Purchasing additional scope advice

[milkyjoe]

Hi all,

I currently own a 4.5" refractor and an 8" dob, having viewed venus, jupiter and saturn through both I was not blown away by what I saw so I was thinking of buying a smaller/travel scope that will give me the same if not similar views; something like the Skywatcher Heritage 90 Virtuoso.  I am particularly interested in the tracking mount and it's applications.

Obviously, only having a 3.5" mirror, can I expect to see something like my attached image (taken with my 8" dob using a 2x barlow)?

Are there any other similar scopes anyone can recommend? :-)

Thanks in advance.

Richard.

[laudropb]

What magnification was the image taken at ?

[Cornelius Varley]

I think you will be surprised what a 90mm Mak will do.

[damnut]

Mak's make great grab & go scopes, however I use an ST120, as I like the widefield views it gives. Planetary though a mak or a small sct.

[milkyjoe]

What magnification was the image taken at ?

I've no idea, my camera was attached to a 2x barlow lens.

[milkyjoe]

Mak's make great grab & go scopes, however I use an ST120, as I like the widefield views it gives. Planetary though a mak or a small sct.

I've got a ST102, but the views are not that great.  I thought by having more aperture I would be able to see more detail on Saturn, but I was sadly disappointed.  Maybe my dob is more useful for deep space objects.

[Stu]

I've got a ST102, but the views are not that great. I thought by having more aperture I would be able to see more detail on Saturn, but I was sadly disappointed. Maybe my dob is more useful for deep space objects.

If you are getting views like your attached image then I don't think you are getting everything you can from your 8" dob. I don't get the point of buying something smaller as it won't give you views which are as good as the 8".

Saturn is not well positioned this year, and won't be for a number of years yet unfortunately, but surprising detail is still possible if conditions are right and you are patient.

Have you checked collimation, cooling and tried on various nights to get one with good seeing? All these things make a big difference.

In the 8" I would expect you to be able to see the A & B rings, possibly C plus the Cassini division on good nights. You should also see some subtle shading on the surface.

Take time at the eyepiece to catch the moments of good seeing. Which eyepieces are you using? Around x180 to x220 ish works well for Saturn on good nights.

Stu

[milkyjoe]

If you are getting views like your attached image then I don't think you are getting everything you can from your 8" dob. I don't get the point of buying something smaller as it won't give you views which are as good as the 8".

I'm getting better views than my attached image, this is all I could capture with my camera.

Saturn is not well positioned this year, and won't be for a number of years yet unfortunately, but surprising detail is still possible if conditions are right and you are patient.

Have you checked collimation, cooling and tried on various nights to get one with good seeing? All these things make a big difference.

Collimation is fine.

In the 8" I would expect you to be able to see the A & B rings, possibly C plus the Cassini division on good nights. You should also see some subtle shading on the surface.

I could only just make out some of the moons to be honest.

Take time at the eyepiece to catch the moments of good seeing. Which eyepieces are you using? Around x180 to x220 ish works well for Saturn on good nights.

I use 16mm and 25mm meade 3000 plossls with a meade 2x barlow.

Stu

So a 90mm mak would be no good then, as I said I am interested in the tracking mount also?

Thanks Stu.

[John]

I agree 100% with Stu. I've had some superb views of the planets with an 8" Skywatcher dobsonian. The motorising of the mount is an issue but I can't see a 90mm mak-cassegrain being able to match, let alone improve on, the planetary views that your 8" dobsonian should be giving.

A 150mm mak-cassegrain might get pretty close or an ED120 refractor maybe.

[Ju Piter]

i get fantastic views of the planets with my 130p(5 inch).collimation and making sure the scope is cooled enough really has made a huge difference i can see the rings moons and  a and b rings all at 130x the planets will always look small but the more you look the more you will see as our brains keeps the pics we see and then just enhance the next time we see them.dont have to high expectations of what you can see just get out and enjoy the wonders of the universe

[Stu]

Hi Richard,

I think it's best to treat the two things separately otherwise it gets confusing.

As said, a 90mm Mak will not compete with a 200mm dob for most things including planetary detail.

If tracking is important to you, along with the views the you would probably need to consider a much higher budget for something like a C8 or 8SE on a tracking/go to mount perhaps, or a tracking dob.

[milkyjoe]

Hi Richard,

I think it's best to treat the two things separately otherwise it gets confusing.

As said, a 90mm Mak will not compete with a 200mm dob for most things including planetary detail.

If tracking is important to you, along with the views the you would probably need to consider a much higher budget for something like a C8 or 8SE on a tracking/go to mount perhaps, or a tracking dob.

Hi Stu,

Yes, I realise the 90mm mak will not compete with my 8" dob, but it can be a faff setting it up and getting it "ready" for viewing.  It can take some time as I have to collimate it every time as I store it in my bedroom and have to carry it downstairs, trough the living room, through the conservatory and out into the garen, and not to mention it is pretty heavy!

I just thought with a grab-and-go scope like the 90mm mak on a tracking mount it would be a hell of a lot easier to carry it outside for one, and I would be ready to go much quicker, and be able to track objects as well, which is nice.

I can't afford anything like the C8 or 8SE unfortunately, much as I would love one of those.

I thought mak's of any size were best used for moon/planetary viewing??

Richard.

[Stu]

Hi Richard,

It is true that Maks tend to have a longer focal length with good contrast so make good planetary and lunar scopes.

They don't defy the laws of physics though , and so a 90mm mak is still a 90mm scope.

If you want a more portable scope, perhaps consider a 127mm Skymax or similar on a simple tracking mount. I think the extra resolution of the 127 would be worth it, and would give significantly better views than the 90 whist still being very compact and easy to set up. Often on ABS or even Astroboot so worth keeping an eye out for a bargain.

[milkyjoe]

Hi Richard,

It is true that Maks tend to have a longer focal length with good contrast so make good planetary and lunar scopes.

They don't defy the laws of physics though , and so a 90mm mak is still a 90mm scope.

That's a shame!

If you want a more portable scope, perhaps consider a 127mm Skymax or similar on a simple tracking mount. I think the extra resolution of the 127 would be worth it, and would give significantly better views than the 90 whist still being very compact and easy to set up. Often on ABS or even Astroboot so worth keeping an eye out for a bargain.

Unfortunately, my budget won't stretch to the 127mm Skymax.  Perhaps I could use a 90mm mak for solar observations (with the appropriate filer of course! ) ?

[happy-kat]

Won't stretch yet but could save for a bit.

What mount is your 4.5 inch on?

Only there is no reason not to investigate just buying the 127 ota and putting it on a different mount.

The eq1 is not up to it but what did your ST102mm come with?

For example I can mount all my scopes on my heritage 130p base then sit it on a table and view with say my refractor or MAK.

There is a 127 in the classified (don't know the seller).