In this post, I break down what “seeing” actually means, how it’s measured (arcseconds!), and why even perfect-looking nights can ruin your images. I also share some surprising lessons I learned about how geography, altitude, and even the time of night can make or break your results. If you’ve ever been frustrated by fuzzy details or want to understand the real physics behind the “twinkle” of stars, I’d love to hear your experiences and tips.

Let’s discuss: How do you deal with seeing, and have you found any tricks that actually work?

https://www.cleardarksky.com/csk/

https://app.astrobin.com/u/GreatAttractor?i=246828#gallery

Technically speaking, in the first half of the vid the incoming wavefronts are distorted (the Fried parameter r₀ is smaller than the telescope's diameter D) and do not focus to a clean, tight Airy pattern ([1]). In the second half, r₀ is above D and we're left with just some rubber-membrane distortion (the wavefronts are tilted this way and that, but remain mostly planar), which can be corrected in software.

[1] https://en.wikipedia.org/wiki/Airy_disk