Jump to content


Photo

Frustrated with 3.5

  • Please log in to reply
13 replies to this topic

#1 paulandrei

paulandrei

    Lift Off

  • -----
  • Posts: 7
  • Joined: 09 Jul 2014

Posted 12 July 2014 - 05:46 PM

Hi
I inherited a well used 69' 3.5 basic model some years ago. I have not been impressed with the proformance. I talked to someone at Company 7 about a cleaning. He mentioned that because of the age I might consider having it cleaned, and shelving it as an heirloom. He suggested I then buying a newer model with better tracking, optics, mirror, coatings, and eyepieces. Well *BLEEP*.
While I know this is an expensive hobby, I thought I could drop a few hundred here and there. I know my old eyepieces have some dust (not much), I was wondering if they might be the culprits. Am I expecting to much from this little, old telescope? I have seen some small refractors with ED glass and they are sharper than my scope.
Should I try updated eyepieces? With an adapter ?
The skinny is if I need any new coatings, glass, mirror etc I can't afford it. I can scrape the money for a cleaning or some eyepieces, but not both. Is there any tell tail signs that something specific might be wrong? I know these are some vague questions. Please excuse my ignorance I just want to love my telescope as much as others love theirs.

#2 munirocks

munirocks

    Explorer 1

  • -----
  • Posts: 80
  • Joined: 21 Oct 2013
  • Loc: Bourne End, UK

Posted 12 July 2014 - 06:17 PM

I'd first try to isolate the problem to see if the issue lies with the eyepieces or the scope. Try the eyepieces in a different scope (of the same f/14 speed), and borrow some other eyepieces to try in your scope. How does the main mirror coating look? Does it show any deterioration around the edges?

#3 paulandrei

paulandrei

    Lift Off

  • -----
  • Posts: 7
  • Joined: 09 Jul 2014

Posted 12 July 2014 - 11:55 PM

Hi the mirror looks good. The front optics have a few small blemishes. Maybe you can only expect so much from 89mm. I just need to make some telescope friends in my area, and compare scopes.

#4 cbwerner

cbwerner

    Apollo

  • -----
  • Moderators
  • Posts: 1491
  • Joined: 27 Aug 2005
  • Loc: Maidens, VA

Posted 13 July 2014 - 12:36 AM

A lot of things like this are driven by expectations and focus. If you expect more than is reasonable for the scope or are trying to do something the instrument isn't well suited for you're just setting yourself up for disappointment. That's why I think hanging with some fellow amateurs and using their scopes is so helpful - you can cover a lot of ground quickly in figuring out what you're after.

There is one pitfall to avoid in that, but it's controllable. The views are going to be great through that 16" Dob (going big to make my point ;) ), but how are you going to react to the setup, and even worse, the takedown? Does it fit your car easily? Is your schedule and your viewing habits truly going to accommodate the logistics required to truly use a larger scope?

For many the answer to those questions is yes. But there are also a whole lot who jump for that larger scope, and it ends up sitting unused in the garage after the initial thrill wears off.

That's why I cautioned in the other thread about letting the Q go too readily. It truly excels in the logistical department, from having everything you need in one small case, to a truly high build quality where everything works as it should with no compromises, to the simple beauty of the control box and it's ability to switch between finder, scope and Barlow views with 2 levers.

Now, my wife is a real bargain hunter, and will show up at times with purchases that are thoughtful but ill considered at the same time - like buying me a 4 lb. bag of a type/brand of coffee I don't drink because she thought the price was good. Well, it ain't a bargain if it's something I don't want.

That's your dilemma - you've got a real gem on your hands at a bargain (at least pre-cleaning or whatever, but likely after that as well). But it ain't a bargain if it doesn't fit what you want. Hanging with other amateurs and using their scopes will help you sort that. You should also read through the threads here and see what people do with their Q's - that will give you a better idea of how others enjoy their Qs.

To paraphrase a quip about boating, it's nice to have a big Dob or some other huge scope, but to my mind it's better to have a friend with a big scope. I get the big scope itch every now again; all it takes for me is a star party fix. I've never met an amateur astronomer who wasn't positively delighted to have others bask in the views through his/her scope.

Good luck, and I hope we'll see you back with more questions.

#5 dcriner

dcriner

    Lift Off

  • -----
  • Posts: 22
  • Joined: 08 Jun 2010

Posted 14 July 2014 - 06:25 PM

Why not send it in to Questar for an overhaul?

#6 munirocks

munirocks

    Explorer 1

  • -----
  • Posts: 80
  • Joined: 21 Oct 2013
  • Loc: Bourne End, UK

Posted 15 July 2014 - 05:17 PM

He's already answered that question in the original post.

#7 GR1973

GR1973

    Vostok 1

  • -----
  • Posts: 137
  • Joined: 29 Sep 2007
  • Loc: Pittsburgh,PA

Posted 15 July 2014 - 07:26 PM

Can you post some images of the mirror and the corrector so some of Q members could estimate the situation ?

