Also, here's a view at f/30 from 20:48UT.
Reaching the end of the data from April 13, I was able to put together this 12-frame animation spanning between 19:48 - 21:26 UT, all shot at f/30 and resized 150%. I don't normally resize that much but in this case there is a very slight hint of some southern hemisphere detail seen transiting across the disk.
Also, here's a view at f/30 from 20:48UT.
I had been watching the forecasts all day. It looked like I would get a break in the clouds and possibly some *fair* seeing conditions. Nothing to get all excited about in good weather patterns but with the conditions I've been experiencing this year, this looked like a worthwhile night. Once I pointed the C9,25 at the first alignment star I was stunned at the stillness of the atmosphere and a few minutes later I was collimating with metaguide and getting a uniform crisp airy disk. Haven't seen that since late summer! Here's a preview at f/22 with Rhea in the FOV (had to enhance the moon a little bit).
You capture nothing if you don't try. I read this somewhere on CN and it was playing in my head all day yesterday while I was trying to decide if the slowly improving conditions were worth setting up the scope and capturing Saturn. The weather has been unusually bad this year with my last window being a month back! The chilly temperatures were not encouraging either! Never the less I decided that whoever said that is propably right so around 23:00 (March 11) the C9,25 was set up and cooling!
After the obligatory collimation check & touch up, I pointed the scope at Saturn and began capturing, this time experimenting with longer capture times (up to 240 seconds). I'm currently sifting through the data which seem promising but, yet again, I must pay more attention to the collimation as it is evident that we are not quite there yet.
Here's a preview of the data quality. I'm crossing my fingers hoping it will turn out good.
P.S. it's b/w because I didn't use debayering!
A reprocessing of some of the data from February 10. Slightly different color balance & 150% resizing.
Saturn 10 February 2011 - reprocessed
Below you will find the single best image from the data set of February 10 aswell as a 17-frame animation compiled from stacked images spanning 36 minutes apart. Despite the poor data quality there is a hint of the storm moving across the Saturnian atmosphere. This is the first time I've had data good enough for something like this!
The skies finally cleared and settled well enough for the C9,25 to venture out again and have another shot at Saturn. Following up on the f/issues I was experiencing I decided to test both the Ultima 2x and the GSO 2.5x with the focuser on 0-10-20mm positions accordingly (all the way in, half way and all the way out). I opened up the scope at 00:30 UTC and with the cold breeze freezing my fingers I touched up the collimation which had shifted considerably since last time. I shot avi's at 30fps for 3mins (dont ask why, I hadn't done this since the 19th of January and I was half asleep!) ending up with ~5000 frame vids which I trimmed to 600 frames with Virtual Dub as I wasn't interested in image quality but target size only.
I ran the avi's through Registax with the same parameters and measured Saturn's disc size in Photoshop averaging the result with both X and Y axis pixel count in the formula. Here are the results of the test runs:
C9,25+Ultima 2x @ 0mm = f/21,8
C9,25+Ultima 2x @ 10mm = f/22,4
C9,25+Ultima 2x @ 20mm = f/22,45 (...which is odd!)
C9,25+GSO 2.5x @ 0mm = f/21,1
C9,25+GSO 2.5x @ 0mm = f/21,7
C9,25+GSO 2.5x @ 0mm = f/21,5 (...which is even more odd!)
Conclusion? ...well it seems that the GSO 2.5x Barlow doesnt seem to add that .5x extra to the Ultima. This might mean that the Ultima is a bit more powerful or the GSO is weaker than advertised, at least in my scope. I'm not sure what happened at the 20mm position for both barlows as I wasn't swapping them between runs instead I ran the Ultima at 0-10-20mm and then the GSO in the same way. After I was done with the testing I put the Ultima back in the focuser and shot a few avi's of Saturn which I will begin to process shortly. I guess the GSO will be up for sale as I can't justify keeping it & besides, I wouldn't give up on my Ultima just yet!
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