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Kokatha man
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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: DesertRat]
      #5649697 - 01/29/13 04:32 AM

Thanks also Eddgie!

Quote:

Darryl I understood you did not do a RGB derotation, my question had to do with the video recordings only. Since some were claiming to see details of the hexagonal pole - I was wondering how that was possible unless the video had been derotated.

A star in focus is the best collimation tool. Its actually difficult to not overexpose an infocus star. I have the gain practically off when I do. One align point in AS!2 and stack anywhere from 5-25% of the frames depending on seeing. And in 30 seconds you can have LOTS of frames. Use zoom to see the first ring better, gamma adjust to make more visible. Make sure your capture program preserves geometry (a recent beta of FireCap had a fault) so collimation adjust does'nt send it in the wrong direction! Fits files can cause uncertainty since different programs may y-flip the image.
Glenn




Hi again Glenn!

First, the collimation routine I normally follow is Thierry Leagault's: http://legault.perso.sfr.fr/collim.html - I'm fairly certain all his image examples are stacked and quite possibly from an artificial star - but I might be wrong there!

I do find this one of the most comprehehsive/authoritive texts imho, but when I use the words "normally/usually" it's my preferred regimen if and when time & conditions allow it.....under anything but "very good" conditions I rarely see the Airy pattern onscreen visually - you're right about stacking revealing said of course - but (again imho) for me at least this is an iterative process from Fresnell Patterns/DR's through to AP's in very good conditions - and my regimen takes into account whatever is "best practice" at any particular time...

I'm quite confident of my regimen in normal circumstances Glenn, but there were so many factors impinging upon this that morning.....the mirror movement for one leading to the choice of a nearby star and its' dimness.....the rather unsteady nature of the onscreen image and clouds looming out of the West (sounds like a perfect "drama script"..! )

I was blissfully unaware of the mirror problem when I was only attempting imaging on Jupiter during the major part of its' apparition, but now with Saturn in the morning when I first took a look at collimation even though the scope had been sitting in very uniform (coolish) temperatures between midnight and around 4am, I was surprised to discover collimation had been quite markedly affected.....the only change being moving the scope from one part of the sky to another...

I will engineer 2 simple mirror-locking screws as I did on the C11 where they worked very well, assisting the primary focus screw's stabilising of the primary on its' sleeve/bearing around the primary baffle by supporting/locking the other 2 arms of the "triple-tree" assembly connected to the rear of the primary mirror assembly.

But you'll have to run your "Darryl I understood you did not do a RGB derotation, my question had to do with the video recordings only. Since some were claiming to see details of the hexagonal pole - I was wondering how that was possible unless the video had been derotated." past me again brother.

I'm at a loss to quite understand your question - I interpret it as suggesting that "unless each channel is first derotated and then combined there would be no possibility of discerning the "hexagonal" outline of the NPZ due to some application of "principles" of seeing/resolution/angular momentum etc of the relevant areas on that (smaller diameter) section of the Saturnian disk apropos the length of the recordings etc..?!?"

Apologies if I'm putting words in your mouth and am completely "off-target" with my interpretation thereof.....but to me it is quite obvious: I'm a skeptic at the best of times so I've just done a little "blind" interview with my eldest son who knows nothing about Saturn and its (roughly) hexagonal NPZ...

Looking at the image at 300% and ONLY being told that dark area at the bottom was the NPZ I asked him how he perceived it shape/outline.....without any coaxing or remotely suggestive inferences etc (you'll have to believe me on that one bro) he noted it clearly wasn't "curved/rounded" in the same manner the other bandings were and that it "sorta looked like it had sides to it." (his words)

I then gave him the spiel about the hex shape and when I dropped the size back to posted scale he agreed that it was quite reasonable to see a hexagonal outline.....he's an environmentalist who has specialised in Geophysical Information Systems mapping and interpolation/interpretation (not that saying this is anything other than that he has quite a bit of experience with Earth images and patterning!!!)

But I think my best response is to say that I believe I can see said shape quite clearly.....using very rough measurements the length of (what appear to me to be) the most obvious and "central" sides are 2 arcseconds & 1.6 arcsecs respectively, conservatively estimated and taking into account some foreshortening, well within resolution possibilities afaik...tbh I also think the second image in this other recent thread of mine (roughly) shows the said shape also, and a much inferior capture... http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Board/Imaging/Numbe...

