Research:Planet Killer Scope Fight Out!!

[Rob]

So with lots of discussion round this area right now. I thought it would be to start a thread throwing in some scopes as a comparison. So here we go.

Now I looking to find the best scope to provide the over all resolution/detail pull out. Contrast. Brightness. Image Scale. Primarily for visual, but info on imaging for the imagers would be useful.

1. 200mm f5 Newt

2. 120mm Evostar Achro Refractor

3. 100mm ED Refractor

4. 100mm Tal Achro

5. 80mm ED Refractor

6. 127mm Mak

7. 150mm Mak

I wanted to put a poll in here to assist.. but the options did not allow me to go comprehensive enough. Lets try and nail some good info for those looking towards the next session.

Rob

[Whippy]

Interesting Rob! IMO,I still think an 8" newt is a great all-rounder so for a bit of everything, including imaging it'd be the newt but if we're talking purely solar system imaging then I think the 6" Mak-Cass would be my choice down to it's longer focal length.

If we're looking at a portable setup then it'd either be the ED100 or more likely the 5" Mak.

Tony..

[dweller25]

Good thread - and a topic close to my heart as I am a purely visual planetary observer.

Perfect collimation, good contrast and fast cool down are essential for the planets so IMO refactors are the best - a 5" ED is the minimum I would use as it can be used at x250 which Mars requires. The equinox 120ED whilst not on your list would be a very good choice.

Newtonians are my next best choice (but only because I find then uncomfortable to use) - the Skywatcher 200 F/6 is excellent as it has a smallish (23%) secondary. I added flocking and a cooling fan to mine and it's performance was excellent.

I have tried Maks and SCT's but collimation and cooldown were issues that I did not need.

If I had to pick one scope from your list it would be the 200mm F/5 Newtonian.

But the scope I use most on the planets is my Tak FS-128 with binoviewers.

HTH

[ollypenrice]

The biggest apo you can afford. I find that sometimes the 10 inch SCT beats the TEC140 apo but 80% of the time the TEC beats all comers.

The 20 inch Dob can sometimes surprize, notably on Jupiter for some reason, and I don't have a slow f ratio Newt which might well be the business. The big Dob at F4.1 is clearly not planetary in aspiration!

But, for consistency, a big apo. Fast cooldown, no collimation, little dew, low dependence on good seeing. I bet the ED120 is great as is the Meade 127. The Altair 115 is also prety crisp. No, very crisp.

The big Mak would be great were it not for cooldown.

Olly

[Graham Darke]

I have to agree with Olly. On the very best nights of steady seeing a large reflector whether Newt or Cassegrain will provide the best views. However on all other nights my TEC 140 wins hands down for visual. Considering the limited number of those special nights we get each year I prefer my TEC's views to anything else. I am primarily a visual observer. When it comes to imaging however aperture is always going to come out top so the bigger the better and the Cassegrain scopes with their longer focal ratios come into their own - hence the proliferation of fine planetary images from SCTs.

[John]

I notice that the maksutov-newtonian design is not on the list - perhaps because it's not a common design ?.

I've found my Intes MN61 an excellent planetary scope, even surpassing (very slightly) my previous 6" refractor / Chromacor combination plus it's much more managable than the latter.

I'll be taking delivery of an Skywatcher ED120 Pro refractor shortly so it will be very interesting to see how that stacks up against the mak-newt for planetary use.

On good nights I've had great planetary views with well collimated SCT's and newtonians as well so it's not a straightforward issue to settle but, on the whole, I tend to feel that a medium-large apochromat is likely to deliver the most consistent and hassle-free planetary performance.

[russ]

Visually for me it has to be one of the bigger Intes Micro Mak Newts. I doubt there is an Apo that will surpass them. The MN78 was a true planet killer. Best planetary view i've had through a scope was with an MN86.

But for value for money the 150PL does a mighty fine job as a visual planetary scope. And the 200P F6 dob OTA is extremely good too.

For imaging is it fair to say the SCT is undisputed champion of the world? All the worlds best planetary imagers use one in some form but mainly the C11 or C14.

[iwatkins]

180 Mak works well once you've cooled it (and that isn't as bad as people make out). Small package makes it easy to handle too.

But would have thought a big refractor would also suit well, say a 150mm/6" achro.

As someone about to return fully to visual usage, I've found imaging isn't for me, this is a subject close to my heart.

Cheers

Ian

[Rob]

Thanks for you input so far.. I know Mak Newts are held in hi regard. I think though the general budgets would cover the initial list. that said theres always a place for those wishing to purchase in the upper bracket.

