C-90 focusing questionPosted By Bill Dellinges |
Group:
As a long time Celestron scope owner I got to thinking about the C-90 I once owned and how it focused. I recall I turned that big black ring around it but what happened inside? That is, how was the mirror moved (or not, maybe the secondary moved as you turned the ring?). Just curious.
As a long time Celestron scope owner I got to thinking about the C-90 I once owned and how it focused. I recall I turned that big black ring around it but what happened inside? That is, how was the mirror moved (or not, maybe the secondary moved as you turned the ring?). Just curious.
