tube currents

When looking at an object defocused is it the fast currents that indicate tube currents or slow ones?? I can't remember which was atmosphere and which was tube..

Thanks

Mark V

Mark,

I'm not an expert, but the slow, unorganized looking ones are the tube currents. Before I switch on my fans, I put an ep in and defocus so I can see the currents and then switch the fans on and watch the slow ones turn into fast ones and then disappear. Maybe it's my military background, but I like the feeling of crushing the tube currents into submition. I often imagine I can hear the lamentations of their women as I vanquish them to thermodynamic haydes.

Sorry, lost control for a moment

Clear skies,

Tom

What I do is blow across the top of the OTA, if the defocused image starts rotating, then I figure its currents.

jon