Post Am1II6mmbC9SwWUMM4 by jdlbt@techhub.social
 (DIR) More posts by jdlbt@techhub.social
 (DIR) Post #Am1II46sY1RadyrrlI by jdlbt@techhub.social
       2024-09-15T02:55:30Z
       
       0 likes, 0 repeats
       
       Some nights the guiding is poor, some nights it is good. Tonight it is very good.With the RA and Dec curves so flat, I would say it is dead good!With a pixel scale of 1.38"/px and assuming a normal distribution, a <0.3" guiding error means that 99.7% of the time (±3𝜎) the total guiding error is less than a pixel on the main camera!#astrophotography #guiding #phd2
       
 (DIR) Post #Am1II4z7IMpTMCFBIm by stfn@fosstodon.org
       2024-09-15T07:03:16Z
       
       0 likes, 0 repeats
       
       @jdlbt that;s why I sent my mount to service it, I could never get below 4" guiding error. Sigh.
       
 (DIR) Post #Am1II5M9uhGEVf1aDY by jdlbt@techhub.social
       2024-09-15T03:48:40Z
       
       0 likes, 0 repeats
       
       For those not familiar with astrophotography, guiding, or autoguiding, is the process of controlling the movements of the telescope to keep the targets precisely at the same position in the frame over long exposures, generally multiple minutes.While the equatorial mounts used in astrophotography track the sky at the same rate as the earth rotation, this movement is not sufficiently accurate for long exposure images, especially with long focal length optics. Tracking inaccuracies can be caused by different factors, such as an imperfect alignment of the mount's axes with the Earth's  rotation axis, or mechanical imperfections in the mount.
       
 (DIR) Post #Am1II6mmbC9SwWUMM4 by jdlbt@techhub.social
       2024-09-15T03:57:50Z
       
       0 likes, 0 repeats
       
       The guiding system uses a secondary camera to capture images of stars at intervals of a few seconds while the primary camera captures long exposures. The guiding software analyses the position of stars in the images of the guiding camera. If the stars move, the guiding software sends commands for the mount to move, in an attempt to keep the stars at a fixed location.Good guiding helps with the sharpness of the images by reducing the blur associated with an imprecise tracking movement.
       
 (DIR) Post #Am1pGHeQWoZ0Y6Jlc8 by jdlbt@techhub.social
       2024-09-15T13:12:42Z
       
       0 likes, 0 repeats
       
       @stfn Guiding conditions can vary a fair amount. I was not able to get better  than 1.8" with the exact same setup earlier this week (bad seeing, target near the horizon, few guide stars available).But I agree with you, at 4" there has to be an issue with the mount. I hope the servicing fixes it!