#8 paulandrei

paulandrei

    Lift Off

  • -----
  • Posts: 7
  • Joined: 09 Jul 2014

Posted 16 July 2014 - 12:19 AM

Hi everyone and thanks for the support. I was wondering if anyone could suggest any eyepieces that would work with this scope, and aren't too hard on the wallet. I talked to someone at questar, they told me the adapter for the slip eyepieces (1.25"?) would be $80ish. I think finding one used would be hard. Someone in this post mentioned that I need to buy f/11 eyepieces. In other posts people have mentioned a 12mm is a good useful size. I have the factory 40-80 and 80-160. I think my 80-160 is 8mm? Does anyone have any suggestions in the used eyepiece in the $150 or less range. I have seen several Meade's on eBay for $50ish, and Televue for much higher.

#9 ColoHank

ColoHank

    Vanguard

  • *****
  • Posts: 2316
  • Joined: 07 Jun 2007
  • Loc: western Colorado

Posted 16 July 2014 - 12:23 AM

You mention in your original post that you have eyepieces. Are they the eyepieces that came with your Questar, or are they eyepieces you already owned? If the latter, I assume you have some experience observing. If that isn't the case, then perhaps image quality is being adversely affected by poor "seeing," usually due to turbulence in the atmosphere caused by wind currents aloft and convection currents from ground heating. If seeing is poor, those air currents will distort the view and make familiar objects like the Moon appear as if it's under flowing water. Poor seeing adversely affects all kinds and makes of scopes, and there isn't much you can do about it except to wait for better conditions.

If you have no experience with Maksutov telescopes like the Questar, you may also be unaware that, because the corrector (the front meniscus) is thicker and has more mass than the corrector or objective lens on other designs, it sometimes takes longer for such instruments to reach ambient temperature, and that internal air currents can substantially degrade image quality. When you plan to observe with the Questar, be sure to allow ample time for it to reach temperature equilibrium with its surroundings.

Finally, clean those eyepieces regardless of their pedigree. Deposits of dust and oily eye-gunk on optical surfaces aren't conducive to a good observing experience.

#10 Mike E.

Mike E.

    Vanguard

  • -----
  • Posts: 2386
  • Joined: 26 Jan 2010
  • Loc: Moonstone Observatory

Posted 16 July 2014 - 05:46 AM

Hi Paul,

I recall there is a thread here listing eyepieces which work well and also come into focus with the Questar finder, perhaps someone on the forum here can provide a link.
Both Questar & TeleVue make 1.25" eyepiece holders for your Questar. The one TeleVue makes however, does not provide a diopter adjuster to focus the finder, which the Questar unit does.
Considering the internal barlow as being 2X, your 40-80x eyepiece would be 32mm, and the 80-160x would be 16mm.
We also have an older Questar which had these eyepieces, but purchased the modern Questar eyepiece holder which allows use of standard 1.25" and threaded Questar/Brandon eyepieces.
Here is a photo of your 1 3/16" threaded, the TeleVue, and modern Questar eyepiece holders.

Note: Your 40-80x and 80-160x eyepieces can also be used in other scopes when in their holder, as it is a slip fit in a 1.25" eypiece holder.

Attached Files



#11 Matt Looby

Matt Looby

    Viking 1

  • *****
  • Posts: 943
  • Joined: 08 Jul 2003
  • Loc: Lake Champlain Valley

Posted 16 July 2014 - 09:37 AM

You should be absolutely frustrated.....that's a good thing.

First step is to realize it's not the equipment that's messed up. It is the observer. One must have a qualified mentor to teach the ropes, innumerable time at the eyepiece and a simple repeatable method....

If you want to learn to observe, PM me, we can talk via phone and if you live nearby, we can meet.

Note: Do not buy any additional equipment, you are headed swiftly down the wrong path!

Regards,

Matt
  • Larry Geary likes this

#12 Edd Weninger

Edd Weninger

    Mariner 2

  • -----
  • Posts: 208
  • Joined: 16 Feb 2014

Posted 16 July 2014 - 12:43 PM

I don’t think you need to drop a few hundred of anything to enjoy your Questar. It may be old and not have the latest coatings, but I’ll wager it is still very useable.

If you have the Questar eyepieces, you will only need a 12 mm when the scope is working well, and the sky is being co-operative with good "seeing" conditions. The 12 mm will produce higher magnification, and high magnification requires a very steady atmosphere (which is a rare occurrence). The eyepieces that came with the scope are of good quality. You don't need any others.

My Questar is the smallest scope I own, but it is an enjoyable instrument that provides much pleasure. I have several other eyepieces of good quality, but have used a 12 mm very seldom. I bought my Questar in 1989, 25 years ago.

I'd suggest you learn to observe starting with the Moon. Presently, the large planets are not located where good views are possible. Many Questars came with a solar filter that will enable you to view sunspot activity (Note: do not do this unless you are certain the finder scope ALSO has the solar filter, and you know how to use it !!).

