A Late Season Saturn in Good Seeing (repro added)

[iceman]

On Sunday night, 3rd May, I was out capturing some images of the Moon for a friend and even though I was using the ED80 and DMK, I noticed the seeing was quite steady so once finished with the Moon, I put the 12″ Newt back on my EQ6 mount.

I was pleased to see Saturn quite steady on the screen, with the Cassini Division visible in the raw video during moments of stable conditions. I only captured 2 runs, as I knew the seeing wasn’t going to get any better at that time, but it was enough to capture my sharpest image of Saturn this apparition - a great surprise for being so late in the season.

More here:
A Late Season Saturn in Good Seeing (http://www.mikesalway.com.au/2009/05/06/a-late-season-saturn-in-good-seeing)

edit: REPRO added (on the right).
Thanks for looking.

[Lester]

Nice and sharp Mike, just a tad blue for me.

[iceman]

Yeh it's blue on this laptop too but looked ok on another screen.

It's so blue because the blue channel was captured at 7.5fps, whereas R and G were captured at 15fps, so the blue had more intensity when recombining.

I tried to reduce it a bit during PP but may need to go a bit further.

Thanks

[Lester]

Mike in relation to different exposure with coloured filters; I have been looking at the Astronomik and Astrodon filters, (seems the Baader ones I got are not the best) they say the same exposures can be used for these filters, obviously you do not find this with your Astronomik filters?

[iceman]

It depends on the object, the seeing, the altitude, etc.

For Jupiter, I use 30fps for all 3 channels, and just adjust the gain to get the same histogram for all 3 channels.

For most filtersets, they don't all have the same cutoff in each channel. For the astronomiks, the green channel is almost always brightest, and blue is almost always dimmest.

Saturn is so dim at the moment, that even at 15fps for R and G with 100% gain, the histogram was under 50%. On the blue channel at 15fps, it was just too dim so I dropped to 7.5fps and the histogram was about 50% for blue.

The astrodon's that Anthony uses appear to be very good.

[Lester]

Thanks Mike, I appreciate it.

[bird]

Good image Mike, pity you can't fix the colour balance :-(

For filters, if you're imaging something close to the zenith then you'll get the best results, as you get closer to the horizon the blue channel is extinguished much faster than the red so the balance will be out.

cheers, Bird

[Paul Haese]

Nice image this one Mike, sharp and well processed. I am not fussed about the blue, but you could change the channel intensity in Astra Image. I have found that having blue at about 1.3 or 1.4 is about right generally. This would be slightly different for your setup and exposed frames.

[Quark]

Nice sharp image Mike,
Well defined structure but agree with Bird about the colour. Overall a top result especially considering the run you have had with the weather.

Cheers
Trevor

[kinetic]

Beautiful shot Mike....
Did you give the scope any cool down time once
you did the ED80 swap or was it straight into it?

Either way, looks brilliant.
I did notice the seeing here Sunday night was awesome too.
I was doing a visual with the kids on the Moon with our old
8" homemade that night too. :)

Steve

[dpastern]

Looks good, but Bluish to me Mike. Is it possible to reduce the Blue channel in Photoshop by 50% (opacity)? That should balance it with the R & G channels no? Or am I barking up the wrong tree?

Dave

[Inmykombi]

Nice work again Mike. Plenty of detail showing the cloud bands.

Well done.

[Screwdriverone]

Hi Mike,

I agree on the blue hue, but the focus, detail and the size are fabulous, nice job!

Must drag my sorry rig out soon and see if I can get another shot or two.

Well done.

Cheers

Chris

[iceman]

Thanks for your comments, all.

I've added a reprocessed version and got rid of the blue :) Hope it's more pleasing.


No cooldown, just put the 12" on and started. There was a 3° difference in temp between mirror and ambient which affected the local seeing.

It's getting harder to image just after sunset now, no time to cool the scope and it's right in the middle of happy hour.

[bird]

Ok, the repro version has much better colour. Thanks!

cheers, Bird

[Quark]

Mike, the change in colour balance is great and adds so much to the overall look of the image.

Just for a bit of perspective, I have been going back through my old copies of Sky & Space. In June / July 2000 page 58 there is a Saturn image by Shigemi Kanbara of Japan taken with a 16" LX 200 and in the April / May issue page 59, a Saturn image by Steve Massey taken with the 60 cm Scope at Siding Spring Observatory.

These were no doubt excellent examples of the state of amateur astro photography at that time, however there is absolutely no comparison between either of them and either of the two versions of the image you have posted here.

It is really such a comment on how far amateur equipment, imaging and processing ability has come that we now look at stunningly detailed images taken by amateurs and comment on the colour balance because we are getting use to the level of detail that is in them.

What do you think?
Cheers
Trevor

[iceman]

You're right Trevor - the images that amateurs can capture these days is amazing, compared to the results even professionals were getting under 10 years ago.

I lot of it has come down to the camera and processing technology, rather than the equipment itself in my opinion. And I can see it only getting better, with faster, more sensitive devices.

[Alchemy]

very nice mike, clean, contasty see the split in the rings and the belting around the planet.

clive.

[dpastern]

Looks good to me Mike. How did you end up fixing it?

Dave