New Saxon MAK 8"

[JohnH]

Has anyone had hands on this new scope yet?

http://www.saxon.com.au/new.html#m20325

If yes care to comment? If no do you have opinions on the smaller Saxon MAKs ?

While on the subject opinions and experiances with MAK vs SCT designs at the 8" size would be appreciated. AFAIK the MAK has better contrast (smaller central obstruction) and longer focal length (thus higher magnification for any given ep) so is better for planetary/moon observing but is heavier (hence can give cool down problems) than equiv SCT.

To me this means an 8" MAK is close to a 9" SCT in light gathering, but what about for use with DSOs and astrophotography? I understand MAK's longer focal length is an issue (f12!) that means using a flattener/reducer is more often (always?) required but does this degrade image quality with DSOs a little or a lot, how much is a good reducer etc etc?

[dhumpie]

Wonder if it is made by Synta. There are many different sized MAK's out there now but so far the ones from Synta seem to be the best (the original ones that Orion USA were selling). The new ones that Celestron were selling prior to being absorbed by Synta did not receive very good reviews.

Darren

[miketheobscure]

It has been suggested it’s made by a company called Bosma, also from China, but that’s just a rumour at this stage.

I’d love to read a review too. I suppose this is pretty much direct competition for the 8” SCTs, rather than the Meade 7” Mak or 10” SCT, both of which also have c. 100" focal lengths, but are much more expensive.

Andrews has an add in the September Aus Sky & Tel for the OTA for $1199, which I think includes rings finder & a diagonal, but that may be wrong. By way of comparison, and without looking very hard the best 8” SCT OTA prices I could find were $1697 for the Celestron (telescopes-astronomy) and $1579 for the Meade (bintel). Assuming you don’t already have the rings (compatible dovetail etc) then that’s still an OK discount.

Quality I suppose will be the key.

Regards, Mike

[h0ughy]

I have been looking itnto these scopes and yes I agree, it does come down to the quality and finish. I was looking at purchsing a Williams Optical refractor (either a Zenithstar or the megrez) but saw this and started to wonder about it myself. it would make for an excellent planetary scope!

[miketheobscure]

Well, you’ve already got the 12”f/10 for planetary, the wide fields must be pretty tempting. I’ve only got 48” f.l., and halving that again isn’t what I’m after, though one of those small refractors might eventually come my way as a guide scope, or finder.

Next stop for me, and this at least a year down the track, is a better planetary scope. So far my thinking, without meaning to diss anyone's favourite design, is: Expensive APOs and boutique Maks are out on cost, a bigger newt is out on handle-ability, a much bigger SCT is out on cost & handle-ability. My current front runners are this Mak, if it turns out to be OK, the 9.25” Celestron and the 10” Meade.

Does anyone know how importing works? Is it just a matter of paying GST on personal imports, or are there duties too? By my reckoning, with GST and about $500 (guess only) on postage I’m still only at c$2300 for the 9.25 with carbon fibre & star bright, which is about $500 better than the best local price I’ve seen. Enough for another nice EP. :D

Regards, Mike

[iceman]

You'll have to pay Customs Duty, which isn't too much, $50-$100 I think, then 10% GST, + postage of course.

And then hope you don't have any problems with it and have to return it!! :doh:

[h0ughy]

Dear David

Thanks for your enquiry regarding the SAXON 8" MC.

This scope's not been available to us for long and we don't have pictures we can send you, apart from what's on our website for this model (www.saxon.com.au). The shots show just about all there is to see of the front element and the rear cell, but if you have queries about specific aspects of the unit, please get back to me.

A few details: the secondary spot is about 56mm diameter, the corrector is held in place by a plastic ring and secured by philips head screws. It is reasonably easy to remove if cleaning is ever required. The corrector has standard MgF coatings on both sides.

The rear cell has three ports (with rubber caps) for access to collimation screws, and the standard SCT threaded mount for fitting diagonals, etc. The focus knob has a smooth action with little mirror shift.

The mirrors are aluminised and overcoated. There is a baffle attached to the secondary, and additional baffling with the primary.

The OTA has no mounting points (except for the finderscope) and needs the supplied rings to fit to the equatorial head. There are flats on the tops of the rings that are drilled and tapped, if accessories need to be added.

These scopes are comparable to the Meades in specification, manufacturing tolerences, coatings and quality control. They are imported directly from China, rather than via the USA.

Hope this has answered your questions.

Regards, Graham Hardy

SAXON Telescopes

ph (03) 9687 7750 fax (03) 9687 7241

[JohnH]

So I should consider getting an ED80 and this MAK on an EQ6 or HEQ5 + Skyscan for the best of all worlds (DSO/planetary both visual/photo) or I could skip the ED80 and get a Canon 70-200 f4L lens and eyepiece adapter. Guide with tube one - image with the other. Hmmm. Wonder what the MAK weighs compared to the 9.25 Celestron SCT?