I respect the fact that you may well disagree totally with any or all of the above, and I guess that'd be a bit like my recent discussion with Fred where I don't think there was any real agreement.....of course there's allways going to be some hype when someone posts a half-decent image but like any specific formulae for imaging trains, processes & resolution etc I'm allways going to be more cognisant of practical outcomes - with as much skepticism & objectivity as I can muster (which is why I posted the Diffraction Ring pattern so as not to appear to be "guilding the lilly" re any possible critical appraisals...)

I readily appreciate that the "powers of suggestion" are easily all-consuming.....and CN certainly ain't immune to that phenomenum but in this case whilst I know I'm waiting for new glasses I don't think either factor is playing too great a part in my own appraisals..!

At any rate I will certainly be putting this to the WinJupos team when I email the image to them tonight..!

Edited by Kokatha man (01/29/13 04:34 AM)


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Kokatha man
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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: Kokatha man]
      #5649699 - 01/29/13 04:51 AM

...ps Glenn - you're not possibly confusing the much smaller (and imo completely unresolvable) North Polar Vortex, as opposed to the (huge) hexagonal wave pattern I believe my image clearly shows which is situated around 78° N....?

Each side of this hex is around 14000km in length with the "whole shebang" rotating in 10.7 hours (roughly) - I'll let you do the maths on how that relates to resolution & rotational rate etc.


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Mitchell Duke
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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: Kokatha man]
      #5649750 - 01/29/13 06:37 AM

Wow what an amazing image Daryll!

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Kokatha man
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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: Mitchell Duke]
      #5649752 - 01/29/13 06:45 AM Attachment (62 downloads)

Thanks Mitchell - I appreciate your feedback!

Glenn - perhaps this might influence the debate a tad..?

Edit - just cleaned up (in CS4) slightly the very rough NP map I posted here .....

Edited by Kokatha man (01/29/13 08:13 AM)


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MvZ
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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: Kokatha man]
      #5649756 - 01/29/13 06:49 AM

That is soo cool. Absolutely incredible stuff...

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Mike Phillips
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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: MvZ]
      #5649982 - 01/29/13 10:18 AM

That polar projection doesn't look perfectly round to me. I can't say it's shape exactly, but it's not 100% round!

WOW!

Mike


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Rankinstudio
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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: Mike Phillips]
      #5650188 - 01/29/13 12:18 PM

I think there is no doubt you caught that hexagonal shape on the pole. Amazing stuff.

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Mert
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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: Rankinstudio]
      #5650358 - 01/29/13 01:46 PM

Amazing stuff Darryl, you've set a new standard!

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bunyon
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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: Mert]
      #5650396 - 01/29/13 01:58 PM

Another vote for non-circularity at the pole. It looks hexagonal. But, to be fair and honest, I think my mind sort of "expects" it. That is, I'm not sure it is as hexagonal as I think it is.

It is, however, clearly non-circular, which is an amazing feat. Congratulations.


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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: bunyon]
      #5650560 - 01/29/13 03:20 PM

It somewhat cracks me up how skeptical people can be on this forum. What are the odds that his stack clearly rendered 4 sides of a hexagonal shape as an artifact? I'm sorry, but my mind isn't expecting a hexagon, and it is not even close to round. There is a very clear 4 sides of a 6 sided polygon there (IMHO) and I think this will be easily proven in later imaging runs that come out on this forum later in the season.

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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: Kokatha man]
      #5650579 - 01/29/13 03:28 PM

Darryl,
I understood you had not done a derotation of RGB frames, but was wondering if you had performed a derotation of the video streams. I understand now that you did neither.

Since the time of your recordings were under 2.5 minutes per channel and the fact the polar areas don't move much in that time, I'm ok with thinking that the hexagonal structure might be resolved. I hope you and others down south can demonstrate this further. Thats just my scientific background coming through. In no way did I want to dampen your enthusiasm or take anything away from your great image.

All the images Thierry shows are computer generated. I don't know if he uses an artificial star when actually collimating. But your idea of a mirror locking mechanism is good. Then one should be able to shoot directly to Thierry's 3rd step which is to collimate with a star in focus. Its good practice to end focus with main mirror using counterclockwise movement to load the mirror, lock and then focus with the Crayford. I know you know this already but for completeness sakes, and the others reading this, I thought it good to mention.

Glenn


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bunyon
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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: Rankinstudio]
      #5650591 - 01/29/13 03:32 PM

If that is referring to me, David, I'm not trying to be negative - I plainly stated that it looks hexagonal and did not say one word about "artifact". It clearly isn't an artifact. I even called it a "feat".

As to not expecting a hexagon, before I looked closely at it, I read several posts talking about a hexagon and I've seen the Cassini images of the hexagon. It's hard to divorce that from your expectations.

