Help with heat wave effect

[sharkmelley]

Here's another link - look at the images at the bottom for another example of the "tube current doughnut":

http://www.astro-baby.com/collimation/astro%20babys%20collimation%20guide.htm

Mark

[John]

Just to set my mind at rest is there anything that could be wrong with the telescope or eyepiece that would cause this?

Nothing wrong with the scope / eyepiece as has been said. Poor viewing conditions can render even the finest equipment fairly impotent, even when it's fully cooled and collimated. I was having doubts about my 12" dob last night and that has delivered some fantastic images under better conditions. Funny how quickly the mind jumps to having irrational doubts on the equipment and overlooks the most obvious and frequent culprit - the seeing conditions   

[brantuk]

You'll find there are very few nights in the UK where you get crystal clear, stable and consistent observing conditions. There's always something making the seeing imperfect. That's why they put professional observatories high up in the mountains in the Andes or Hawaii, or even Tenerife. They're well above most of the weather and closer to space with least atmosphere to look through.

If you found it mostly "wobbly" with odd brief moments of crystal clarity - then that's about the best we get 90% of the time here - but you can be sure your equipment was well set up and nothing wrong with it, or yourself.

[Steve_meg]

Well that put my mind at ease

Think I may try a cooling fan mod, or just prepare a bit earlier.

Thanks for all you help