Looks like rain...?

[Marstiphal]

Hi All,

I'm just wondering if someone could clear up for me what I am looking at (this is prob a n00b question) I was last night collimating my scope, after having many many issues with getting a clear image (that will teach me for getting a scope out my league). I pointed at a bright star, put in a lens and took the image way out of focus. Looking through to see if the star was still circular I noticed what I can only describe as looking at a window with water running over it. Any idea what this is? Am I looking at thermals in my tube?

Many thanks

[Beyond_Vision]

Yes if this was shortly after taking the scope out. Depending on it's size the scope will need to cool down for an hour or more.

Regards

Kevin

[yeti monster]

Scope details please, the more we know the better, that just means we're nosey!

Seriously, what make, model, size etc. scope do you have.

How were you collimating?

[John]

I agree with Kevin, that sounds like currents of air eddying around in your tube. Give the scope more time to cool, with the tube cap removed so that the warm air can escape. My 10" newtonian is usable after around 30 minutes but needs 60 mins to cool properly.

[Chris H]

Hi All,

I pointed at a bright star, put in a lens and took the image way out of focus. Looking through to see if the star was still circular I noticed what I can only describe as looking at a window with water running over it. Any idea what this is? Am I looking at thermals in my tube?

Many thanks

You don't need to take the image way out of focus to see if your scope is collimated, just a little out of focus and a little in focus will do.

But yes it sounds like your scope had not cooled down.