Like you, I think it's real and like you I think that later in the apparition - or, if not, in the next few years as the pole becomes more and more visible - this feat will be borne out as real. It's a stunning image and a real testimony to what good tech in the hands of one skilled in the arts can do at this point. If you must know, I've even put my money where my mouth is here (if you get my drift).

However, I think we should always tend toward the skeptical with any new imaging breakthroughs (or, for that matter, any new discovery).


EDIT: Maybe you were referring to Glenn's question about derotation - I think it a good question but based on little polar movement (as Glenn says above) I doubt it plays a huge role. To clarify my position: if all I had to go on was the original image, I'm not sure I'd buy it although it certainly looks hexagonal. I think the polar projection nails it, though.

Edited by bunyon (01/29/13 03:42 PM)


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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: bunyon]
      #5650619 - 01/29/13 03:45 PM

Quote:

If that is referring to me, David, I'm not trying to be negative - I plainly stated that it looks hexagonal and did not say one word about "artifact". It clearly isn't an artifact. I even called it a "feat".

As to not expecting a hexagon, before I looked closely at it, I read several posts talking about a hexagon and I've seen the Cassini images of the hexagon. It's hard to divorce that from your expectations.

Like you, I think it's real and like you I think that later in the apparition - or, if not, in the next few years as the pole becomes more and more visible - this feat will be borne out as real. It's a stunning image and a real testimony to what good tech in the hands of one skilled in the arts can do at this point. If you must know, I've even put my money where my mouth is here (if you get my drift).

However, I think we should always tend toward the skeptical with any new imaging breakthroughs (or, for that matter, any new discovery).




Paul, it was not directed at you, there are more than a few posts that are doubtful in this thread. I have nothing wrong with skepticism, there just seems to be a very large dose of it on these forums at times. Sometimes I catch myself wondering how much of it is actually scientifically motivated... we are human after all. It got really bad on the last image of an impact on Jupiter, which was a stunning capture.

I share your sentiment, the image is a real feat. A combination of good seeing, a large scope, and a new camera with capabilities are not fully understood yet. Bravo to Darryl, the ASI120MM, and the C14.


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bunyon
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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: Rankinstudio]
      #5650632 - 01/29/13 03:50 PM

Fair enough - and certainly if the skepticism isn't scientifically based it shouldn't be there. Hey, I'd love to image the hexagon. Heck, I'd like to get a color Saturn. But that shouldn't let me doubt other's work.

As Glenn says, though, that science training makes one keep asking questions. It is almost rote at times. Questions get asked far past the point that most folks are convinced. Very, very occasionally, those extra questions uncover something interesting.

(I do recall the Jupiter impact thread. There were indeed some fairly unbelievable questions toward the end of that).


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anemec
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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: bunyon]
      #5650795 - 01/29/13 05:31 PM

Just gorgeous. Makes me think I should have gone for the ASI120MM instead of the ASI120MC.

Congratulations on a great image. Good luck with the head.


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lcd1080
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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: Kokatha man]
      #5650975 - 01/29/13 07:19 PM

Quote:

...over the next 3 months Saturn will grow a couple of arcseconds, go from 0.6 magnitude to 0.3, climb about 20 degrees higher in the sky and (hopefully) there'll be better seeing opportunities also along with me really coming to grips with image scales and settings with this great little camera.....and next time I might get time to collimate...properly


Darryl I continue to see a hexagon in your image but any doubt held onto by others should fade in the near future when the factors you cite in the above quote begin to kick in. I for one can hardly wait to see what you'll come up with in April!

Pete


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Kokatha man
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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: anemec]
      #5651059 - 01/29/13 08:02 PM

Thank you also Mert, Adam and Pete - most appreciated and I'm hoping for a good imaging season also!

Golly gee fellas, I'm the biggest skeptic you'd find in a month of Sundays!!!

As to scientific logic or any other types all this had me thinking about the a priori, axioms & Euclidean theorems.....please excuse me for digging a bit deeper by mentioning such "esoteric" philosophy/thought-processing into an AA thread..!

One definition of a priori:"A thinker’s justification or entitlement in
forming a particular belief is a priori if it is independent of the content or kind of
any of the thinker’s particular perceptual experiences."


Wiki's for axiom: "As used in modern logic, an axiom is simply a premise or starting point for reasoning.[4] Axioms define and delimit the realm of analysis; the relative truth of an axiom is taken for granted within the particular domain of analysis, and serves as a starting point for deducing and inferring other relative truths. No explicit view regarding the absolute truth of axioms is ever taken in the context of modern mathematics, as such a thing is considered to be an irrelevant and impossible contradiction in terms."

