Help for a beginner with a 'skywatcher 200p dobsonian'

[Freeman_One]

Hey all, any suggestions.

Just got my scope come through, I also brought a premium chesire collimator which I'm pretty sure I understand how to use it. Now my problem is that during the day I set up my view finder, which was on a lamp post in the street, then i thought i'd take a sneaky peek through the main view hole, and the detail was amazing! But..

..when it can to night viewing, there was nothing to be seen through the main view, except for like a small bright donut style light disc, so I thought it must need collimating, which I've just done.The secondary mirror was ver, very slightly out, but the primary mirror seemed to be spot on, so i dont know what it can be?

The only thing i can imagine is poor collimating so i might purchase a laser collimator just for added accuracy. In the insructions it mentions cooling but surely it won't have such a dramatic effect?

Any ideas?

[yesteryeargames]

I think it could be the swivel circle bits , which are by the the eyepiece slot, they go up and down as you turn it,

try focusing on a star and it will be a donut until you focus it for each indeviual eyepiece.

,

Im no expert but it hink thats the problem ?

[MrPadz]

What does the doughnut look like? If it has lines in it which would correspond to the veins holding the secondary mirror at the front of the tube, then you're out of focus. I assume you've tried the focuser rings at the base of the eyepiece tube, so my next question is, are you using a barlow? As I understand it, some aren't always suitable for the focal length of the scope, so perhaps try using the eyepiece without. Hope you get to see something! What are you looking for?

By the way, you're better off lining your finder scope up with something more distant than a lamp post. Find a really bright star and use that (Vega, or Arcturus perhaps)

Don't assume the eyepiece to be in focus just because you have a clear image of some thing that, in a large scope like you have, is very large an close. Start on a random star.

Let us know how you get on

[knobby]

Def sounds very out of focus...

[Moonshane]

most likely is that you are using both adapters in the focuser. you only need either the 2" one or if using the eyepieces that came supplied, the 1.25" one. this is the one with the slim extension. don't put in both, it's a common error.

[Freeman_One]

hey SGL, thanks for all your help! I feel like a right numpty, I had both adapters on just like moonshane said! it's all good now Thank you loads

[Rockrae78]

We've all made newbie errors along the way! That's what I love about this forum... You don't just learn from people's expertise, but from their mistakes as well!

I've made a catalogue of errors since my astro journey began, and once or twice, been able to give advice to other newcomers when they've made the same mistakes I have!

I actually find it very reassuring that I'm not the only person to have been scratching my head in the middle of the night, trying not to swear out loud, and resisting the temptation to kick something!

[Moonshane]

I agree. just the other night I commented how lovely and dark the sky looked on almost all objects. I then realised that all the stars were actually blue/green and that I had left in my UHC filter!

[Astro Imp]

I agree. just the other night I commented how lovely and dark the sky looked on almost all objects. I then realised that all the stars were actually blue/green and that I had left in my UHC filter!

Sorry Shane but that made me really laugh out loud and nearly choke.