Web Collimation Using Artificial Star

Folks, I just finished collimating my observatory mounted C11 using a bright LED flashlight and nominal 150um pinhole approx 100feet away. While people claim they collimate during the day, I tried this last weekend without success. Prior to this session, I removed the plastic washer under the 10:30 collimation screw attempting to "pull" the donut in tighter to this area to improve the symmetry. This did seem to help somewhat, or at least it allowed the 6:00 & 1:30 knobs to finally be tighter. I initially adjusted the collimation using the eyepiece then switched to the web cam going from f10 to f25, then f45. Finally I came back to f25 to recheck. While I was able to image a slight airy pattern at f45, I may need to revisit this fine tuning since I couldn't resist the urge to slightly tweak on the recheck. f45 (2.5x stacked with a 2.0x barlow) was very unstable even for an artificial star. While last night was cloudy I did not expect this level of turbulence. Unfortuneately with a cloudy sky I couldn't actually prove my success on a real planet.

My collimation adventures continue...
Regards,
Steve

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Steve, was your scope allowed the "required" time to cool down?
That turbulence could be due to heat plumes inside the scope, or maybe due to heat waves coming up from the ground in between you & your artificial star...


Good luck with your Collimation Adventure, and Happy Holidays! 8)