Which scope for planetary f10 / f12 / f15

[Chris]

I agree with others that you already have a better planetary Lunar scope with the Mak127 than any of the 80mm fracs you're looking at, purely by the aperture and focal length which will give you resolution and image scale (Although the StellaMira 80 f10 would probably give pristine views for the small aperture it has)

 A step up from your Mak127 would be something like a C8 SCT or an 8" Classical Cassegrain, although there is one other wild card scope that will beat the Mak127 for planets and it's actually really affordable one - The Skywatcher 150pl OTA, or the Skyliner/Classical 150p Dobsonian if you want it on a Dob mount. 

It might not sound much of a jump, but the effective aperture of the Mak127 is 120mm, so it would be 120mm verses 150mm. 

Just depends on budget of course, go with 8" if you can, but if not you have an option still : )

[nfotis]

I don't see any mount mentioned in the discussion, shouldn't we know that parameter as well?

IMHO, the upper class of reflector mass production scopes for planetary imaging and observation are (the ones easily handled by a single person):

C9.25 XLT and edge HD

Classical Cassegrain 8"

Skymax 180

And their little brethren:

C8 XLT and edge HD

CC6

Skymax 150

Since the OP has already the Skymax 127, I suspect that the 150 won't be a large step up to be noticeable?

N.F.

Edited March 31, 2021 by nfotis

[AlexK]

You don't need a long focal for "planetary". You CAN use long focals for "planetary". However, to have mind blowing planetary views, you actually want the greatest aperture you could afford (to get and handle) instead. The minimal "planetary" aperture (for truly interesting views) is 150mm. But only with the 300mm aperture at hand I've started to see space craft flyby kind of planetary views when our own planet permits...

I see mounts mentioned as well? Just on a side note: with the experience, you can manually guide with pleasure for hours at 500x on a decent 100% classic scheme Dobsonian mount. Just with your single finger touch in the right spot. At 800x it's getting a bit challenging, but having a 100 deg AFOV EP helps to amend that.

Edited March 31, 2021 by AlexK

[John]

9 hours ago, AlexK said:

....The minimal "planetary" aperture (for truly interesting views) is 150mm.....

 

Now there's a line that would create a lively thread in it's own right

 

[Stu]

10 hours ago, AlexK said:

The minimal "planetary" aperture (for truly interesting views) is 150mm. But only with the 300mm aperture at hand I've started to see space craft flyby kind of planetary views when our own planet permits...

I don’t happen to agree with this, a 100mm apo can give perfectly satisfying planetary views under a range of conditions.

Of course you are correct about larger apertures giving better resolution, but so much depends upon seeing conditions. We are on the wrong side of a rather large puddle, on the receiving end of a variety of weathers and not infrequently sit underneath the Jetstream. Those things considered, it is often the case that smaller apertures compete surprisingly well with larger. When seeing is excellent though, aperture wins.

[Stu1smartcookie]

The best , sharpest , most colourful , largest planetary views are ..... from the likes of the Hubble , translated into photos that are in most Astronomy mags . So , thats it ...end of . I will expect to see a whole host of astronomy equipment posted on here in the FOR SALE section . 

But .... hang on .... we knew that , didnt we ? You know ... before we bought the small frac ... before we purchased that 130mm heritage ... before we got the 90mm Mak  etc etc . Of course aperture is king , i'm sure its written in the Old Testament somewhere . But the truth is that no matter what size scope you have , seeing a planet a lot closer than with the naked eye is amazing . Teasing a bit of detail from Jupiter or Mars in a small scope is in fact just as satisfying to the observer as  is wheeling around a huge Dobsonian  ( i have done both ). Seeing a crisp view of Saturn in a small apo refractor when you positively see the cassini division is amazing .  Preaching to the converted ? Maybe its a timely reminder . 

If you want to see the best views then get the biggest scope, AS LONG AS CONDITIONS ALLOW  . Although i favour Chris ( Lockie's) viewpoint in that the OP has a great planetary scope already . 

The real question is surely , what are the cons as well as the pro's in buying a large scope like , do you intend to to travel to a dark site ( larger aperture dobs will also increase the light pollution in a light polluted area , moving them to a dark site can be a pain ) . 

What about the increase in Mount size to cope with a 180mm Mak ( as well as cooling time )

 

 

Edited March 31, 2021 by Stu1smartcookie

[RobertI]

An alternative (and possibly cheaper) approach might be to consider bino-viewers with your existing Mak 127. Many folk (including me) find the ability to use two eyes makes a massive difference to what you can see when observing planets, moon and sun. I am constantly amazed by what my 102ED frac with binoviewers can achieve. 

Edited March 31, 2021 by RobertI