest models. They rate them 1-5 is what I am told. Even so, some of the best don't work well when they are put in a scope. So the scopes are all different.
My $.02 woth, thanks for listening.
Floyd

Mike,

I've owned 10" Meade SCT, 12.5 PDHQ Discovery DOB, 8" SCT C8 and a couple of 6"-8" Newtonians. None of these scopes even came close to the sharpness and contrast of my 5" APO. If your primarily interested in these 2 benefits for observing planets, my opinion would be to go with the an APO. However, if you prefer brighter and more detail resolution on planets, then I would suggest a larger aperture reflector. I've looked through a recent C9.25 and it provided me the best images that I've seen through an SCT to date under 11 inches. However, the Newtonians me showed slighter sharper planetary images than the 10" and 8" SCTs.

Rob

I like the telescope Lara Croft used in Tomb Raider as she watched the planets approach alignment. It looked like maybe a 12' SCT. That would work well I think. Unfortunately I can't tell you what is really best. The best I used was a Meade 10" LX50. Not too portable so now I use a 5.5" refractor or 8" Newt and the Newt is better, bigger anyway. Personally I'd take the setup Lara had but I'm twenty million dollars short on funds.

But, that would work at least as well for all but a few other scopes else on the list ..... so if you count wheels in the "portable" category, why spend what is truly megabucks on a 6" APO if something bigger in aperure yet smaller in weight and a lot less expensive moves just as well on wheels?

The admittedly valid "ease of use" argument only works for up to 4" APOs.

Location can make a difference in the decision on a planetary scope. Up here in the northern US, my choice would be an APO in the 6 to 8 inch range, or a quality 8 to 10 inch Newtonian of moderate focal length.

In addition to having better seeing in parts of the southern US, both because of local conditions and because the planets are higher, temperature drops at night are not as big an issue (for the most part, anyway). Up here, where temperatures are often dropping much of the night, the mass and heat content of a large Newtonian primary means it is almost always playing catch up. Closed compound systems are also generally trying to play catch up and do not reach their potential.

Clear skies, Alan

A perfect subject for controversy! My main point is that atmospheric conditions are overwhelmingly important. I've been using my 6" Mak-Newt and 14" Discovery Newtonian (both excellent scopes) side-by-side for viewing Mars. On nights of average seeing the 6" usually provides sharper views. When the seeing is unusually good the 14" beats the pants off the 6". I wouldn't want to use anything smaller than 6 inches because you can't get enough magnification to see all the detail permitted by the atmosphere. If you go beyond 25-30x per inch the image starts to look "grainy" due to eye defects, ruining the ability to see faint contrast. I know some people claim that a 4" refractor is perfectly matched to the atmosphere; I've never owned one so maybe they are right or maybe I just have bad eyes.