The esoteric I deliberately type as "esoteric" above - and old Euclid is also (slightly) relevant to this post....!

Tbh (and you can check the thread) I made no mention of the "Hex Storm" untill well after others had started debating said.....I didn't have one ounce of doubt mind you, but I do respect each and everyone's right to doubt, debate and even believe it isn't apparent...and still do so on this particular subject if they so wish, as a matter of fact!

I actually confirmed this shape with the red channel which I processed and loaded into WJ to create the NP map - all this before I'd even posted that red channel and before I got into my (alternative) long-winded rationale.....I wanted to be dead sure and I also wanted that confirmation via an rgb WJ compilation. (I have made said - obviously - and hopefully will post it later - although I want to "fiddle" with it a bit more yet. )

So I guess in loose terms I held "esoteric" knowledge and thus an advantage over everyone except my partner and "imaging comrade-in-arms" Patricia.....I apologise for taking my time revealing my complete hand but I do like a good debate - and you all know how I love to waffle on ad infinitum..!!!

- and old Euclid?

If we're going to be completely honest and accurate I believe we can clearly state that my image (particularly the NP projection) demonstrates a roughly polygonal outline to the (darker) NPZ with what could (fairly easily) be identified as vertices at the intersection of the (roughly) straight edges.....

The specific polygonal shape - a hexagon - is what is revealed in the infinitely more resolved Voyager images...although even at that resolution the shape could never defined as anything more than a "rough" hexagon in actuality.

Glenn - I don't contradict much if anything of what you've said on the subject of collimation (and yes, to my mind Thierry's images display a far-too-bright poisson point to be "real" imho...but that takes nothing away from the quality of that as a reference article! )

Also, you must appreciate that I'm not like most imagers in that the scope (aside and as well as from the mirror "sag" per se) is lifted and carried to my car and carried in it on a sled.....and even at my close-by dark sky site on the edge of the Murray Mallee (where I took this image) about 130km from home I travel the last 0.5 to 2km on bumpy dirt roads. (depending upon which of the 2 places I usually stop at)

I drive what you term an "SUV" or what we term a "4WD" or "Bush Basher" (Nissan Pathfinder) and the suspension is much harder than that of my old Ford station wagon...

I mention this because collimation is allways quite severely affected by the time I get anywhere and actually have the scope on the mount.....in fact I also suspect that some recent very high temperatures might've moved grease between the primary sleeve & baffle because a most surprising thing occurred whilst we were up there - I had to readjust the primary focus knob to throw the image sufficiently far out from the Moonlite to get it within the movement's range.....this could only indicate serious "sag" to me even though I do "load" the mirror with cc rotation of said knob...

I'm sure I'll rectify the problem but a complete fix will have to wait untill after this Saturn apparition.....I can counter the problem with my normal/usual obsessive collimation regimen but I want to dis-assemble the scope for a complete flocking job also - another aspect that folks have divergent views on but imo my work on the C11 with that made an enormous improvement to contrast enhancement...and I'll "kill two birds with one stone!"

Anyway, enough for now and I'll post the WinJupos combination later - not sure if it'll be an improvement but it will be slightly different..!


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wenjha
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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: Kokatha man]
      #5651068 - 01/29/13 08:07 PM

Wow!that's interesting! congratulations to Darryl's new discovery!I would like to getup early and try saturn!

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DesertRat
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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: Kokatha man]
      #5651096 - 01/29/13 08:24 PM

Darryl,

Appreciate the "bush basher" mode of scope travel will add to some collimation issues. Been there, done that, we have plenty of bumpy dirt roads here as well! My old C11 was a collimation nightmare - you could here the mirror flop on that guy on meridian flips!

Look forward to your workng this data set. Any possibility of an animation of the n polar map? Not that I want to create more work for you, and I hope your head is better!

Lastly congratulations on an amazing early Saturn!

Glenn


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Re: Saturn + ASI120MM ÷ Goodish Seeing=Lotsa Detail!!! new [Re: DesertRat]
      #5651174 - 01/29/13 09:13 PM Attachment (117 downloads)

Hi all,

I don't know if this helps the discussion or is totally not useful, but I found a Cassini image of the hexagonal north pole storm and resized it to Darryl's image (side by side) for comparison. One caveat is the Cassini image was shot in IR. Also the tilt of the planet is different, but I don't know how to deal with that in PS or whatever. This is quite an interesting discussion and I'm enjoying all the ideas and thoughts.

Paul


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