Issue with new scope

[winsor]

I bought an 8' Orion Dobsonian, when changing the focus on the scope I get an image that looks like this http://www.youtube.com/watch?v=LgFjgsOYlXY&feature=related
Do i need to collimate? or is this normal?

[Tog_]

Is your question about the movement from side to side of the entire image? If so does that happen as you adjust the focus knob?

Please try to specific. I don't really know the cause, but others might. My guess is that focuser is not mounted in line with the the light path. More detail about what you do, to make it do what it does will be very helpful.

[winsor]

actually the problem was that i didn't have the eye piece tightened enough so when I would try to adjust the focus nothing would happen, it was just an issue of the eye piece being out of focus. Thanks for the help :-)