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Saturn, Dione, Rhea & Tethys with Storm Head...


Kokatha man

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Hi all - we were out again at our favourite spot in a reserve adjacent to a tiny little village in the Murray Mallee the night before last.....there was a live band playing at the school social about 1km away and the sound carried through the still air very well: they weren't bad and kept up till around midnight which was when we packed it in also - a nice accompaniment for us to listen and "rock along" with as we plied our imaging capers on The Ringed One..!:eek::icon_salut:

Talking about "still air" it was pretty reasonable seeing.....we'd set up by 6pm under complete cloud cover, but our renewed faith (well, sort of!) in SkippySky had us semi-confident we'd get some clear sky.....and by 8pm the southern horizon was starting to lift.....within 30 minutes the entire sky was clear and pretty steady..!:BangHead:

We took basket loads of avi's but I was using the constant good seeing to do a lot of experimentation as the Orion Optics (UK) scope's arrival comes nearer: using various extensions and barlows for image scale variation between f25 & f35 alongside different histogram values.....as well as doing a few avi's where I binned all channels to raise framerates and lower gain settings: I wanted to see what this would ellicit versus the other variations we used, and put the 3x t/v barlow in plus an extension to get a relatively decent image scale whilst using 2x2 binning.....not as large as f25 scale without binning but I'd suspect around f18, hopefully suffficient to be able to upsample the end-image for a relatively appropriate comparison with (say) the f25's.....I'll do the image scale/focal length calcs on the images later to get a more accurate figure for these binned jobs: unfortunately I still find that FireCaptures logs are inconsistent in this regard. (I did mention this to Torsten once before but I'll contact him again to have a chat - FireCapture1.2 is a really marvellous program imho!:))

But this first image here is NOT the binned sample.....just the C11 @ f25.....first cab off the rank and I realised later that there were 4 moons in the original image with Enceladus cropped out of the ninox'd files - I'll repro later and include it too..!:(

On another note I got into a bit of hot water with an old friend when I challenged his assertion that the Storm Head had changed considerably over the last few weeks since my image on 27/28th April .....I think we've patched up any feelings I was making something personal out of it (which I wasn't!) but I do think this image confirms my thoughts that the stormm head is still well-defined and "active."

Hopefully plenty more comparisons to come out of this night (including the image with Enceladus, Dione, Rhea & Tethys all there plus the binned experiments.....but here's that first processed set of files.....:(

post-16205-133877568294_thumb.jpg

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.....just did an edit and changed the date in the image above: it should have read "22nd April"....!:)

Here is the very next avi processed (still with Enceladus cropped out) which I thought might have been slightly better.....but really "6 of 1, half a dozen of the other".....:eek:

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Hi Piotr - I'm not sure if I agree about the storm head diminishing.....that's what got me into hot water with Trevor, but I think these images clearly show it's raging still.....perhaps I'd agree that it most probably takes this better seeing to bring it out more nowadays.....but very prominent in red & green channels still.:)

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Thanks Karlo - here's a binned 2x2 from later in the night where the seeing might've dipped a bit.....I used about f35+ (I'll calculate it later...:eek:) to get a decent-scaled image with the binning, which halves the onscreen image and scale captured by binning.....perhaps the seeing didn't help at that particular time of the night but I wanted to see what the increased framerate and lowered gain might do with 5000+ frames in each channel.....not a lot as it turned out, but that could've been the drop in seeing....!:icon_salut::):BangHead:

post-16205-133877568385_thumb.jpg

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Thanks to everyone for their kind comments - I believe at 62 we might've pushed things a bit by imaging on Friday & Saturday nights, because last night we were set up and waiting for the air to steady.....by about 10.30pm it looked very good "upstairs" but we had to admit we were too darn plurry tired to image.....a pity - it looked so enticing....!:):o

And it was most probably the fact that after getting home on Friday night/Saturday morning (it's about a 2 hour drive to the Murray Mallee site) I stayed up till 5am getting all the files across to my home pc and doing all the preliminary vdubbing & ninox'ing.....wish I could sort out bulk-batch processing of this time-consuming stage..!:)

I'm hoping to do some more processing as Freddy intimates, including the repro's with Enceladus also.....but I needs some sleep..!:eek::eek:

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ps: J/holic, the moons will hardly ever appear obvious onscreen with the exception of Titan when it's near to Saturn (it is often way out beyond the sensor area otherwise) because, as you say, the difering exposures needed viv a vis Saturn.....

But if they're around they will be captured - but very faintly recorded.....if you know (from an ephemeris) that they're around you can try raising levels in processing (p/shop) and you'll see them.....after returning levels to "normal" surprisingly you'll most likely see them once you know where they are on the screen (tilting the screen helps here a bit also) so then it's a matter of using "shift+left mouse click" with the elliptical marquee tool to creat tightish circles around each/any moons to select those areas and then raise levels values for them, leaving the planet how you've already achieved.....

A bit of playing around is necessary here, and I also omitted to say I first use the magnifying tool to blow the image up considerably when doing the above - it helps immensely!

I also do this followed by an "auto black & white" for these moons before any final image scale reduction overall and despeckling, curves etc because thse final adjustments help sharpen and tighten the moons as more the points of light they should appear as.....quite exacting especially if you also use a magnitude guide to get each individual moon's levels correctly adjusted to display each's relative brightness.....but these finer points are things I'll do in my process "plays" over the next week or so, as Freddy suggests....!:):eek::)

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