Do I need to collimate this thing???

[Shore Diver]

So, I finally got to try out my new Meade NG90 Maksutov Cassegrain telescope tonight. My excitement quickly went downhill after putting in the 9mm lens and looking at Jupiter. I couldn’t get it to focus at all. The best I could do was get it to be a small blob instead of a spread out blob. When I switched to the 26mm eyepiece, it was better, but noticeably not as clear as my 70mm Celestron. The bands around Jupiter were not distinguishable. I could see the ring around Saturn with the 26, but it wasn’t very sharp. The 9mm was awful.

So, any advice on how to collimate this thing, or should I let a professional do it?

Edited July 30, 2020 by Shore Diver
Typo

[fwm891]

Does the focuser allow you to move inside and outside the 'focus' position. If your up against a stop at one end of the focuser's travel you may need to simply look at adding/removing spacers to allow the eyepiece to focus. As it's new it should be optically sound - talk to the retailer about an exchange.

[Cosmic Geoff]

A note for anybody posting about Meade telescopes: please include at least the aperture in your post as it is not obvious from the model name.

Apparently this one has an aperture of 90mm.   What Shore Diver describes could be normal for a telescope of this aperture, especially if it has not had time to cool down to outside temperature.  The planet is very low and the 'seeing' at this altitude will be bad. Maksutov telescopes in general need a dew shield to prevent dew forming on the corrector plate - telescopes of this design are notorious 'dew magnets'.  It may be worth trying alternative eyepieces as with other makes of telescope the kit eyepieces supplied as starters are of poor quality.

Even with an 8" SCT I cannot see a lot of detail on Jupiter.  I confess to not being a very skilled visual observer, but I cannot see much more than a bright disk and a couple of cloud belts.  Imaging with the same 'scope reveals more. 

[andrew s]

Have you focused on a terrestrial scene was it ok, what about a star near the zenith in focus and  inside and outside focus? This will help you decide what if anything needs doing. 

It could be seeing or the other issues mentioned above.

Regards Andrew 

[Craney]

All good advice above.

Do a de-focused star test to see if there are collimation issues. 

I used to have a Celestron C-90 and it was pretty resilient in terms of collimation and traveled with me quite a lot without any problems.

The following GIF file is from my C8 Edge the other night.  I just may have the worse see-ing on the planet !!! 

This is Jupiter at it's 'zenith' of  +13degs over the adjacent house.

I'm rather suspecting the neighbour is using a thermo-nuclear device as his central heating boiler.

 

Edited July 30, 2020 by Craney

[AstroMuni]

27 minutes ago, Craney said:

I'm rather suspecting the neighbour is using a thermo-nuclear device as his central heating boiler.

🤣 and that too in summer!

[Shore Diver]

I have my Telescope in the garage. It's the same temperature as it is outside, as the windows and back door are open during the day. The windows are open all night, so there is never any sudden temp change. Also, i tried focusing on the moon first. Not as sharp as i would like it to be, but still sharp. Just to make sure it's not the eyepiece, i tried the 10mm one from my Celestron Astromaster 70. Same thing.

Sorry about not putting in the specs of the Meade! here's a link to all the info: Meade NG90

[andrew s]

You will get a lot of poor seeing due to the heat given off by your garage floor, wall etc.

The building will not cool as quickly as the night air causing increased turbulence. 

It's not rearly a fair test of the telescope. 

Regards Andrew 

 

[Cosmic Geoff]

Another possiblility is that the eyepieces are not very good.  'MA' eyepieces are not the sort of thing one would buy in the aftermarket, and the eyepieces supplied with kits are basic, cheap to manufacture to keep the kit cost down, and just intended to get you started.  The same applies to the Celestron kit eyepieces.  When I upgraded from the 9mm eyepiece that came with my 127mm Mak, I found an immediate and obvious improvement.

It is possible that the Meade needs collimating, but Maksutovs rarely if ever need adjustment.  It would be prudent to check with a star test in case you got a bad one.