collimation help

I replaced the collimation screws with thumbscrews on my lx200 10". I have been working with it slowly from night to night and have came to the point where I am getting good views but not quite an airy disk on a star. but when I look at the unfocused star I see something that I didn't see before I replace the screws.
The thing I noticed was a flare through the unfocused star, its starts in the middle, the small center dot kinda flares through the star image in one direction. the center dot can not be seen when unfocused in the other direction, just a dark center. So whats going on? I'm I getting close?
One thing that is hindering me is air currents. I have not yet had the chance to stay out super late when the currents are at there least so I have been doing this through the early to late evenings

Hi, I have a 12" LX200 and it takes it a couple of hours before I don't see an upward spike in my focused or defocused star images. It might be a current of rising air off the primary mirror, collecting in the top of the tube and refracting the incoming light rays enough to show up as a spike when viewing focused or defocused star images. BTW when I collimate my scope, I do it with the star image in focus. It seems to be much more accurate than trying to center the defocused diffraction rings over the central dark disc of the defocused pattern. I just try to center the airy disc in the surrounding flare (this is done at 200x or above with my scope) and it works very well. I use this same tecnique with my 152ED refractor.

Hope this helps

Clear skies

Jeff Quinn

One idea for ya, a false star can sometimes help, if you can find one of those shiny deals on top a phone pole, or put a shiny ball bearing 5O yards away you can check it in the day time also. I don't know if this will help in your situation, I did this to check my newt and it worked great, if you can have only grass etc in between you and the false star all the better. Then you will only be looking through 15O feet of air instead of thousands of feet, and the air is more stable in the morning. Just a thought! Ron