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Saturn and 15 MP Moon - March 4

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#1 MvZ

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Posted 06 March 2013 - 12:00 PM

Both imaged with the 10" Starfinder and the ASI120MM in the early hours of March 4 under poor/decent seeing conditions. Saturn was about 24 degrees above the horizon, and the Moon even lower at just under 16 (!) degrees.

Saturn: R-RGB
Moon: Ir (>807nm) @ prime focus (with drizzling)

Even though the seeing wasn't very good (especially for Saturn the green and blue channels were very poor), it was still very nice to finally be outside imaging under the stars again.

The image of the Moon is a full mosaic imaged at prime focus.
http://www.astrokraa...1313_stitch.jpg

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#2 Rankinstudio

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Posted 06 March 2013 - 12:02 PM

That is a really nice shot Emil. I would be proud if I made it. Very nice processing.

The moon stitch is amazing as well.

#3 sfugardi

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Posted 06 March 2013 - 12:24 PM

Emil, excellent images! Even more impressive at those altitudes. Processing looks great on both shots. Thanks for posting

Regards,
Steve

#4 mitovka

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Posted 06 March 2013 - 12:36 PM

Great Saturn shot Emil. I like the processing much, it looks totally noise free but still natural. How do you sharpen your stacked images (if it is not secret)?

#5 MvZ

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Posted 06 March 2013 - 03:29 PM

Thanks!

It is not really a secret, I simply don't have a standardized way of processing. This makes it difficult/impossible to explain what exactly I did, because it was a lot.

Sharpening of the images was entirely done in Photoshop using a mixture of techniques, mostly done by just experimenting a lot. I know I did unsharp masking, and some modest smart sharpening, but I also emphasised a little bit the darker contrasts in the image.

But perhaps the most important thing is that the image is an R-RGB image. I actually combined two R recordings, and added a little bit of green as well (20% or so), to create an artificial luminance channel. This made for relatively noise free data to work with.

I have also been experimenting with several different noise reduction plugins lately, I don't like the standard Photoshop noise reduction.

Basically I use a lot of tools, but pretty much everything with moderation. Too much sharpening or too much noise reduction gives you results I don't like. If you think an image is sharp enough, you have probably sharpened it a bit too far already.

But part of the fun - at least for me - is to simply experiment a lot. If I could get a perfect image with just a single press of a button, most of the fun would be gone.

But perhaps that is different if you can image every night ;)

#6 ToxMan

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Posted 06 March 2013 - 03:39 PM

pretty much everything with moderation



That is the key!

Lovely images, Emil.

#7 Kokatha man

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Posted 06 March 2013 - 09:11 PM

A nice Saturn, and at 24 degrees you really had your work cut out to bring it up to this level Emil! :cool:

ps: ...what frame-rate were you using..? :question:

#8 wenjha

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Posted 06 March 2013 - 09:29 PM

that's great image for a 24 degree!

#9 MvZ

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Posted 07 March 2013 - 05:41 AM

Thanks!

Darryl, I think I used 30 fps with close to maximum gain.

#10 lcd1080

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Posted 07 March 2013 - 10:42 AM

Emil I especially like your clear capture of the central portion of the Cassini division despite Saturn's low 24 degrees elevation. I was wondering what program you used to create the artificial luminance channel with the two R recordings and one green recording. After you created the luminance image am I right in thinking that you formed a final LRGB image in a program like AstraImage 3.0SI?

Thanks,
Pete

#11 MvZ

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Posted 07 March 2013 - 10:58 AM

Hi Pete. I do those things manually in Photoshop.

So first step is the manual alignment of multiple R en G channels as layers on top of each other, with opacities depending on the quality/noise level of each stack. Then I merge these, and use the resulting layer as a luminance layer for the RGB recording. The cool thing is that you have total control this way, you can decide how you want to build the luminance your way, depending on the images you have available. After a bit of practice this doesn't even take that much time. So in this case I used one R for 40% on top of the other R channel, and added only a bit of green.

Of course you have to realize that the resulting 'R with a bit of G as L'-RGB won't give you a perfect rendition of the colors, but in this particular case I preferred details over accurate color rendition. Also by changing the brightness and contrast in the resulting luminance image, you can get pretty close to the colors of a 'normal' RGB.

#12 shawnhar

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Posted 07 March 2013 - 11:04 AM

Very nice, hope I get some of that poor to decent seeing, mine has been utterly horrible.

#13 mikewirths

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Posted 07 March 2013 - 02:19 PM

Emil a beautiful Saturn and I especially like your moon stitch!! Just wonderful details! I think your processing is spot on, great tonality in the maria! I like smart sharpen too, and if you get a chance check out topaz infocus or focus magic, they introduce less noise than USM.

cheers


Mike






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