[gbeal]

While not having seen or had anything to do with the "Mak" in question, I would like to point out that there are "Maks, and there are "Maks".
My Mak is a Mak/Newt, and this is a whole different kettle of fish.
Lastly, if you are after a C9.25, there is one for sale in Ozzie, which was advertised on Astromart yesterday, and very reasonably.
Gary

[miketheobscure]

Interesting info about importing guys, thanks.

Thanks for the heads-up about Astromart too, it’s a pity for me that 9.25’s come up before I have any money, but it’ll be a bargain for someone.

On your other point, sure, there are Mak-Newts and Mak-Cas scopes, but it’s the latter I’m interested in for the long focal lengths they offer. Incidentally there is also a Mak for sale on Astromart, but it’s only a 5”, which might be a good travel scope, but it only gets me an extra 2” f.l.

Regards, Mike

[mch62]

A well cooled well made mak makes a wonderful planetary scope but that's the catch ---cooled.
Intes micro and even the Meade 7"mak have cooling in the form of air holes and or fans in the OTA's.
As with any large hunk of glass and more so with an enclosed OTA getting the hot air out before the night is over is required for high power viewing.
The front meniscus lens on a Mak is considerable thicker than a SCT and requires a longer cool down time.
I don't own a Intes but have seen through a 7" f15 unit some time back and found it's planetary views excellent once cooled down, (a 1.5hrs job with fans running) but there not cheap imported into OZ , but are very well made.
The smaller of the Chinese Maks seam to get mix reviews but generally acceptable but my only concern is cool down.
Personally I would prefer a well made 8" f8 planetary truss Newt for the price.
Less central obstruction and heat problems and if a well made mirror is used ( relatively easy at f8 and .95 SR or more) will be better than any Chinese mass made jobs and still short enough and light enough not to pose any real problems for an EQ6.
Remember in any Cassegrain design getting a good primary at the f2's used , requires excellent manufacturing skills even for a spherical primary.
I would like to see the Strehl Ratio of the optics if they can supply them for the Chinese Mak's but the standard Intes are 1/6wave .
The delux units are 1/10

Bang for your buck you can't go past a Newtonian but for a quality Mak the Intes are very good..

Just my 5Cents worth.
This will stir the pot :poke:

Mark


Commonly Encountered Wavefront Relationships of single surface

pv : pv decimal : RMS : Strehl Ratio

1/3 : .333 : .094 : .71
1/4 : .250 : .071 : .82 Rayleigh Limit
1/5 : .200 : .057 : .88
1/6 : .167 : .047 : .92 Good
1/7 : .143 : .041 : .94 Very Good
1/8 : .125 : .036 : .95 Excellent
1/9 : .111 : .032 : .960 (.96) Excellent
1/10 : .100 : .028 : .969 (.97) Excellent
1/11 : .091 : .026 : .974
1/12 : .083 : .024 : .978

[miketheobscure]

It’s interesting that you should bring up Cassegrains. I know it’s not what you meant, but one possibility I’m looking at is rebuilding my Newtonian as a classical Cassegrain(ian). I’d need to get a suitable hyperbolic concave secondary, and I’ve had no luck at finding one so far. People who know a lot more about optics than I do have also said similar things to you, about getting a better long focal length newt and coupling it with a good Barlow, but that doesn't fix my problem with a Newt's eyepiece location. Makes it slightly worse in fact. :rolleyes:

Royce does Cassegrain sets, out of interest ( http://www.rfroyce.com/cass_sets.htm ) did you get your mirror straight from him, or via some other route?

About the EQ6, I’m not worried about its weight bearing capabilities, I’m worried about mine! :ashamed:

Regards, Mike

[mch62]

Hi Mike not knocking Classical Cassegrains as they have there place as do other designs but when i was doing my reseach for my scope I hade a good conversation with Rob Royce about doing a 12.5"Classical Cassegrain of f24 for planetary work as I liked the design location of the eyepiece and shorter OTA from my SCT days but wanted better quality than the commercial SCTscopes.(sorry guys)
Rob said he would do it but insisted that a Newtonian was a better way to go.

Even at f24 and a primary of f5ish the central obstruction was still in the order of 24% and the cost goes up a fair bit for that extra little mirror out frount.A more involved process than a flat diagonal.
The OTA is also more involved with good baffling required .

A planetary optimised Newtonian of f6 or more will have a central obstruction of well under 20% and is easy to contruct.

The man (Royce)could make any scope design that he wants but his own scopes include an 10"f8 and f6 Newtonians + a rather long refractor..

He now offers Cassegrain mirror sets as a standard item for those that must have such a design but from all his writings on his web pageses it is obvious to see he favours the Newtonian.

The best bang for your buck and versatile design.

