SCT time to ambient

[rthorntn (Richard)]

Hi all,

How long should a 10" sct take to cool properly outside and how would the fact that it was still cooling manifest itself, when checking out Jupiter this morning, the planet was shuddering slightly, I only had the scope outside for an hour tops...

Cheers
richard

[marki]

SCT scopes take a very long time to cool and are always behind the eight ball as the temp drops due to their mass. I will always allow at least 2 - 3 hours with the cooling fan running before I would bother trying to observe planets in detail or collimate the scope. I have a 10" meade lx200R.


Mark

[rthorntn (Richard)]

Thanks Mark, I don't think my older meade 10" has a fan...

[multiweb (Marc)]

Originally Posted by rthorntn

Thanks Mark, I don't think my older meade 10" has a fan...

Did a mod on my C11 with two fans a while ago blowing air in. I sometime image with them on as well. It helps a lot. I also changed the tube to a CF tube and found it helped with focus. Also doesn't get as cool as the alu tube and keeps relatively close to ambient opposed to going sub zero exposed to the clear night sky.