Orion / Intes Mak-Newt

[John]

This mean looking little black number is my new-to-me Orion Argonaut which is a 6" F/6 maksutov-newtonian design. Even though it bears the Orion branding the scope is the same as the Intes MN61 and is of Russian manufacture. Thanks to Tony (whippy) for carefully packaging the scope so it got me in good order

With it's small secondary obstruction (29mm = 19% of primary diameter) but fast focal ratio these scopes have the reputation of being very versatile - I'm looking forward to finding out for myself

A new scope, a new eyepiece (Nagler T6 2.5mm) and clear(ish) skies - what more could I ask for

[Deneb]

It looks like a really nice stealthy scope John...

Nadeem

[barkis]

Looks a class act John, I'm sure this instrument will do the business.

I know Tony has always thought very highly about the MN Scopes.

There will be some good posts heading our way when you press it into service. If you're going to Kelling,, I would really like a peek or two. If not, then perhaps Lucksall In April.

Ron.

[Doc]

I'm liking this one alot John, I have a soft spot for the Intes.

[John]

Looks a class act John, I'm sure this instrument will do the business.

I know Tony has always thought very highly about the MN Scopes.

There will be some good posts heading our way when you press it into service. If you're going to Kelling,, I would really like a peek or two. If not, then perhaps Lucksall In April.

Ron.

I can't be at Kelling Ron - but will definately be at Lucksall - and for a couple more nights hopefully

You, and anyone else who is interested, are more than welcome to have a look through it

[Whippy]

Looking good John, glad it's gone to a good home .

Tony..

[dark star]

I have the Intes MK 66 Mak which I love.

Intes scopes are great, I think you are in for a treat!

[Wobbly Bob]

One of the best views I have of Saturn, was through an Intes. I am sure you are going to love this scope.

[A McEwan]

Hmmm.... mount a second one on the other side of that mount, set up near an airport... and prepare to be arrested!

[Moonshane]

stunning looking scope John - well done for finding and getting one

Based on what I have heard of these scopes I bet the performance will be superb.

Just for my education, what's the 'point' of this design. I.e. what does the glass in the tube 'do' (this is a genuine good natured enquiry to understand how the design works and not a criticism of your new baby!). I am comparing it with the newt design mainly as I'd always assumed Maks have a longer focal length but this has the sort of FL I'd expect from a newt.

cheers

Shane

[Whippy]

Just for my education, what's the 'point' of this design. I.e. what does the glass in the tube 'do' (this is a genuine good natured enquiry to understand how the design works and not a criticism of your new baby!). I am comparing it with the newt design mainly as I'd always assumed Maks have a longer focal length but this has the sort of FL I'd expect from a newt.

cheers

Shane

It's basically a newtonian with a full aperture corrector on the front of it. Imagine a Baader MPCC at the front of the scope instead of in the focuser. What Intes have also done with this is use a tiny secondary to maximise contrast which is essential for ciritcal planetary/lunar observing, but instead of the cassegrain design with it's folded light path and long focal length, the Mak-Newt is faster and shorter so it's quite a versatile scope.

The only real downside to it (apart from the weight) is you can't have very widefields with it because the secondary isn't big enough to fully illuminate low power EP's. FWIW, in terms of contrast and image quality, the only scope I've found that beats it is a refractor.

HTH

Tony..

[Moonshane]

cheers Tony - perfect explanation I understand now.

it sounds very similar to my 6" f11 but obviously faster and without the coma you'd normally get with an f6 newt.

no wonder John's chuffed

[John]

cheers Tony - perfect explanation I understand now.

it sounds very similar to my 6" f11 but obviously faster and without the coma you'd normally get with an f6 newt.

no wonder John's chuffed

Thanks for the explanation Tony - better than I could have done

This link is also quite helpful:

Starizona's Telescope Basics

The lack of coma is something I've noticed during my 1st light session with it - pin point stars right to the edge with my Nagers and Ethoi. From what I've read, there is some coma in the design but it's around 70% less than a conventional newtonian of the same aperture / focal ratio.

Noting what Tony says about wide field views, in between gawping at Jupiter, I've had a quick look at M31 and the double cluster in Perseus and been rather impressed with the views there as well - even with my 31mm Nagler, where the eyepiece field stop is larger than the scope diagonal !. If there is some loss of light at the field edges, it was not noticable to me, but it was my 1st night with the scope.

The most prominant feature of the scope though has been, as the reviews suggested, the refractor-like star images. They look to me like textbook images - tightly defined airey disks with a single faint diffraction ring and no diffractions spikes of course. Either side of focus you get a nice concentric set of diffrcation rings which look more or less identical either side of focus. I'm not an optical expert but I heve a feeling these are symptomatic of really well corrected optics

As the nights get cooler I'm going to need to manage cooldown more carefully with this scope - I'm intending to fit a cooling fan to the rear of the primary mirror cell to help with that (there is a removable plate on the back of the scope for which looks designed for that purpose).

I'll post some more reports on the scope when I've had more time at the eyepiece - one night (albeit a rather good one ) is not much to go on.