Finding other objects, such as double stars and globular clusters, will require a knowledge of the sky and how to locate things there. Understanding how to use the setting circles will get you close, but it will still require a patient search to put the desired object in the field of view using your lowest power eyepiece. The finder is the poorest feature of the scope.

Have you used your Questar in the daytime? Mine will focus as close as 11 feet and makes a nice long-distance microscope.

edit: Use the scope without flipping the Barlow lens into place. It could be a cause of mis-alignment.

#13 peashooter1982

peashooter1982

    Lift Off

  • -----
  • Posts: 7
  • Joined: 21 Sep 2013

Posted 18 July 2014 - 08:44 PM

Good advice above regarding cooldown requirements, seeing, limitations of small aperture, etc. Is there an astronomy club in your area? Does your state sponsor a regional star party? It'd do you good to compare your Q side-by-side with someone else's. By swapping eyepieces, looking at the same objects, etc., you'd have some idea of where you stand vs a "reference" Q.

#14 Larry Geary

Larry Geary

    Surveyor 1

  • *****
  • Posts: 1831
  • Joined: 24 Sep 2006

Posted 09 August 2014 - 09:39 AM

Hi
I inherited a well used 69' 3.5 basic model some years ago. I have not been impressed with the proformance. I talked to someone at Company 7 about a cleaning. He mentioned that because of the age I might consider having it cleaned, and shelving it as an heirloom. He suggested I then buying a newer model with better tracking, optics, mirror, coatings, and eyepieces. Well *BLEEP*.
While I know this is an expensive hobby, I thought I could drop a few hundred here and there. I know my old eyepieces have some dust (not much), I was wondering if they might be the culprits. Am I expecting to much from this little, old telescope? I have seen some small refractors with ED glass and they are sharper than my scope.
Should I try updated eyepieces? With an adapter ?
The skinny is if I need any new coatings, glass, mirror etc I can't afford it. I can scrape the money for a cleaning or some eyepieces, but not both. Is there any tell tail signs that something specific might be wrong? I know these are some vague questions. Please excuse my ignorance I just want to love my telescope as much as others love theirs.

 

Hi Paul,

 

I can't tell from your post exactly what problem you are having with the Questar. But unless the scope was violently abused, there is nothing wrong with it that can't be easily fixed by Questar. I'm frankly shocked that Company 7 would suggest you shelve it and buy another one, because the differences would be almost unnoticeable. You have a scope that many people would love to be given, so don't do anything rash.

 

There is nothing wrong with the eyepieces that came with the scope. People prize them. You say the mirror looks fine, so it doesn't need re-coating. You say there are blemishes on the corrector, but those will not affect the views at all. There is the possibility that the scope has fallen out of collimation - I've seen one badly-collimated Questar that gave terrible views -  but Questar will take care of that during service. Unfortunately their standard service costs $450.

 

We don't know what your level of observing experience is, so we don't know if you are making rookie mistakes or not. But just in case:

 

  • Don't set up on a hot surface like concrete or asphalt.
  • Use a sturdy table or tripod to avoid image shake.
  • Don't observe objects over chimneys, buildings, or other sources that may be emitting heat.
  • Objects lower than 30 degrees altitude will usually be less sharp due to the atmosphere.
  • Give the scope 30 minutes to an hour to cool down after you set it outside.
  • Using the legs, or attaching the base to a tripod head, make sure the scope is polar aligned for good tracking.
  • On the control box, the upper-right knob changes from finder to main scope. Flip right for finder, left for main scope.
  • When in finder mode, rotate the eyepiece to focus.
  • The upper-left knob controls the barlow. Flip right for barlow, left for no barlow. The barlow doesn't work with the finder.
  • When switching to/from the barlow, you will have to refocus using the focus knob on the lower right.

 

In addition to not knowing your level of experience, we don't know what your expectations are. When I first got my Questar, I had high expectations from reading all the ads in Sky & Telescope, and I was disappointed. I placed an ad to sell it. A man who owned a 3" Unitron refractor answered my ad, and we met at his place to try out both scopes. We found that the Questar had better light grasp and slightly better resolution, while the Unitron refractor had better contrast. We both decided to keep our scopes, and I still have my Questar 29 years later. What I learned in the mean time was how to use it and what to expect from it. It has some great virtues, but it also has limitations. Its main advantage is portability - I can take a complete equatorially mounted scope capable of some astrophotography anywhere in the world as airline carry-on luggage. I've seen the C-ring of Saturn from the big island of Hawaii, and galaxies in the Virgo Cluster from a dark site in New Hampshire. It performs as well as possible for a 3.5" scope, but that is still a small scope. If portability isn't a concern, then an apo refractor of the same size will beat it.

 

Take Matt up on his offer of consultation and see what happens. Even if it ultimately isn't the perfect scope for you, it's a great option to have in hand for those times when it fits the bill.








Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics