Saxon Maksutov-Cassegrains? Hi

[Scel]

Hi
I'm looking at upgrading from my Guan Sheng 8" Dob to something on an equatorial or GOTO mount for easier viewing of DSO's and occasionally moon and planets. I am considering a number of options including an equatorial platform or GEM for my existing OTA, however I've seen some cheap Maksutov-Cassegrains around and wondered if anyone had any experience with Saxon's 15019 (see link below).

http://www.saxon.com.au/products/product-details.php?productid=10247

Can anyone comment on the quality of Saxon scopes (even if you have only had general experience with them, but especially if you have used their Muk-Cas systems)?

I have never used the catadioptric scope before - is there a noticeable difference in image quality compared with a good newtonian? Or is the main advantage of the design mobility/storage.

Any advise is much appreciated.

[Astro_Bot]

I have an 8" Saxon Maksutov-Cassegrain on a GEM. I think it's a pretty good scope for the money. The focal length is long at 2500mm for me, so not for wide angle use - even with a 42mm 65 deg AFOV eyepiece, that's still only 1.0 degrees TFOV at 60X. For the one you're looking at (FL = 1900mm), that same eyepiece would get you 1.4 deg TFOV at 45X. It excels at the other end, though, with a modest 6mm eyepiece giving you over 300X (on the rare nights seeing permits) or a 9mm giving 200X, etc.

The MCT has it's advantages - relatively flat field and tolerant of simpler eyepiece designs. They're also robust and there's no need for user collimation, and well sealed so only the front corrector needs occasional cleaning. Theoretically it'll have better contrast than an equivalent aperture Schmidt-Cassegrain or Ritchey-Chretien, though it's pretty difficult to tell the difference side by side. Also, theoretically, it'll take longer to cool down, though I've not yet had a problem with tube currents (maybe because it takes so darn long to set up my mount .... ). The MCT makes a very good planetary scope, and isn't bad as a "grab-and-go" scope, even at 8", IMHO, but more so at 6".

It's certainly more transportable than a Newtonian of similar aperture, especially if you don't have a free back seat in your car - all my gear, mount included, fits in the boot of a medium-sized sedan.

Some Saxon packages do look a bit under-mounted (and I also read that somewhere else), so it might be better to buy the mount and OTA separately - The MCTs are a little heavier than their size suggests. The product page you link to states that the 6" tube weight is 1.37kg, but that's way off - my 8" weighs in at 12kg.

(Oddly enough, mine may go up for sale in a few weeks if my tax refund is as large as I'm hoping, thus allowing me to get something bigger. :) There's nothing wrong with the MCT, but 8" is as large as it gets, AFAIK, whereas I can get an 11" SCT or 10" RC on the same mount, or mix and match OTAs for imaging ... I'm still deciding).

Saxon makes at least some decent stuff and their products get picked up by other brands as well (I sometimes recognise them in ads under a different name). Whether the quality I've seen (i.e. decent, no problems) applies to their whole product line up, I don't know. As has been misreported elsewhere, Saxon is not Synta - Saxon-branded products in Aus come from AZT International Pty Ltd, which appears to be an Australian company linked to (but not necessarily owned by) Saxon Import & Export Pty Ltd and Sax Optics Co. Ltd (both in China).


I'll get the popcorn ..... ;)

[Astro_Bot]

Oh, that was remiss of me ...

Welcome to Ice In Space! :welcome:

[Wavytone]

OP...

Pro's:

- compact size compared to say f/7 8"Newtonian
- buckets of magnification, which is great if you are into lunar & planetary;

Cons:

- small field of view, terrible if you want wide rich-field views this is not for you*;
- tube currents will degrade the seeing while the scope cools down. But when it does cool down an f/15 mak is fantastic, far better than any SCT.

Lastly:

- rethink your eyepiece collection to suit the long focal ratio. I have a 180mm f/15 Mak and my eyepieces range from a Vixen 2" 50mm (lowest power) - this a huge hunk of glass the size of a half a house brick. In average seeing I can use a 13mm eyepiece, if the seeing is good I'll try 8mm and on really exceptional nights 5mm (maybe once per year).

*my solution is a side-by-side mount with a 102mm f/7 refractor to provide rich field views. With a focal length around 1/4 that of the Mak, it is an excellent "super finder".

[Scel]

Thank you both for such fast and detailed responses!!! Astro bot, please let me know if you end up selling :)

[Astro_Bot]

Great minds think alike - I (now) have an ED80 refractor for wide-field, too.