I am very happy with my RR Newt conical mirror and even though the scope is optimised for planetary work with carefull designing it also works just as well for deep sky.
A CCass is really best suited to planetary use unless you go the expensive Ritchey-Chretien short F ratio then that is more orientated towards deep sky imaging.
I have just learnt to live with the 2m OTA asssembly of the 12.5"and have had to make a mount for it.
If you go to the Rob Royce web site you will see a 10"f6 double truss Newt on an EQ6 with all the instructions to make the scope.
This is about the practical limit for an OTA on the EQ6.

http://www.rfroyce.com/10f6tel/

If your worried about the eyepiece hight of say this 10" scope remove the EQ6 legs and make a low hight pier.
There is room for the scope to be mounted lower as you can see from the pics on his web page.
Your scope is an 8"f6 from your signiture so ep hight should not be a problem if you make a low pier for the EQ6.

Hope this help
Mark

[gbeal]

I agree with Mark.
The good quality newt is hard to beat.
I still favour my Mak/Newt though, and I guess it is just what you want, and expect from a scope. The long focal length issue that someone raised in the Mak/Cass design can also work against you. Try using it for a slightly wide field view and it requires an excessively long eyepiece. Whereas with the MN design, you simply crank it up with a Powermate mate.
I do tend to disagree with Mark on cooldown. I have had a zillion Maks, OK, not a zilliuon, but a few. I have never had a problem with cooldown. BUT.... I do set up before having an evening graze, and by the time the dishes are done, the scope is ready. My gear is also stored in a workshop in the hanger, and is close to ambient.
I would agree that if you took your scope from the inside of the house, warm and dry, and out into the cool of night there maybe a problem, but wouldn't there also with any optical system, newt included. A little preparation is all that is required.
Gary

[mch62]

Hi Gary is your mak newt got vent holes for cool down , as every Mak Newt or cass that I have look through with a seal tube has taken a long time to cool down .Longer than it takes me to do the dishes :D .
I suppose if you keep the scope close to the out side ambient the differential won't be as great but if you can't??

The intes Mak cass unit I saw a few years back with the ventalation holes in frount didn't seam to have as much of a problem with cool down.

Now the semi sealed tube does have advantages of keeping the optics relativly dust free and of coarse the Miniscus correction , but the later can be done with a coma corrector for shorter focal ratios Newtonians.

The open tube of a Newt weather it be a solid tube or truss does offer a more open path for mirror heat to escape.

[miketheobscure]

A pier is a possibility I'd considered, but a long focus Newt is a whole new scope. A major part of the attraction to me of the clasical Cass. design was that the only expense would be the new secondary & spider, my thinking was that it would be the cheaper option. However ...

The difficulty in procuring (and certainly in making) a convex hyperbolic secondary's moved me on to the simpler concave elliptical secondary of a Gregorian. :D Perhaps it's the siren song of mirror grinding, I don't know. :shrug:

In any case, I seem to have strayed off the topic of the Chinese Mak, just a bit. Apologies to anyone trying to follow threads.
Regards, Mike

[JohnH]

Interesting discussion folks...but off topic now and belongs in the ATM forum. Original idea was to find the niche for the new 8" MAK given the low cost of this OTA. I gather that consensus is that a MAK is good for planetary vs a same appature SCT but has cool down issues and is not so good for DSOs. An SCT is a better general purpose instrument and if you want the best visual/photography SCT (for a reasonable $$$) you are best going for the Celestron 9.25. Alternatives to this are NEWT and MAK_NEWT but these are not so portable. However this OTA is <<<< $ than the celestron so for $1000 or so and a desire to do visual and photographic work on DSO and planets from a suburban back yard where would your money go (must be portable too!)?

[mick pinner]

l think it depends on what your all up budget is, if you spend say $1400 on the Mak 203 x 2500 on an EQ5 by the time you add goto for tracking, buy a camera for photography, add a guide scope or off axis guider and a few good ep's for visual work you would spend $5000.00 easily and this is on a realitively small aparture although portable scope. lt's just my opinion but l would direct anyone getting into this who wants to do photography from the outset on a budget to buy a second hand scope, for some reason second hand astronomical pieces of equipment don't seem to hold value and there are some bargains to be had if you look around.

[gbeal]

Hi Mick,
I guess then that I have significantly more dishes than you.
Yes, the fact that the scope is near ambient anyway helps, and the placing of it "out" ready to observe is all that is required.
Mine has the "wholey" meniscus cell, and also the rear of the primary fan, but I have never used it. Maybe I should try it.
While my experience may not be the same as anyone/everyone elses, I have never had a cooldown issue with any of my Maks, both Mak/Cass, and Mak/Newt.
In as much as budget though, certainly with a Mak/Newt factor in an equal amount of cash for the mount, as they demand a bigger more robust mount than any Mak/Cass of similar aperture.
Newt, and especially longer focus newts, are the same, a long lever arm. I normally describe my Mak/Newt as a newt with an expensive see through secondary holder, and without the diffraction spikes.
It would be good to have a crack at one of these new Chinese Mak/Cass scopes, as their Russian cousins are unbeatable. The advert in the latest Sky & Space at first glance made me think they were from Russia, for some reason, but I now don't think this is correct??
Gary