I know there are a lot of people now looking to purchase a second scope, and it always seems to be a 50/50 split. Planet scope or widefield.

[DaveS]

Just to come in here (From my "where to now" thread), if a 180 Mak-Cass were kept under a Telegizmos 365 cover would that ameleorate the cool-down time?

Or aren't they as good as advertised (I know nothing is, but you know what I mean)

Dave

[beamish]

TBH it's not "cool-down" time more precisely thermal equilbrium with the environs, so could just as well be "warm-up time", but to the question- the simple answer is YES

[SiriusB]

Hi Rob,

From those you've listed i'd go with the 200mm newt, which i see you already own.

The question is, what seeing conditions prevail at your locale?

For me, a 200mm would be wasted because planetary seeing is generally absolute pants for me, 120mm or less would be about it most of the time.

[Rob]

Hi Rob,

From those you've listed i'd go with the 200mm newt, which i see you already own.

The question is, what seeing conditions prevail at your locale?

For me, a 200mm would be wasted because planetary seeing is generally absolute pants for me, 120mm or less would be about it most of the time.

In Short.. my 200P DS is so good on the planets it staggers me. I'm very lucky to live next to the water. My east & south are dark, really dark.

[Rob]

I thought it would be a good discussion point ahead of the session....

[asteria]

My preference - MakCass, 150mm. A great scope that delivers super views of the planets. I have had some awesome views of Saturn, and I can't wait for Jupiter.

I have also had some incredible views of the Moon, not planetary I know, but I'll swear that the view was just like flying over the lunar surface. I was very impressed.

The cool down is not too bad, and it is a very portable scope - compact tube with great optics.

I'm probably biased, because I've got one! but it's also very enjoyable to use. I've never found collimation to be a problem, but I do handle it very carefully, although to be honest the whole tube feels like it's made of cast iron!

Ed

[Whippy]

Visually for me it has to be one of the bigger Intes Micro Mak Newts. I doubt there is an Apo that will surpass them. The MN78 was a true planet killer. Best planetary view i've had through a scope was with an MN86.

But for value for money the 150PL does a mighty fine job as a visual planetary scope. And the 200P F6 dob OTA is extremely good too.

For imaging is it fair to say the SCT is undisputed champion of the world? All the worlds best planetary imagers use one in some form but mainly the C11 or C14.

As it happens Russ, I managed one night to compare my ED120 with the Argonaut on the Moon and Jupiter and I was left with the impression that it's close, very close but the aperture wins, just although the view was nicer through the 120, I assume that was down to the slightly better contrast. Both were very good though!

I still like the idea of an 8" f8 newt though, good aperture and given that the secondary would be quite small, contrast wouldn't be an issue either, nor coma. From what I've read, the f8 MN's don't have the same advantage as the f6's as coma isn't that big an issue with longer 'normal' newts.

IMO, SCT's are only the solar system imagers' weapon of choice because there isn't any other real option. Mak-Casses larger than 8" seem expensive and bulky in comparison, same as large newts.

Tony..

[A McEwan]

Some of the best planetary views I've had have been through my Equinox 120ED, 180mm Maksutov and 8" f6 Dob. Ok, none of those are on your list, so I'd go with the 150mm Mak in this case - not that I've looked through one - but I imagine as a "scaled ddown" 180 it would perform excellently.

Ant

[Rob]

Please feel free to add your scopes to the list.. This an information thread on finding the desired view, through the weapon of choice (if you like).

Cheers All for your comments thus far

Rob

[Stu]

200mm Mak? :-)

Stu

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[Rob]

200mm Mak? :-)

Stu

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You can go right off someone....

Nice mate.. very nice indeed. That will offer super views I'm sure.

Rob

[Ags]

Well, I'm about to gamble on a 150mm Mak... ;-)

[A McEwan]

Not much of a gamble, to be honest, Ags!

[Stu]

Hi Rob

If it makes you feel better, it's a fickle beast, very sensitive to seeing conditions. To quote a phrase, 'When it's good it's very very good, when it's bad it's awful' !

I've had the most stunning views of Saturn through it, looking forward to having a good crack at Jupiter from a dark site later in the year.

Stu

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[Moonshane]

the best planetary scope I have looked through is my own 6" f11 newt.

I'd really like to compare it directly with some other scopes but have not had chance to do so. as others have said, the 12" f5.3 I had also provided jaw dropping views of planets occasionally.

I will be very interested in John's comments on the 120mm ED vs the Mak Newt.

[AndyH]

If I was going to get a planetary specialist scope, I reckon I'd go down the Russian M-N route. Bare in mind I'm a visual only bloke though.

Andy.