Left my scope out all night to cool, got up at 3:15am this morning to image Saturn. Like yesterday, there were lots of clouds and it was even worse than yesterday.
Chasing the sucker hole again, though the difference today was that between the clouds the transparency was better than yesterday, and the seeing was also the best I've seen in quite a while.
Better transparency meant I could lower the gain for a less grainy final image, and there were a few more sucker holes which meant I could grab more frames. One of my stacks is a combination of 11 avi's! Each of them fairly short, captured during breaks in the cloud.
So, the details:
Set 1
- Gain 60%, Gamma 0, 1/25s
- 11 avi's stitched in virtual dub to give approx 3500 frames
- Stacked in registax (histostretch on)
- Image 1 (left, top row) is about 1700 frames stacked, wavelets processed in registax, ME deconvolution in AstraImage (4/1.2) and final levels adjustment in Photoshop.
- Image 2 (middle, top row) is about 1700 frames stacked, wavelets processed harder in registax, ME deconvolution in AstraImage (4/1.2) and final levels adjustment in Photoshop.
- Image 3 (right, top row) is after taking the raw stacked image from registax, and processing in PixInSight (Wavelets, SGBNR, histogram). Final sharpen and levels in photoshop.
Set 2
- Gain 60%, Gamma 35%, 1/25s
- 2 avi's stitched in virtual dub to give approx 2100 frames
- Stacked in registax (histostretch on)
- Image 1 (left, middle row) is about 1100 frames stacked, wavelets processed in registax, ME deconvolution in AstraImage (4/1.2), hue/saturation, and final levels adjustment in Photoshop.
- Image 2 (middle, middle row) is about 1100 frames stacked, wavelets processed harder in registax, ME deconvolution in AstraImage (4/1.2), hue/saturation and final levels adjustment in Photoshop.
Raw Frames (bottom row)
- Left image is the best raw frame (judged by registax) from Set 1 avi
- Right image is the best raw frame (judged by registax) from Set 2 avi
I'm very happy with these Saturn images, they're easily my best yet. On some images you can even see a hint of the Encke minima - the first time I've ever captured this "feature". On the Set 2 images, you can also see the inner crepe ring, thanks to the higher gamma setting.
When I started packing up at 4:40am, I just copped one last eyeball of Saturn through the eyepiece, and suddenly realised that I committed the ultimate sin - I hadn't checked collimation before starting imaging! So I checked it, and it was about 1/2 a turn out! Maybe the images would've came out even better if collimation was checked.
Anyway, very tired today after 2 early mornings of imaging, but when the results come out like this, it's worth it! (and yes, that's what i told Kate )
So I checked it, and it was about 1/2 a turn out! Maybe the images would've came out even better if collimation was checked.
these are rippa mike, well done.
i will take some time and digest. when you say raw, do you mean raw mode or simply a stacked image, no wavelets as bird was alluding to the other day.
on collimation, what alerted you to check when viewing it in the eyepiece? gut feel, or the view itself, or "****, i forgot and i better check"?
with mine, with temps under control and each night giving me experience and feel for seeing, collimation is one thing i want to stay on top off. As i focus on stars, i always note the way it focuses. With mars last night, i try and looked at a defocussed mars in the centre of the field of view and make sure it looks loveley and concentric.
The final test i spose is like a on the run visual on a planet, is there something about a planet in good seeing that can say "collimation is off a tad!"
As you say Mike, easily your best.
These are awesome shots and I would be wrapped if I took shots like these.
My Fav is Shot 1:Set 1 (sounds like tennis). Shows up the best on my CRT.
The colour looks spot on and detail is terrific.
i will take some time and digest. when you say raw, do you mean raw mode or simply a stacked image, no wavelets as bird was alluding to the other day.
In this case, I meant raw as in a single unprocessed frame from the avi. So imagine 3000 frames looking like the one in the bottom row. Although the one in the image is the *best* of the raw frames. I am using "normal" mode in the ToUcam, not raw/non-raw/optimised.
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on collimation, what alerted you to check when viewing it in the eyepiece? gut feel, or the view itself, or "****, i forgot and i better check"?
A combination of both of those.. I was looking through the eyepiece with my 15mm plossl and 3x barlow, giving 250x, and while the view was great and very smooth, I was expecting the cassini division to stand out more, to be sharper. Then it just popped into my head "oh bugger, collimation". So I put in the sight-tube/cheshire and found it was off. I corrected collimation and looked through the eyepiece again, the it appeared sharper to the eye this time, with the cassini division appearing crisper, and 5 moons easily seen scattered around the planet.
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The final test i spose is like a on the run visual on a planet, is there something about a planet in good seeing that can say "collimation is off a tad!"
Possibly, i'm not really sure. It's very hard sometimes to tell the difference between bad seeing, bad collimation or bad thermals in your tube/mirror.
Some more experienced people might be able to tell the difference between those 3 while looking through the eyepiece, but at this stage I can't.
I was looking through the eyepiece with my 15mm plossl and 3x barlow, giving 250x, and while the view was great and very smooth, I was expecting the cassini division to stand out more, to be sharper......it appeared sharper to the eye this time, with the cassini division appearing crisper, and 5 moons easily seen scattered around the planet.
i will have a rip tonight if weather is nice and seeing is good. asi's 5mm will give me 250x, so i will collimate, have a look, turn a knob 1/2 turn, have a look, turn a full turn have a look etc.
thanks for this info, that the division looked sharper after 1/2 turn, that is great info!!!
Just to clarify, I didn't "use" the cassini division to collimate on. I used my cheshire to check collimation, turned one knob 1/2 a turn until it was centered, and then put the eyepiece back in to view Saturn again.
Although it would be a good experiment, to try and collimate using the cassini division, get it to the point YOU think it's sharpest, and then chuck the cheshire in and see if you were right.
yes i intend to collimate with cheshire and star test, have a ambient mirror and then proceed to visually experiment with the division and the collimation screws.
The "4" is the iterations and the "1.2" is the PSF curve radius setting.
Open your colour image in AstraImage, and then use "Process->Split Colour Planes". Then on each Red/Green/Blue image, press the "ME" button, enter those values and hit ok.
Then go "Process->RGB Combine" and select the "Maximum Entropy" image for each colour plane and it will recombine them into a colour image.
I can't wait for Jupiter, it's teasing me low on the horizon while I pack up from a Saturn session.
It's actually too far South at the moment, I can't see it properly from where I've put the concrete pad on the grass! I'm sure it'll move further north as the months progress.
I can't wait for Jupiter, it's teasing me low on the horizon while I pack up from a Saturn session.
It's actually too far South at the moment, I can't see it properly from where I've put the concrete pad on the grass! I'm sure it'll move further north as the months progress.
Matt, a tip, after doing each colour deconvolution, go to edit and rename each one ie ME-blue, ME-red, ME(4)(2.4)-blue.
if you start experimenting, then you will forget which colour is which and which has given you the be recombine
mike, jupiter is great from down here. We have a mountain roughly due east and it is rising south of that. It is rising further south than orion was, so it is going to be a bottler!!! About the same place as sirius!!
bring the family down for a trip and we can play nerds in my dark sky driveway whilst the ladies have coffees and the kids rip the house apart!!!
Maybe the images would've came out even better if collimation was checked. 
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