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View Full Version here: : Saturn + Tethys, 11/01/2006


iceman
12-01-2006, 07:36 AM
Hi guys.

Here's my Saturn image from yesterday, finally got around to finishing the processing.

Quite happy with this image:
- Cassini Division all the way around
- Crepe Ring clearly visible
- Nice banding on the globe
- A "warmer" colour tone
- And a Moon (Tethys)! Which I found hidden away.. I used NASA's solar system simulator to get the P/D data, and it also has moon positions.. I saw it had a moon close to the planet so I went back to photoshop and stretched the levels in that area, and whallah, out came Tethys. Enceladus should've also been captured but I didn't know at the time and cropped it off during my ppmcentre processing.. nevermind :)

The image was taken at 5fps because the seeing was very good at 7/10. Transparency was also better than normal, so I could have a lower gain for less grain, but I bumped up the gamma to 50% and used the brightness slider as well to give a value of 200 or so in the brightness meter. It looks a bit overexposed in the raw frames but after stacking and wavelets it comes out perfect.

I found that some of my other avi's of Saturn in the same night, where I had a lower brightness value, had the dreaded onion ring after wavelets processing. So i'm convinced that the onion ring effect is caused by underexposure.

The higher gamma value also helps bring out some better colour, and also the crepe ring. Saturation was at 100%.

For those interested, here is my processing workflow for this image..

I captured for 5 minutes at 5fps, giving me 1500 frames to start with.
I used virtualdub to split the avi into bmp's, and then used ppmcentre to rank the frames and crop them to 400x400. I used windows explorer to simply delete the worst 400 frames straight way.
I dragged the remaining 1100 frames into registax, went through the normal processes, but in the wavelets tab I used the histogram tab to reduce the blue weight to 90% and the green weight to 85%. I also moved the blue slider to the left a bit.
I took it to AstraImage, where I split into separate RGB, did LR deconvolution (5/2), recombined. I then adjusted Hue (down) and Saturation (up), and adjusted the colour balance to give it a little more red and less blue. I finished with a Median 5x5 filter to smooth it out.
I took it to Photoshop where I adjusted the levels to set the reduce the red from the background, and stretched the area over Tethys to bring it out.
That's about it :)

Anyway, comments welcome. It turned out to be a very productive morning. Seeing is king!

Robert_T
12-01-2006, 07:45 AM
Absolutely beautiful Mike - congrats! :thumbsup: Lovely banding on the globe and Tethys! what a bonus. Must find out how you do curves on just a portion of the image, I think my software can only apply across the whole image.

Re the high brightness for saturn, I've found that too that getting it up to around 200 on the brightness meter works well which is odd cos doing that for Mars would totally over expose the planet.
great stuff

davidpretorius
12-01-2006, 07:51 AM
i am going to do a side by side with birds to see which is the best so far, but regardless of that outcome, this is an excellent image

congratulations.

what is the crepe ring?

iceman
12-01-2006, 08:00 AM
Thanks Robert! To stretch just part of an image, in photoshop I just select that area using one of the selection tools, and then do new layer->curves, and adjust to taste. It creates a new layer with the brightness stretched just in that area.

and you're right about the brightness - for Mars I found best results were down under 150. It just goes to show that each planet requires her own special attention :)

Thanks Dave, but Bird's image is still far better than mine.

The crepe ring is the "innermost" ring, it's very faint and delicate, hard to capture and hard to keep during processing (aggressive processing can sometimes remove it).
See attached image with arrows.

davidpretorius
12-01-2006, 08:40 AM
ok, birds is still the best, but not "far better", i have compared. How nice is this situation, having to view these saturns and compare....heaven!!!!

so you guys can be in heaven too, here is what i was looking at

Iceman's on top, birds three underneath.

Thanks for the great images ice and bird!

asimov
12-01-2006, 10:43 AM
OMG what a great Saturn!!!!!!! Well done mate! You must be ever so happy with that!!?

Congrats!

ving
12-01-2006, 12:20 PM
i dont know mike, he has better ring structure than you but the globe colour and banding is better in your i think.
you did a brilliant jobe there mike :)

davidpretorius
12-01-2006, 12:24 PM
it is like comparing blonde and brunette miss universe competitors. you would kick neither out of bed!!!

these images are the yard sticks!!!

Dennis
12-01-2006, 01:27 PM
What a superb image Mike - well done. I was drained and exhausted after reading your processing odyssey - wow, truly a labour of love! It was well worth the wait after you whetted our appetites with yesterday’s tantalising glimpse.

Cheers

Dennis

ving
12-01-2006, 04:33 PM
it doesnt look to different to this image you once took and posted here a while back mike....

http://www.iceinspace.com.au/forum/attachment.php?attachmentid=1

davidpretorius
12-01-2006, 04:40 PM
i disagree, the is stronger ring structure in the newer one. Although the encke can clearly be seen in the older one, to us experienced astronomers there is a world of difference.

you youngsters couldn't spot that of course, by joves, you don't even wear socks & sandals, a very fashionable jacket and tie, and carry a pipe and tabac to observing sessions.

................mumble mumble mumble..................

ballaratdragons
12-01-2006, 04:44 PM
LOL! Clever Vingo!

Mike, that is a stunning shot! It is right up there with the best shots of Ringo. Well done.

Be Proud of it! (Mikes chest pops out)

Comet Hunter
12-01-2006, 07:06 PM
Nice shot Mike, a definate step up from last seasons efforts!

rumples riot
12-01-2006, 07:27 PM
Nice image Mike, obviously good seeing. This I believe is your best Saturn to date and still better than anything that I have produced. Congratulations. Persistence pays off. Don't know how you image during the week and go to work the following day. Just can't do it myself.

My only criticism of your great image is that the globe seems to suffer the same fate as mine with a squaring off of the planet near the junction of the rings. However, Cassini is nice and banding is smooth. Great stuff.

Paul

Striker
12-01-2006, 07:41 PM
Thats much better Mike...great effort.

All you guys are getting better and better every month.

acropolite
12-01-2006, 08:06 PM
Excellent effort Mike, very little difference between yours and birds, keep em coming.:D

iceman
13-01-2006, 06:01 AM
Thanks for the comments guys.


I agree Paul, and i'm not sure yet what's causing it. I don't know if it's the alignment framing in registax, or something to do with the image scale.

Look at Bird's bottom image (in DP's comparison shot) - the globe is nice and round and doesn't suffer from the distortion near the rings that mine does.

I don't know if it's just a consequence of the seeing, or something i'm doing during processing. Bird, any ideas?

davidpretorius
13-01-2006, 06:13 AM
i have seen a few examples of that squaring off. i almost thought it was optical illusion, until i relooked at birds???

matt
13-01-2006, 06:37 AM
Great shot Mike

Quick and basic question:

What does the "P=2.0" stand for in the details included under your initial pic of Saturn????

Cheers

matt
13-01-2006, 07:21 AM
Anyone??? Bueller .... Bueller....:lol:

iceman
13-01-2006, 07:27 AM
Matt, it stands for Phase. I answered it in the Jupiter thread where you asked it (with a little more detail than just now) :)

matt
13-01-2006, 07:35 AM
Apologies Mike.

Hadn't returned to the Joop thread since posting the quezzie:o

matt
13-01-2006, 03:28 PM
So how does the Phase scale work? What does the 2 represent, and where does the scale start and end?? (Lowest and highest points)?:confuse3: