Burst Bubble

[Shelster1973]

Well.....where do I start.

Having decided to focus on one target only for the winter time, decided on the great looking Bubble Nebula.

Managed to get setup the other night (Tuesday) and thought I was in for a good 6 hours of data gathering.  1st run off and running on gathering some Ha as a basis.

Checked after 1st hour and focus had shifted off....oh joy.  So reset focus as best I could and went again.  Checked after another hour and it appears I have fallen fowl of the bubble being of a stupid high ascension and it caused my tube to foul on pier.......ended up with lots of ruiined subs and after checking it appears to have thrown the mount out of PA.

All I managed to salvage was 3 x 900s subs.  Have very quickly thrown these through PI.  No cal data, just subs.  Have done some DBE, Noise reduction, stretching and curves on it.

As you can see, focus is still off and need to work on my collimation (still).  I did some playing with spacing between my CCD and coma corrector, but think I may have to do some more tweaking.  Plan is to bring scope inside house and do adjustments on very distant target in daylight so that I can see how much I need to adjust.

Anyway, here is a JPG version of what I managed to get.

Guess I need to find me a new target now

 

[PatrickGilliland]

Hi there

To start with all progress is good progress and you have some photons trapped and output  Few observations (if you are already doing than you can ignore me)

The hobby will very quickly become frustrating with limited sky opportunities when avoidable problems ruin a session.  Purely based on your comments it may be that you scope needs to be repositioned, if this requires addition of weights to balance out the set up then this is what you do.  I have an assortment of handy bits of stuff laying around the obsy from old batteries taped together (or as i call it my modular balancing solution) to some small iron blocks and weight.  The scope should be able to travel freely throughout all points and axis.  If using a newt ensure scope is rotated so as to be away from mount and not towards it at any point in its travel.

Focus is key closely followed by accurate guiding or tracking. You have obviously invested in some kit and i would stress the next purchase you must make is a motorised focuser.  You can use a bahtinov mask as a cheap effective manual solution but very few will get consistent accuracy even with a mask (you can pick one up for c£20 or less).  I would invest in an autofocus solution.  Before you do though when you say your focus shifted consider if this is because you have a poor focuser or whether this was 'typical'.  Be typical i mean as conditions change in the sky, and your scope adjusts to ambient effects such as temp and movement you focus will always move.  If the focuser is not moving in or out that's fine.  Your focus will go out periodically on all but the most stable nights.  You need to watch your FWHM or HFD to monitor over what period this occurs.  This will suggest the re-focussing period required.  I run a top end scope and will refocus every 40-50 minutes.  It has to be done, simple as that. If focuser is good get it motorised and let it do all the work.  It will likely be more accurate than you or I will ever.    Considering the how out of focus the image is the set up shows great potential and this simple change will make a world of difference to you images.  It will also provide repeatable and easy process to get focus (first few nights of learning are a chore but once done its a single mouse click, or if using SCP/ACP its just done during the image run!)

As a rule of thumb you will want 20+ subs per channel to really see the best SnR.  Fine to have a look around during the learning process but the sooner you start to do that (with all the other bits sorted) the sooner you will realise the true potential of the kit.

Pop me a mail if you need any help.

 

You should be encouraged that despite the 'missing bits' there is actually potential in that data.  Just need to iron out the kinks and do all the prep work.

Paddy

[Shelster1973]

Paddy

Very many thaks for taking the time to draft such an indepth and very helpful post.  Is some very well received advice and pointers.

Have the tube off at present, so will look at moving it further up the saddle when I refit, so helping with the clearance.  Have stacks of random bits and bobs in my loft shed, so can use some of these are counterweights where needed.

Going to really take my time when doing next collimation.  Have a cheshire, so no excuses on that front after I have finished.

Have a mask too, so will be using this next time out as well.  The shift in focus I beleive is down the change in atmospherics and temperature.  Was a rather cold night and think that there was a rather rapid drop in temp between me carrying out the initial focus and then when I went out to recheck.  I do have an motorised focuser, it was just not working that night.  I have put together a stepper motor based on the Arduino Nano, which was all found here on these wounderous sites.  It had been playing me up for a while and have finally got round to taking it apart and debugging it.  All is working well and now just need to mount it back on the OTA.  It is recognised by SGP, so am hoping that I can use the focusing routine in that to get me there.  Have also revisited the spacing in my optical train and removed some spacers that I put in last time and am now spot on at 55mm spacing.  Not sure why I ended up putting in too much last time, but hey ho....sorted that issue.

Now just need to remount, realign using PHD2 drifting and then should be good to go agin.  Did mod my mount to put in some silly fine threaded az adjuster screws, so have very fine control over adjusting azimuth to get it very close indeed.

Onwards and upwards......

[PatrickGilliland]

1 hour ago, Shelster1973 said:

Paddy

Very many thaks for taking the time to draft such an indepth and very helpful post.  Is some very well received advice and pointers.

Have the tube off at present, so will look at moving it further up the saddle when I refit, so helping with the clearance.  Have stacks of random bits and bobs in my loft shed, so can use some of these are counterweights where needed.

Going to really take my time when doing next collimation.  Have a cheshire, so no excuses on that front after I have finished.

Have a mask too, so will be using this next time out as well.  The shift in focus I beleive is down the change in atmospherics and temperature.  Was a rather cold night and think that there was a rather rapid drop in temp between me carrying out the initial focus and then when I went out to recheck.  I do have an motorised focuser, it was just not working that night.  I have put together a stepper motor based on the Arduino Nano, which was all found here on these wounderous sites.  It had been playing me up for a while and have finally got round to taking it apart and debugging it.  All is working well and now just need to mount it back on the OTA.  It is recognised by SGP, so am hoping that I can use the focusing routine in that to get me there.  Have also revisited the spacing in my optical train and removed some spacers that I put in last time and am now spot on at 55mm spacing.  Not sure why I ended up putting in too much last time, but hey ho....sorted that issue.

Now just need to remount, realign using PHD2 drifting and then should be good to go agin.  Did mod my mount to put in some silly fine threaded az adjuster screws, so have very fine control over adjusting azimuth to get it very close indeed.

Onwards and upwards......

Good luck let me know how the focuser works out.

Paddy

[Shelster1973]

Cheers Paddy and will do.

Am thinking Wizards Neb as my new target of this time.....checking on the astronomy.tools fov tool, frames up very nice and also has some good stars in frame to assist with focusing.

On the bench the focuser works a dream when controlled via the program that came with it to test and run it.  Knowing my luck it will all go to a ball of chalk when I try and automate it, but I do like a good challenge...and there is no way I could afford to get a new focuser and motoriser for it without my numbers coming up....fingers crossed on that one