[Moonshane]

this sounds excellent John. for now I'll stick with my 6" f11 newt but this is something to consider in the future. At £114 plus some fuel I am quite happy with mine too, especially with HILUX/ 1/6PV which was a nice surprise when I checked the mirror yesterday!

my experience of that scope (25mm secondary) is like yours as the double cluster looked great in that in the 35mm Pan so I don't think this is something to 'worry' about.

I was surprised you use a diagonal with it. does it give a correctly inverted view?

I bet a fan would help. on my big dob, I keep the caps on and blow the air out of the focuser. works a treat and would probably work well on this design too?

[John]

...I was surprised you use a diagonal with it. does it give a correctly inverted view?

I bet a fan would help. on my big dob, I keep the caps on and blow the air out of the focuser. works a treat and would probably work well on this design too?

Sorry, sloppy posting there - I meant the diagonal mirror (secondary) that's part of the scope.

Yes on the fan arrangement, that's how I think it will work with the mak-newt as well.

Your OO 6" F/11 was an exceptional buy Shane - as it's Hilux coated and 1/6 wave you may well not need to consider a further optical upgrade. Curved secondary support vanes and some tactical flocking might be worth considering if the scope does not already have these features.

My 10" F/4.8 OO newtonian has Hilux and is 1/6 wave as well. The Hilux in particular does make a noticable difference in light transmission I feel.

[Moonshane]

ahh sorry John - it was me being a bit thick!

it would be great to compare the two scopes side by side some day - I must get down to a star party at some point in my life!

I agree that I may not have to improve the optics - this is a major bonus and means I can fund another Ethos sooner than expected!

[karpana]

Firstly, I want to apologize for hijacking a somewhat 'older' post (nearly three months old; without any activity)

@ Moonshane,

I'm new to Stargazerslounge, and chanced upon your post from a quick google search on ways to cool down my 190mm Mak-Newt.

I live in Central Canada, and as you can well imagine winter is in full-swing. I've recently purchased my 190mm Mak-Newt and like all my scopes they are kept indoors when not in use. Unfortunately, with the meniscus, I'm finding that the optics are taking a while to cool down. A lot longer than I had anticipated considering the temperature differential of nearly 35 degrees celsius.

I'm wondering if you could expand upon your comment below:

On my big dob, I keep the caps on and blow the air out of the focuser. works a treat and would probably work well on this design too?

Specifically, I'm wondering what you mean, and how this works, to see if I can jury-rig something of a similar nature myself for my mak-newt.

My thoughts for cooling were to mount an 80mm fan behind the primary, and install a second fan on the eyepiece holder to draw cool air through the scope (up from the primary and out the focuser) in an attempt to prevent settling of any dust or other airborne debris on either the primary, secondary or back side of the meniscus. Unfortunately, but I'm not sure if this is a good idea or not.

Looking forward to hearing back.

Thanks,

Paul.

[Moonshane]

hi Paul

broadly I do what you are suggesting although I don't use the extracting fan as it's really not needed - there's a fair breeze blowing up and out of the tube without the need for extraction.

if you put a filter over the fan at the primary end then I think you'd remove the potential for dust? I don't filter the fans and have not had a problem with dust although I see the problem with the Mak-Newt meniscus. hope this helps.

[John]

Firstly, I want to apologize for hijacking a somewhat 'older' post (nearly three months old; without any activity)....

No problem Paul and welcome to SGL

Just a suggestion though - I'd post this query as a thread of it's own under the "Equipment Help" section - you will get more responses that way

[karpana]

Thanks Moonshane...much appreciated...

Thanks Jahmanson...I'll follow up your recommendation...

[Bodkin]

That looks really good John. I have one of these weighty beasts and am looking to change from a Losmandy GM8 to a more portable alt-az mount. How do you find your one? Any recommendations?

[John]

That looks really good John. I have one of these weighty beasts and am looking to change from a Losmandy GM8 to a more portable alt-az mount. How do you find your one? Any recommendations?

Thanks Jonathan

I'm a big fan of alt-az mounts and only use an EQ if I really must. The alt-az I use for my mak-newt was made by Ambemille engineering but it's out of production now. It's very similar to the Giro mounts and can take a 10kg optical tube on either side if needed. Since the photos were taken, I've swapped the tripod for a 2" steel tubed one which is even more solid. It's a great setup as you can put the eyepiece just where you like it most for sitting or standing observing. As an "old hand" with alt-az mounts I'm quite comfortable with the nudge-drift method at high power - but I do use Ethe and Naglers so the drift is a bit longer with those !.

Is your mak-newt one of the Intes or Intes Micro ones ?. I'd be interested in comparing notes on them, especially collimation.

[Moonshane]

my mate has a Intes-Micro MN78 and it's an awesome beast. We are going to have a shoot-out with my 6" f11 which I expect to lose but it will be interesting to see the difference between his and mine in terms of the images attained.

[John]

Update photos - the scope on the 2" CG5 tripod now and fitted with a Baader RDF in place of the 9x50 - there are 2 finder mounting points provide as standard (which is a thoughtful touch) so it's easy enough to fit both and optical finder and an RDF. While the finish looks "utility" the quality of the engineering is first class with every screw and bolt fitting precisely with no slop at all. I reckon that many hours of work go into making one of these things

[russ]

That looks superb John. I'm very envious indeed.