Saturn - 18th Dec

[iceman]

Hi

Here's Saturn from yesterday morning. Seeing was barely 5/10, and transparency was average, too.

I captured luminance + RGB data @ 15fps (1/15s), with both the 3x barlow (top image) and the 5x powermate (bottom image).

400 frames were processed in registax, followed by LR deconvolution in AI and Photoshop for combining the luminance and RGB layers.

I used a less processed version for the rings and a more processed version for the globe, to reveal the banding on the globe without overprocessing the rings and making the cassini division even wider than it is. Unfortunately there's a few registax joins in there as well.

Not my best for the season, but good to be out amongst it again after 7 weeks of no imaging!

Thanks for looking.

[Dennis]

Very nice images Mike - I bet it was great feeling to be out again after a 7 week hiatus! Any problems remembering how to operate the gear after the long lay off?

Cheers

Dennis

[John K]

Great work Mike, it's a tough object at the moment!

[iceman]

Thanks Dennis and John.

Dennis everything came back to me fairly comfortably out in the field, it was the processing routine which I had to refamiliarise myself with.. I couldn't remember how I processed Saturn images to get the best out of them :)

Anyway it is good to be back out there.. the familiar tired feeling after being up from 3am and then going to work :)

[Robert_T]

Nice one Mike, I was sooo tempted to get up this morning for Saturn but couldn't get motivated knowing the pre-christmas work mayhem I need to get through.

Seeings pegged back the sharpness on this, but it's got some of the best banding detail I've seen on Saturn's globe - well done!:thumbsup:

cheers,

[bird]

saturn's hard enough this season without having to deal with all the smoke etc around at the moment, transparency is worse than I've ever seen it. We've just gotta keep trying...

Bird

[matt]

Well done Mike. Very nice given the conditions.

The resulting loss of sharpness is very reminiscent of the seeing we get most nights here in Canberra:(

It's always interesting to view the impact of seeing/transparency etc on other imagers in other locations. Good to have something to compare with and get an idea of whether we've rated the seeing in our part of the world fairly:)

Rob's right. You've done a great job with the banding on the globe.

Hope you/we get some clearer and cleaner nights soon. This cloud and smoke is driving me nuts!

[ving]

top job mike :)

just a bit curious tho, I have never imaged (properly) saturn. is it like jupiter where you can only grab a couple of mins worth of avi otherwise you get blurriness or can kyou grab more because of the lack of surface detail?

[iceman]

Thanks guys.

David, both :) If a storm is present, then you should capture it like Jupiter - that is, shorter avi's so you don't "smear" the features.

However most people just capture for longer to get more frames = more frames to stack = smoother image with lower grain/noise.

I capture for 2 minutes on each channel, and an additional 2 minutes of luminance - though i'm not too happy with how the L channel is turning out. I don't know if it's blocking IR.

For Jupiter, it's 2 minutes MAX (all channels combined).

[matt]

Mike

Could you explain why you capture in luminance as well as RGB?

I'm still considering the purchase of a monochrome cam and filters but still don't understand the process as well as I should

Thanks;)

[ving]

thanks mike :)

[Robert_T]

Ving you should be able to image Saturn for longer than Jupiter without smearing - because of it's greater distance and smaller size the movement of a feature from one chip pixel to the next should take longer. 4 minutes capture time is not unheard of, though I'd generally do less.

cheers,

Bob

[ving]

thanks bob :)

[iceman]

When combining the luminance layer with RGB, it's supposed to help you end up with a smoother image - there's more light transmission in the clear L filter and so the gain can be a bit lower, or a higher frame rate can be used. So you can hopefully end up with a nice smooth monochrome luminance image, and use the colour data from the combined RGB image by using layers in photoshop.

For the 5x powermate image, I captured at 30fps for the Luminance and 15fps for the RGB channels.

However, it doesn't always work out that it gives the best image. My limited experience to-date is that the luminance channel appears softer, even though it's brighter. Interestingly, Bird said as much on another thread over on CN.

It might be to do with the altitude or poor transparency we have for Saturn at the moment.

Earlier this year when I first got the DMK (before I had colour filters), I captured monochrome for Jupiter with the DMK as the luminance, and used the colour data from a ToUcam capture, and combined them. For that image, it turned out great. The detail in the monochrome image was already there, and the colour data added from the ToUcam really looked great.

I can't find it right now, but i'll post it tomorrow.

[matt]

Thanks for that Mike

I ordered the Robert Greeves book "Introduction to Webcam Astrophotography" today from Bintel.

While I know how to use a Toucam etc I'd like to gain a better understanding of how ccd cams work.

It also looks like it has some handy info on processing.

Might be inspired to write a review after I've had a few reads and put some of its knowledge/info into practice

[davidpretorius]

love it mike, congrats

[erick]

Please do, Matt, and advise whether a complete novice (c'est moi!) will learn a lot from it! ;)

[iceman]

Found them, here they are.

Luminance from the DMK, and colour data from the ToUcam. Man, I wish I could capture Saturn like this! I wish I had seeing like that again!

[matt]

Thanks for digging that out, Mike.

Ahhhh yes. Memories of great seeing nights past.

When... oh when.... will it all return?:lol:

[Dave47tuc]

Nice Saturn image;)

So would you say seeing is the number one most important thing in imaging?

[iceman]

Yes, always!

Though, if you have other factors under control as well (collimation, ambient temperature, focus, capture + processing), then you are able to get the most of out the conditions..