I always saw those concrete form tubes at home depot, and wondered if you could make a telescope from them... And the website seems to answer that question :)

I always saw those concrete form tubes at home depot, and wondered if you could make a telescope from them... And the website seems to answer that question :) https://stellafane.org/tm/dob/ota/tube.html https://stellafane.org/tm/dob/ota/tube.html (that said, there's a LOT more to it...)