Mike vs Dob vs Saturn - Round 2! Ding!

[iceman]

Well after giving up all hope of being able to have another imaging session before having to give the laptop back today (weather has been absolutely lousy), this morning was finally clear.

One of the kids woke me up at 12:45am, put her back to bed and went and looked outside, it was clear!!!

Had to take advantage of the only clear night all week, so setup outside with the imaging gear and tackled Saturn for the 2nd time with the new ToUcam.

I learnt a lot of lessons from my last experience, and thanks to some great advice from people on this forum and on CN, I had a better handle on what settings to use when capturing Saturn.

I tried at prime focus (f/5) for the first lot of videos, with the (make me blue) IR filter on, they came out ok but didn't end up too much better than my initial attempt.

I put in my light-obstructing barlow and imaged a few vids at f/10, and after getting sick of looking at blue I took out the IR filter. Straight away it looked better on the preview screen.

Took a few more vids with some slight adjustments in settings, trying to make it dimm enough but still be able to find the damn thing on the preview screen when I have to nudge the dob about.

A few other lessons learnt this morning:

1. Gawd i'm sick of this already :)
2. At f/10, I get about 10 seconds of frames before it drifts out of the FOV and I have to realign. Means taking lots of 10 second videos and joining them together afterwards. It works, but it's painful and frustrating.
3. I need to be more careful with focus and ensure it's spot on, instead of "looks right".
4. Aligning your finderscope with the eyepiece does not mean it will be aligned with the CCD chip.
5. Aligning your finderscope with the CCD chip is a painful and frustrating process, but essential.
6. I need to work on my azimuth motion again, trying to nudge the dob when the swivel motion sticks makes things even more painful and frustrating as Saturn whizzes out of the FOV when trying to put it back on the right-hand-side, and then have to spend another 30 seconds trying to get in back in view again.
7. I need some red LEDs on the objective end of my finderscope to illimuniate the crosshairs.. trying to position a dot on some black crosshairs against a black sky is painful and frustrating. Holding a red torch shining at the finderscope with one hand and trying to nudge the dob with the other is painful and frustrating.
8. I need more diskspace! My imaging session ends whether I want it to or not, when I use up the 1.5Gig of free disk space. (I transfer it to my other computer when i'm done).
9. I want tracking!
10. I'll never be able to image at more than f/10, there's no way i'm going through this painful and frustrating process every 3 seconds let alone every 10 seconds! :bashcomp: :)
11. The Cassini Division is not straight and round! See my images below for proof! :lol:

Anyway enough blah, onto the images..

First lot is the raw stacked images, stacked about 300 of 750. If you're able to process them better than me, I'd be most grateful.

http://www.iceinspace.com/images/images/planets/20041206-saturnx3-rawstacked.jpg


Second lot is after my wavelet processing attempts, with some minor adjustments in photoshop as well.

http://www.iceinspace.com/images/images/planets/20041206-saturnx3.jpg

So, how 'bout that Cassini Division!? :whistle:

Can anyone enlighten me as to the possible causes?
1. Focus not sharp?
2. Collimation off?
3. Seeing bad?
4. Not restrictive enough when aligning/stacking in registax?
5. All of the above?
6. None of the above?

Appreciate any help or suggestions.. this image is already 5 times better than any previous Saturn image i've taken so although I'm in pain and frustration, i'm still pleased that it's finally recognisable as Saturn! :lol:

Thanks

[Saturn%5]

Hi Mike,
Im not much of an expert on this but i tried doing what you are doing on my 12" dob and well was not happy with the results but i was using the lpi.

I hate to say but i think you nailed it on the head with your problem list i think you need tracking on the dob or you are never going to get great results on the gas giants the moon is different kettle of fish. I would try that first to see what you can get Dont give up you will get there,

I will try to get Mark over with his notebook and webcam and see what we can come up with using the same method as you.

That is if the :cloudy: ever go away.

Keep trying i know how you feel but trust me :scared2: you will get there.

[rumples riot]

First of Mike, this is fantastic progress. Now you can see the image and some detail is present.

Second, raise you minimum quality level a bit higher. The better the shots the better the final stack. Bad images create poor stacking and registration. For planets I have used 50-75% rejection on the LPI. Tracking is certainly a problem you will have to overcome. That said, Wes at CN does exactly what you do, I don't think he has any tracking. Aslo consdier that Saturn is unfortunately in a bad position for us at the moment. Even at its highest, it is not anywhere near the zenith. More air to disrupt the image.

Also your focus is still a bit out and I would either check your collimation or get another apo based barlow. I can see blue around the edges in the originals, a sure sign that something is not quite right in the light train. Try to focus on one of the moons, Focusing on stars is ok for deep sky work, but only rough for the planets (at least that is what I have found). And; if you do not already have one, a hartman mask would be good. Then you can focus directly on Saturn itself.

Other than that you have made a huge leap from last time and I expect to see your shots better all the time.

Keep it up.

Paul

[iceman]

Thanks for the comments and suggestions guys.

Wes does have tracking though, he's got an 18" Starmaster and it's sitting on top of a big EQ platform.

There's no way you could get the image scale he does without tracking! His images are superb.

[ving]

wicked!

yeah you could do with tracking but welcome to the wold of dob use :p
I wanna try shooting saturn soon (sorry saturn)

[beren]

Keep at it Ice , if it was to easy it wouldnt be so damn addictive. Even having x amount of focusing and slewing speeds i experiance frustration so your progress is great] going

[seeker372011]

Ice:

I came across this software that I haven't been able to try because of the weather but looks really terrific..I have been playing with it with a webcam -not really connected to a scope-and it tracks objects really well

http://www.astrosnap.com/

the point is this allows you to track an object even when your mount can't.

think it could well be worth a try..some features are sensational..dont know if ayone has actually used this, but from the description it sounds fantastic..can't wait for a clear sky..no doubt sometime in 2005