videos showing thermal effects

[bird (Anthony Wesley)]

I thought this might go in its own thread so everyone who's interested in this stuff will see it.

I've made a page that shows the dramatic difference that proper cooling on a 10" newtonian can make. The page is here:

http://www.acquerra.com.au/astro/cooling/ballarat/

Apologies for the videos being 3Mb in size, but I needed to use a codec that preserved as much of the video quality as I could.

As you can see the difference is not subtle.

Comments welcome.

Bird

[Robert_T]

This is very interesting! I think Mike commented elsewhere that perhaps a lot of what would be generally regarded and poor seeing might well be due these effects of thermal imbalance. I suspect that I've under-estimated the coolodown time for the full thickness mirror in the Mewlon and perhaps started imaging a half hour too early in some cases- mind you, of late it's been a case of snapping away whenever the sky appears because minutes later it will be gone. Thin mirrors of course have their own issues, but I guess they'd have some advantages in this regard...

cheers,

[bird (Anthony Wesley)]

Everyones scope and local conditions are unique - I guess the real message is to know your conditions and your scope so you know when it's going to be giving the best images!

Bird

[davidpretorius]

thank bird!