More solar - 31st July

asimov (John) · #1 31-07-2011, 11:24 AM

Hmmmmm well I'm starting to enjoy this kind of imaging. Latest trend is capture at 10:15 AM as the seeing seems to be not too bad at that hour.

Just experimenting so far with camera settings. I'm using zero gain/19 gamma. 60FPS & a very fast exposure. I've read that these sunspot regions change quickly so I'm only capturing 30 sec. AVI's & stacking the best of 400.

Shooting @ 60FPS with the Imaging Source DMK, I'm getting the known artifact common with shooting at this frame rate but I've noticed it only happens on the limb. Stay clear of the limb or put up with the artifact. The other alternative would be to go 30FPS on the limb.

Cheers for looking.

C11/thousand oaks 2+/DMK/Mogg FR.

Dennis · #2 31-07-2011, 11:55 AM

A nice set there John. Isn’t it grand to have a few biggies on the sun’s disc for a change! Do you notice an improvement in image quality as the C11 reached ambient?

I’ve just come inside with a batch of avi’s of the same sun spots which I hope to process later today. I found the seeing quite variable with only fleeting moments of clarity, otherwise a lot of high frequency jitter.

Cheers

Dennis

asimov (John) · #3 31-07-2011, 12:15 PM

Hey Dennis. Long time no see/hear mate..

I've actually found the opposite to be true (yet to confirm). I start shooting the moment I drag the OTA out of the still chilly shed, & pop it on the mount.

As time passes, I start to get tube currents. I'm using the CF model, which I think helps somewhat in this case.

It's a very interesting topic, this ambient temps etc. especially with this imaging in broad daylight. My C11 was a sunlight virgin only 3 days ago!

Thanks for the positive comments, & look forward to your images later!

Matt Wastell (Matt) · #4 31-07-2011, 01:55 PM

Hi John

Nice to aee these big spots in WL - quite impressive!

Dennis · #5 31-07-2011, 06:29 PM

Hi John

I noticed from the jet stream map that Brisbane was on the edge of the nastier stuff, whereas Bundaberg was right in the thick of it.

I used every trick in the book in an attempt to tame the seeing, but it really wasn’t worth the CPU cycles and crunching of AVI’s through AVIStack.

In the end, I eyeballed the live screen and started recording in the better moments whilst pausing in the really wobbly moments. I kept this up until I had collected 1250 frames. I then harvested the best 94 frames and came up with the attached result. It’s a bit thin and although there is evidence of granulation, the detail has been punished by the high frequency jitters.

Mewlon 180 F12 at prime focus with DMK31AF04.

Cheers

Dennis

asimov (John) · #6 31-07-2011, 06:46 PM

Well I think you have a better result there Dennis than my above 3 examples. Well done! I've been in the thick of it for months & can't seem to cop a break.

asimov (John) · #7 31-07-2011, 06:59 PM

Speaking of crap seeing - I just had a look outside. You'd swear it was good seeing, but if you look real hard the jetstream is moving that quickly it's almost undetectable. Geez..

mexhunter (César) · #8 31-07-2011, 08:32 PM

Hi John:
Very nice work.
Greetings
César