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Heart Nebula IC1805 WIP

Started by Carole, Dec 30, 2013, 11:02:49

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Carole

My first image for 2 1/2 months.  Managed to get out on Friday night.

Would have preferred to have posted this when I had more data but goodness knows when that will be, and as Robert was asking whether any-one was still imaging I thought I would post it up as a work in progress.

Warts:
1. I have posted up the Ha separately as the quality of the Oiii (I think I'll need several hours of this or a dark site) is spoiling the sky background of the combined image.  
2. NO Sii done yet so I did a made up false image for the 3rd channel sort of combination of Ha and Oiii.  
3. Been having some awful alignment problems since Kelling, one of the reasons I haven't done anything for ages kept missing the target and couldn't successfully align.  Checked and re-checked everything, even alignmaster couldn't cope with it.  I am starting to wonder whether I have polar aligned on the wrong star but need to wait for a clear night to re-check this, yet the PHD graph was as flat as a pancake.  In the end I decided to give EQMod another try and now I am using a finderguider I find it a lot easier as I don't have to look through the finderscope whilst trying to use the laptop.  Using the method of slewing to a nearby star and syncing has worked.
4. Spacing is spot on but the stars on the top left side are elongated and finally I have come to realise I need an adapter to make the camera orthogonal, why on earth do they put only 2 screws onto a drawtube to clamp a weighty camera - this obviously is for the future and meantime I am cropping out the top left side.  Has any one got one of these and is it easy enough to use?

The image:
12 x 600secs Ha Baader
6 x 600secs Oiii Baader
Atik383L
Finderguider QHY5
WO ZS71 & focal reducer = F4.8
Temperature - 15
Stacked in Astroart, registered in Registar and processed in Photoshop CS3
Also my first light with the PZT (couldn't have reached the object without).

The Ha version:


The combined Hubble bicolour:
N.B I don't like those gawdy bright yellows and blues, so I am going for a more subtle hue.



Close up of the Heart of the Heart:

Rocket Pooch

Not sure it looks in forcus or the guiding is ok, I think your much better and more experianced than this image.

Mike

Looks good to me Carole and kudos for you getting out in this freezing cold and wind to image. It will look good once you've added a few more hours of data to it.
We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology. Carl Sagan

Carole

Thanks Mike. 

I know this needs a lot more data and probably some dark skies, but I can't save up all my imaging for DSC. 

Carole


Ivor

Well done Carole, good to see someone is getting out there. I'm not sure what it is with the posted images there appears to be some distortion around some of the stars, I'm not sure if this is left over from your processing or due to the JPG compression.

AA5 has a filter under FILTERS->COSMETIC->REDUCE STARS which deals with the elongation quite well. If you have problems let me know and I'll talk you through it.

I look forward to seeing this with more data.

Carole

Ivor:
I can't see any distortion that you mention, but what I can see is fuzziness in the background which is due to the poor quality of the Oiii data which I had a lot of problems with and this is why I posted up the mono image too.  I am hoping this will be better once I have some better Oiii data.  The close up is a PNG file so if it's that one you are referring to their shouldn't be any Jpeg compression.  

I also can't see any focus or guiding problems referred to by Chris, except I did do a despeckle to clean up the image a bit and this can sometimes very slightly blur an image, especially one zoomed into a lot.  But I agree I could do a better image given the opportunities and a better location.   However this is where I live and I have to make the best of it.  I'm not experienced at narrowband imaging and need to practice and find out what can and what can't be done from Bromley. 

Carole


Ivor

I think I might have found the problem, to my eye the image appears sightly differently when viewed in Chrome against Firefox or IE. 

Jim

<<Spacing is spot on but the stars on the top left side are elongated and finally I have come to realise I need an adapter to make the camera orthogonal, why on earth do they put only 2 screws onto a drawtube to clamp a weighty camera - this obviously is for the future and meantime I am cropping out the top left side.  Has any one got one of these and is it easy enough to use?>>

Hi Carole, I had the same problem but solved it by drilling and tapping another screw into the drawtube. It's quite easy to do, you can pick up a die and tap set at screwfix quite cheaply.

Carole

Thanks Jim, Yes this is one of the other options I was considering, but I would have to get some-one to do it for me, never done any metal work.  Glad to hear some-one has done it and it works.

My friend who did the PZT for me might be able to do it.

Why on earth don't they put 3 screws in in the first place!!!!! :!

Carole


RobertM

Apart from needing more hours you have to fix those stars bottom left but if you want everything orthogonal then consider threading the imaging train together.  Another solution is to use high quality adaptors since they will fit tighter and mean the two screws will lock it in place.  I wouldn't personally use three screws in a focuser as that may not lock the push fit adaptor in place securely.

Robert

Carole

Quoteconsider threading the imaging train together
Not quite sure I know what this means Robert, unless you are referring to the system where the Skywatcher reducer screws to the drawtube, and I don't have that type of reducer.

I cannot see any way of fixing the stars other than making it orthogonal since everywhere else in the image the stars are nice and round, and the spacing is correct, so this is the only thing I assume is causing it. 

Some-one suggested getting one of these, but it's typical that some of my fittings are T2 and this is M48, and is probably going to mess up my spacings.

http://www.altairastro.com/product.php?productid=16549&cat=315&page=1

So I am pondering on this at the moment.

Carole


RobertM

That's only good if your ccd isn't orthogonal to the camera axis.  Since it has a 2" fitting, if you rotate the camera push fit part of the imaging train then it'll be even further out - the adjustment will be for one position of the camera only (or within a few degrees of that position).  If you've tried your camera with nosepiece in another scope and it's ok then that'll be a waste of money.  Really the only way I've found of checking the camera without setting up a test rig is to use a good scope as reference. 

Does that help
Robert

Carole

#12
QuoteDoes that help
Thanks Robert.  Well it tells me that the above might not be the solution.  

I get the same thing with my DSLR and the same scope so this tells me it's too coincidental to be the sensor of both cameras and must be to do with the orthogonality (is that a word??) of the optics.  This is with my new WOZS71.  

I've just taken a look at my ED120 and ED80 subs and these seem to be OK with both the Atik and DSLR, so looks like it is the optics of the WO scope.  But even the Earlier images with the WO scope don't look as bad as I am getting now, so really confused and not sure what to do about it.

Carole