Help with Orion Skyquest XT10g Dobsonian - Magnification Issues

[Petama20 (Mandy)]

Hello,

I am fairly new to astronomy and my first telescope was a Celestron Goto 80mm (never got the Goto mastered unforunately) but I have now upgraded to an Orion Skyquest XT10g...I know I know...big jump. I am very much a leaner and only know some basics and still trying to understand all the lingo and terminology but I am hoping someone could provide me with help on this telescope in relation to maginifcation. I am sure it is probably just something very simple.

I finally got the telescope out last week (August 2013) and had Saturn in my view finder using a the 25mm Deep Sky eye piece but Saturn was was really really small. I could hardly see the rings and it appeared to be smaller than viewing in my old 80mm. I expected to be able to see Saturn quite large through the eye peice so obviously my problem is maginifcation and probably using the wrong eyepiece. Could someone please tell me what I am doing wrong here. I know from reading and searching on Google that you can see deep sky objects bigger than this with this telescope.

I did also have problems doing the 2 star alignment but I am sure this will get better with practice. I hope.

I am wanting to join a local club also so they can help me in person but they are very hard to get hold of in my area (Bendigo, VIC) so I decided to join this forum.

Would appreciate any help anyone can give me on this.

Amanda

[Pinwheel (Doug)]

The trouble here is deep space objects are a whole lot bigger than Saturn, Even in my telescope Orion M-42 is larger than Saturn even though M-42 is light years away.

[Allan]

Hi Amanda,

You've got yourself a very nice telescope there. Be prepared for some amazing views.

I bought my XT12g after a few years without a telescope, and realised I had to be patient with it. Like any new piece of equipment it takes a while to get used to using it. Along the way I have improved mine with some upgraded bits.

The included eyepieces don't offer a lot of versatility. I think the standard eyepiece is the 28mm which only gives you 42X, so Saturn is going to look tiny with that. It has nothing to do with your 10" mirror what size Saturn appears. The mirror will dictate how much light is collected, and then the eyepiece is going to provide you the magnification. Have you tried viewing with the 12.5mm eyepiece. At 96X Saturn will look bigger.

One of your first extra purchases will probably be some eyepieces and a barlow or powermate, which will make your telescope much more versatile. The 28mm is fine for low power, wide field of view, but you will need some better eyepieces at the mid and short focal length. There's plenty of info and advice here for that in the eyepiece section. Don't worry about the 2 star alignment, you'll be doing that with your eyes closed before you know it.

I've got lots of info about the XTg and accessories and eyepieces if you are interested, just let me know.

[noeyedeer (Matt)]

hi Amanda,

the longer focal length of your new telescope means that your older one would've had less maginification using the same eyepiece? (sorry edited after working out focal lengths)

Allan has given some good advice, using shorter EP, and perhaps investing in a barlow. I don't think losing contrast by using a barlow on such bright objects matters that much. In fact I think they bring more out detail by cutting down the light.

matt

ps Saturn at around 200x (either a 6mm or the 12.5 barlowed is pleasant to look at)

[absolut (Rob)]

Hi Amanda!

Congratulations on your new acquisition!
I bought the same scope recently as well.

The information provided so far is perfection and Allan is proving to be the master of the Orion XTg scopes!

I bought the Orion 6mm Planetary for admiring our friends in the solar system! The only thing I've found is the scope collects alot of light and I found Saturn to be very bright, to the point of missing detail. I haven't had a chance to use some filters, but I'm hoping they will improve the experience.

On the subject of magnification, it is possible to get some extreme magnification going, the problem you'll run into going beyond 200x is you end up making atmospheric instability more obvious/distracting.

If you want to figure out the magification you'll get with any given eyepiece - take your focal length (1200mm) and divide it by the eye piece. For a 6mm eye piece: 1200/6 = 200 power.

Along with the fellow IIS peoples, I recommend you do some browsing in the eye piece section of these forums and bask in the wisdoms on offer!
Clear skies!