Jump to content


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Skywatcher Skymax 90

  • Please log in to reply
5 replies to this topic

#1 MrGuGuZai


    Lift Off

  • -----
  • topic starter
  • Posts: 11
  • Joined: 28 Mar 2020

Posted 03 April 2020 - 01:58 PM

anyone owned Skywatcher Skymax 90? can give me some reviews or problem with this scope?

#2 vtornado



  • *****
  • Posts: 2,727
  • Joined: 22 Jan 2016
  • Loc: Northern Illinois

Posted 03 April 2020 - 03:46 PM

I had the 100mm skymax, fine scope. 


Like all Maksutov's the front corrector is subject to dew and frost.   Depending upon how humid your air is,

you may need a dew shield or if you are a Floridian you may need a dew strap.


If removing it from a warm house to the chilly outside you will have to let in acclimate for 30 minutes OR wrap it with insulation.


If you are a new bee and live in light pollution and this scope is on a manual mount, star hopping is difficult.

#3 Abhat



  • *****
  • Posts: 2,250
  • Joined: 14 Dec 2013
  • Loc: Central Maryland, USA

Posted 03 April 2020 - 03:56 PM

Also like any other Maks these scopes are pain to collimate if for rare reasons they go out of collimation. I had to send one back to Orion my 90mm Mak few years ago. Because I was  original buyer they did it free of cost for me. That is why I stay away from used Maks. I don't want to own a scope that I do not have ability to collimate.

#4 sg6



  • *****
  • Posts: 7,693
  • Joined: 14 Feb 2010
  • Loc: Norfolk, UK.

Posted 03 April 2020 - 04:28 PM

1250mm focal length so the widest you will get is about 1.2 to 1.25 degree view.

Dew is notorious on Mak/SCT scopes.

You need tracking/goto as objects move out of field fast - A small jupiter would be center to edge in 2 minutes. So if manual you would be adjusting every minute in reality. And that would be the widest field you can get so slowestrate across.

Focusing is slow. The threads are small and it takes lots of turns to move the mirror.

There is very little you can do to improve it, 2" eyepieces are out of consideration you would have to replace quite a bit of the scope and would still likely get vignetting. Maybe not a problem, means you don't have reason to think of altering one.

Cool down gets reported as a problem - I basically ignore cool down. Mine gets what time is available while setting up and then I get viewing.

See lots of reports of people collimating them, if necessary it is a pain. Equipment is needed. As is knowledge.


Many scopes are becomming "specialised" these days. Maks and SCT's are owing to their inherent design and operation one that I would say are such.

#5 Shorty Barlow

Shorty Barlow


  • *****
  • Posts: 2,230
  • Joined: 15 Sep 2015
  • Loc: Lloegyr

Posted 03 April 2020 - 06:22 PM

I have the Orion version, they're both Synta.




I've never had collimation problems with any of my Synta Mak's.




AFAIK collimation problems are rare on Mak's and they are quite resilient. The focusers are actually pretty good, although I like a fine focus diagonal helical focuser as well.


It's bollocks to say you can't track with a small Mak. I've just been easily tracking lunar targets with a 102mm Mak at 217x on an alt-az and I'm physically disabled (partially paralysed).


You'll need a dew shield but a 90mm Mak will give superb lunar views, decent planetary views and you'll be able to see some of the brighter DSO's like M42. Splitting binary stars is also good with a Mak.




Field of view isn't wide though and rich field viewing is virtually impossible. A 2x reducer threaded into a 25mm Plossl eyepiece will give a wider exit pupil and lower magnification.

  • BFaucett likes this

#6 barbarosa



  • -----
  • Posts: 2,450
  • Joined: 11 Apr 2010
  • Loc: 139 miles W of the Awahnee Hotel

Posted 03 April 2020 - 06:49 PM

Not owned that model but I would expect that all of the 90 mm Maks that do not say Questar are going to be very much alike. SW, Celestron or Orion they are all from the same factory. The Celestron 90 mm Mak has a very long thread on CN mostly from folks who like it.


I just sold an old Meade 90mm Mak. The USA made scope had good optics, often compared with Questar; I would rate is as not better or worse than a run of the mine 4SE.   Ed Ting has his own opinion in his comparison of the Questar with the ETX90 and the C-90.


If you are concerned about the field of view, which as already said isn't wide go to Astronomy Tools and use the FOV calculator to see how large a particular target will appear in a particular EP. 

Edited by barbarosa, 03 April 2020 - 06:52 PM.

  • BFaucett and Barlowbill like this

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Recent Topics

Also tagged with one or more of these keywords: Maksutov

Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics