[chantepierre]

It's not about price, but enjoying the process, or making instruments that just are not commercially available. Amateurs are constantly pushing the limits of optical designs.

Here is a recent groundbreaking example from Rik Ter Horst, a 10" f/20 kutter with toroidal secondary : https://www.cloudynights.com/topic/935825-a-250-mm-f20-kutte...

I did not do anything that impressive but enjoy my own set of non-standard scopes :

- A 8" f/3.5 hyperbolic primary + ross corrector

- a 6" f/2.8 with permanently mounted 4-element corrector

and am working on a 16.5" f/3.3 that will have a permanent Paracorr II lens group.

The only messy moment was my first mirror when I learned to cut pitch, but grit and glass dust itself are no problem thanks to the wet process.

You are right though on the last bits of figuring, it's a psychological challenge and my first mirror took 3 attempts over 18 months.