Help with Jupiter processing please

[Helen]

Over the last few nights I've been taking shots of Jupiter with my C11 and an ASI120 colour camera.  I have a feeling (I'm hoping!) that my processing skills are not good enough to get the most from the data.  This is based on the shots that other people are posting with similar kit.  Would anyone be prepared to have a look at some of my data and see whether anything can be done to pull out more detail?  or give me tips on how to gather better data?

Thanks

Helen

[jambouk]

Helen

I recently helped a chap with a semi similar question; though he is using a dslr, just ignore the dslr comments.

http://stargazerslounge.com/topic/240767-first-attempt-stacking-failure/

I'm happy to have a look at the data. Can you upload the raw video of a hosting website like drop box and i'll download it; if you post the link there, others will likely have a go too.

James

P.s. Can you post the final image here for us to see? Did you use a barlow or powermate? What capture software dis you use? How dis you focus, what was the seeing like, how long is he video (what fps was it show at)? Etc?

[PeterCPC]

What I do :

Run the AVI through PIPP first and employ the quality options

Run the resultant file through AS!2 and ask to keep maybe 70% of frames

Put the resultant PNG file into Registax to use wavelets, denoise, RGB align etc

Put the resultant image through a image processing package (I use PaintShop Pro) and generally fiddle with the various adjustments like levels, curves etc

I don't profess to be good at processing but you just need to keep practicing. Good luck.

Peter 

[Helen]

Thanks  Lots to read there.

Here's a link to one of the smaller files https://www.dropbox.com/s/bg6936jsob5py31/2015-04-07-2322.6-L.avi?dl=0  Have fun!

Thanks again

Helen

[jambouk]

The moon which appears in frame looks big; this suggests to me the focus is off. The seeing seems pretty good compared to most of the seeing I've had.

I'm trying to download the data but it's being very slow.

James

[Helen]

Thanks  maybe hang fire on this one if the focus isn't good.  I'm going to go out tonight and try again.  I'll work harder on focus - the challenge has been mirror shift, so I'm going to try an external focuser (thinking my borg helical might be good)

Helen

[jambouk]

I ran the video through PIPP and cropped it and quality aligned it; used all the frames and loaded them into Registax 6; auto alignment points (I'm lazy), picked best 75% of frames and aligned, limited and stacked. Did RGB align and altered wavelets in Registax, saved file. I've re-sized it to 75% of previous size serially so you can see how making it all smaller improves things

Others may disagree about my focus comment, but that moon did look big and blobby to me. There are various ways to try and focus (none are easy with planetary); I find the easiest one is to temporarily increase the gain and exposure time so a moon is brightish, and then alter focus to get the moon as small as possible, then go back to Jupiter, re adjust your settings and image.

You shouldn't have trouble with mirror shift if you are focusing and imaging straight away; mirror flop occurs, I believe when the scope flops from one side of the meridian to the other (something you are not doing during a 2 minute run on Jupiter (I hope)). What do you mean by mirror shift? Check out where the Jet Stream is, that is a big factor on how good and stable the seeing is. 

An external focus on a 180 Mak is good, especially if you can motorise it and make small defined adjustments remotely whilst looking at the laptop screen; Damian Peach, my hero (lol), says trying to do planetary imaging without a motorised focuser is daft (or something along those lines). You want to be watching the laptop for perfect focus, not trying to keep your eye on the focus knob and the laptop.

It's certainly a really good start at this. Are you imaging with a Barlow or Powermate too?

James

[Helen]

Thanks James

With mirror shift what happens is that as I focus the image moves (caused by the fact that on an sct you move the mirror to focus).  It often moves off the frame completely at higher magnification    The external focuser seems to be a bit easier.

Here's my first attempt tonight - just at f10 for now

Helen

[Helen]

..and at f25 

Helen

[jambouk]

I have an SCT and i've not noticed mirror shift as bad as you describe. But yes, a crayford or the like will help, and would make motorising the focus mych easier. You can get the standard crayford for about £100 but if want to motorise it it might be better to get a more expensive one, i don't know. I bodged a motor up in a revelation astro crayford which works ok for me.

The two images are nice. I do like the f/25 one best, but might aome of the inprovements be due to telesxope cool down, atmoapheric cool down and maybe a patch of better seeing and not just a change in focal length?

How did you find focusing?

James

[jambouk]

Helen,

Your images (and data) have a glue / blue hue on my desktop. I've grabbed a similar Jupiter images of Google images and pasted them along side one another to show you. Not sure where in the data acquisition or processing this happens, but something else to try and figure out... such a learning curve isn't it! Keep going, you are doing great.

James

[cuivenion]

As far as focusing goes could you not use a bahtinov mask on a bright star and then slew to the planet?

[jambouk]

Yes, using a bhatinov on a very near star (important to get one as close as possible and on the same altitude), but no saying the precise focus on a star 100 million light years away is the same as on Jupiter 600 million km away

Llus if there is a floppy mirror, you really don't want to be slewing the scope at a fast rate once you've fuxed focus.

James

[cuivenion]

So are Bahtinovs only good for DSO's then, not for planetary.

[jambouk]

Don't use a bahtinov on a planet; but people do use them on a near by star when doing planetary imaging

[catman161]

There's multiple posts about use of bhatinov masks for planetary. Personally I have tried one a few times and they just do not work for me, the focus is perfect on the star and way out on the planet-they two just do not equate.

James (Jambo) and I were lucky enough to speak with Damian peach in person a while back and he advocates the wait and watch method. Wait for those fleeting moments of clearer seeing and adjust focus a tiny amount, then wait for the next fleeting moment of clear seeing and see if your adjustment helped or made things worse. Keep doing that and then hit capture when you're happy. I have done this for over an hour before hitting capture previously. The end result is (in my experience) better using this method.

Sent from my iPhone using Tapatalk

[jambouk]

I still prefer the small moon method.