Saturn March 14th

[U.K.Cowboy]

My first half decent Saturn shots of 2013 taken at 24 degrees elevation.

At first seeing looked great but as soon as I'd tweaked focus and got settled things went wobbly and although improving during steady moments it was always up and down.

Had to use 100% Gain to attain 30fps at f26 so noise was pretty horrid. 15fps took 80% gain but seeing was not good enough for that to work very well.
Thanks to winjup de-rotation of stacked images I've got a couple of fairly smooth results. The 2nd image totalled nearly 30 mins of capture each avi consisting of 2000 frames so a total of over 10,000.

DFK & Auto Dob used :

[asimov]

Hi Stuart. Great processing on these, despite the obvious problems of low alt. & average seeing. I too run at full gain to get 30 FPS but I'm not shooting at 15 FPS. That'd suck!;) I've never been scared of gain though. My last Saturn set from the 16/17th were with full gain & 1500 stacked. No WinJupos.

[Quark]

That a pretty impressive result for the alt and seeing conditions Stuart, well done. This must give you hope that you will get some steadier low alt seeing sometime through this apparition.

Regards
Trevor

[Shiraz]

really nice for 24deg Stuart - well done. regards Ray

[U.K.Cowboy]

Thanks John! Are you using y800 or yuy2? I've started using y800 again with Jupiter after using yuy2 for a while as its less noisy but am thinking I should go back to yuy2 for Saturn. Trans seems rubbish at this low alt. Only 50% histo at 100% gain. Maybe when seeing is better noise will be less.

Cheers Trevor! Yes "hope" is the key word. I've seen some very good shots lately at this alt so there is light at the end of the low alt tunnel for sure!

Thanks Ray!

[asimov]

Well I'm trying something new lately - Y800 + unspecified. Seems to be quicker to process in Autostakkert than Y800 + Y800..

Yes @ 30 FPS may as well go back to YUY2 + unspecified I feel.

On my last captures I was running at a 35% full histo (F30 +) so I'm surprised I ended up with a good result.

You could try an ADC, in fact I'd recommend it on Saturn at your alt. I must state I've been using mine even as high as 45 degrees.

[U.K.Cowboy]

Thats interesting John I've never used unspecified and did not know you could use it with y800. I shall look into the ADC if they are not too pricey. ;) Btw I've just got a mono QHY5L-ll to try out on Saturn..not planning to go RGB just mono stuff. It has same sensor as the ASI120mm that everyone is shouting about. I want to use the larger chip for Lunar and Solar stuff.

[asimov]

Well you'll be dissapointed because the ADC comes in as pretty expensive I reckon, but depends on the budget I guess.

I'm not yet convinced CMOS is the way to go. I've not seen any better results with the ASI120MM than with the 618 CCD. To it's credit I have seen images on a *par* with some of the best 618 results. A faster framerate over the 60FPS Imaging Source in a camera has me interested however..I'd love to see the QHY5L-ll results, especially on Solar.

[U.K.Cowboy]

Yeah the ADC is a bit pricey for me right now but who knows in the future I might try one.
Totally agree with you over the CMOS cams John but price being nearly half that of a DMK I thought it was well worth a try as a 2nd cam. 105fps at 640x480 will be handy for those sun spots and some lunar shots. Hope to get some good mosaics as the tracking on my Dob makes it tough when shooting 640x480 sections. Just need the freaking weather to improve lol