Re : running relaxed, it is said that the real marathon is the training you put in, and the race itself should feel like a celebration. I am not anywhere near elite level but felt that for a lot of races. The hardships of the training enables a state of deep calm, joy and feeling like you are flying the morning of the actual race. Nights before races are often very bad, like a last storm before everything clears and your mind is finally empty when you get into the corral. Then, with a clear mind, you proceed to run with joy despite being physically tired by the training and sleepless night.

Hi, I could send you the link but as outlined in the post, this specific mirror was very out of tolerance..

I looked but AliExpress makes it impossible to locate even specific sellers, like BohrOptics, who I found to have consistently good quality (bought a beam splitter and fused silica ball lenses from them).

This article gives great impressions of what you can see with your eyes through various sizes of telescopes : https://www.deepskywatch.com/Articles/what-can-i-see-through...

This one is a bit of a joke with my telescope making friends, but ticks all the boxes of what I consider a real telescope. You can actually buy 76mm entry-level telescopes, but they often have an unstable mount and bad optics. Starting at 150mm, you already have a lot of punch under dark skies. Visual use, live digitally enhanced, or astrophotography are 3 different hobbies.

Small mirrors with a very low F-ratio are also something that you need to grind yourself. I have a 6" f/2.8 telescope and a 8" f/3.5 hyperbolic + ross telescope, and both aren't commercially available while being small mirrors !

Progress on my 16" f/3.2 is currently stalled though.. a multi-year project indeed.

Absolutely, second hand is the most direct path to getting a telescope.

Thanks, it's heartwarming. It's my current longest living attempt at a blog

This is the first time I've seen a build of the ABSDBS in the wild, thanks for sharing ! Sadly an 8" f/4 mirror has a very narrow range of acceptable optical quality :/. It's too bad you ended up with a bad one. Maybe refiguring it would be a great followup project though

If you want to commit to a build, this one is thought to be user-friendly and a great first instrument : https://www.printables.com/model/1325533-smallest-telescope-...

Thank you! Will check it out!

I will correct the article, I've found great λ/6 or better spheres on Ali, but have yet to get a well corrected mirror. But starting from a λ/6 sphere instead of a flat glass blank saves so much time !

For this specific mirror, I was a bit disappointed, because it was specifcally advertised as parabolic, which made this project suitable, because coating costs trump all other costs for very small builds. Well it was 1.7x too much parabolic, and now I have to pay a coating :)