Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Stargazing Bought Orion AstroView 90mm, good?

  1. Sep 12, 2012 #1
  2. jcsd
  3. Sep 12, 2012 #2

    turbo

    User Avatar
    Gold Member

    Re: Planning to buy a first telescope?

    90 mm is OK if the optics are good. My finder scope is 90 mm and my main scope is 150 mm. I'll take the 90 mm Vernonscope out on the deck from time to time. In these dark skies, you can pick up a lot of faint objects with 90 mm.

    I should mention that the mount illustrated in the ad is very light. If the wind is very light or non-existent, you can probably squeak by, but you might have to stiffen that mount somehow. Good luck.
     
  4. Sep 12, 2012 #3
    Re: Planning to buy a first telescope?

    Thanks I appreciate the advice! What would you suggest I do to stiffen up the legs? Do you think velcro ankle weights would do the trick?
     
  5. Sep 14, 2012 #4

    russ_watters

    User Avatar

    Staff: Mentor

    Re: Planning to buy a first telescope?

    For a first scope that's a good choice. My first was the standard 60mm x 900mm. With your larger lens, you'll get brighter and higher resolution images. Manual equatorial is also a good choice, but make sure you really put in the effort required to learn to use it properly. It makes observing a lot easier and you'll also learn about the sky more.

    Regarding stiffening the legs, I don't consider that a priority. Yes, it may help but you've got a lot of other fish to fry before that becomes a significant issue for you. Heck, my rig weighs 150 lb and I still find the best way to keep it steady is simply not to touch it when looking through it.
     
  6. Sep 15, 2012 #5

    chemisttree

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Re: Planning to buy a first telescope?

    Turbo is right about the mount being very light for that scope. My son's C4 (Celestron 102mm f9.4) refractor sits on a CG-4 very stably. That is likely the best inexpensive mount for your scope. You can modify the legs of your CG-2 as was described here if you want to try that first. It is a great modification to replace those aluminum legs with wooden ones and it requires very little in the way of tools. (drill, sandpaper, rasp or jigsaw, adjustable wrenches) It's not necessary to replace the round stainless steel legs that come with the new CG-4 mount.

    You may find that the view bounces around in a light breeze and blame the legs for that. What I have found with lightweight mounts and long tube scopes is that the backlash on the RA is the biggest culprit and that can't be addressed by stiffening the legs. You can help it a bit by tightening the mesh on the pinion/RA gear and eliminating as much as possible the pinion axis play (thrust-type play). Diagnose the play by placing your fingers on the pinion axis and slightly tap the OTA. You will definitely feel the play.

    90 mm is a pretty nice apeture for grab and go and the 1000mm focal length is the sweet spot for pretty good magnification and moderately wide field. You should be able to have great lunar and planetary views as well as globular clusters and double stars. With wide angle eyepieces like the Meade SWA 28 or 34mm (used) you will have fantastic views of globulars, larger nebula like M-42 and most of the open clusters like the Pleiades or the Double Cluster. You might find that there is a little purple color at high magnification for bright objects but that can largely be eliminated with a minus violet filter or the Baader Contrast Booster which is also a fine Mars filter.
     
    Last edited: Sep 15, 2012
  7. Sep 25, 2012 #6
    Re: Planning to buy a first telescope?

    Thanks for all the great advice everyone! I have gotten pretty good at finding stuff with the telescope. So far I have seen Jupiter, Io, Europa, Ganymede, Callisto, Pleiades, Luna (can't wait for the harvest moon), Vega, Deneb, Altair, Aldebaran, Polaris (obviously), and a few others I don't know the names of yet.
    I just ordered a 3x Barlow and a Nebula Filter from Orion. I'm hoping that these will allow me to see Andromeda Galaxy. Does anyone have any advice for spotting Andromeda Galaxy? Also I believe I can see some smudges on the screen of the star diagonal. Anyone have any tips on cleaning that bit? Also could ya'll give me some advice on which one of these Orthoscopics is better?
    http://agenaastro.com/kokusai-kohki-japanese-orthoscopic-eyepiece-7mm.html
    http://www.teleskop-express.de/shop/product_info.php/language/en/info/p624_Orthoskopisches-Okular-7mm-Brennweite---1-25----Kasai.html
    All your advice is appreciated!

    -Jack
     
  8. Sep 27, 2012 #7

    chemisttree

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Re: Planning to buy a first telescope?

    The Andromeda Galaxy is huge. Much larger than the full moon but the outer edges are probably going to be difficult to see. You don't need any magnification to see it at all. The best view with your scope will be at 25 mm to 35 mm with as wide a field of view as you can get. The nebula filter won't work on the Andromeda Galaxy but it will work on planetary nebula like M27 or emission nebula like M42 in Orion. You really don't need one IMO.
     
  9. Sep 27, 2012 #8

    Chronos

    User Avatar
    Science Advisor
    Gold Member

    Re: Planning to buy a first telescope?

    I agree, aside from perhaps a moon filter, they are a waste of money for the vast majority of amateurs. The money is better spent on accessories like dielectric diagonals.
     
  10. Sep 28, 2012 #9

    Drakkith

    User Avatar

    Staff: Mentor

    Re: Planning to buy a first telescope?

    Hmm. I need a spectrograph!
     
  11. Sep 28, 2012 #10

    davenn

    User Avatar
    Science Advisor
    Gold Member

    Re: Planning to buy a first telescope?

    as chemisttree commented ... Andromeda galaxy is huge
    you need a dark sky site ... that really helps. its easily visible naked eye
    using a star map of the Pegasus and Andromeda constellations area you will easily find it doing some star hopping. I suggest using even low power binoculars say 7 x 50 before using the telescope

    Once you find that, then you can move a bit into the Triangulum constellation
    and have a look at M33 another large spiral galaxy. This one is face on to us and has
    quite a low surface brightness but again a dark site and binoculars should be enough
    to initially pick it out

    cheers
    Dave
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Bought Orion AstroView 90mm, good?
  1. Orion Solar Filter (Replies: 3)

  2. The Orion Trapezium (Replies: 1)

Loading...