Praying Ghost VDB141 and Iris Nebula NGC 7023 LRGB from les Granges

[Carole]

With Olly's widefield camera I was able to get both of these in one frame.
Processing on my own.

Atik11000
Takahashi FSQ106N
Mount: Takahashi EM200
Baader filters

Luminance 12 x 900
Red 4 x 600
Green 3 x 600
Blue 6 x 600
But short on the colour, but got what I could.

Total 5 hrs 10m

Full frame:
http://cdn.astrobin.com/images/f46fdb53-4ab9-4b6b-8011-3a8888bc6d49.png



Carole

[Fay]

another good one Carole. at least it was worthwhile going!

Fay

[Carole]

Thanks Fay, yes we had clear skies every night except 1 which obscured the South, so some of my targets were unreachable and I had to choose something else.  Up until 2.30 - 4am every night for 6 nights in a row was rather exhausting.  

Carole

[Carole]

Crop of the Ghost

[Carole]

Crop of Iris

[MarkS]

Another great image Carole!

Lots of dusty bits and good star colours.  You've got good colour in the Iris Nebula itself.

You must be really pleased with your trip to France!

Mark

[Carole]

Thanks Mark,

You must be really pleased with your trip to France!

Yes very.  Just goes to show what we are up against in the UK. 

Carole

[Ivor]

Excellent shot again, is there any more to look forward to?

[JohnP]

looks nice Carole - Actually still looks a bit noisy on full frame (which suprised me given location) but maybe due to lack of colour like you say. Also on full frame there are tons of light blue individual pixels - any ideas what has caused these?

A very nice image though - you must be haps - amazing what good sky & expensive kit can get you..

John

[Carole]

Thanks every-one:

is there any more to look forward to?

I also did M16 Ha only, and M8/M20 but still to process the latter.  I am having the same problem with the M16 Ha as I did with the Helix Ha, DSS is not stacking it properly.  Managed to do one night's data in nebulosity, but still grappling with it.  Not attempted M8/M20 yet except for a quicky when I was in France, and there is rather a lot going on here ATM so might not be until tomorrow.  

on full frame there are tons of light blue individual pixels - any ideas what has caused these?

I think this might be the remains of hot pixels which DSS did not process out properly.  Always a bit nervous about setting this too aggressively in DSS as it can produce stars with holes in them.  

Might try a different stacking programme.

Carole

[Mike]

Did you not dither between frames as that will get rid of hot pixels?

[Carole]

Using Olly's set up and he didn't mention having dithering Mike. 

As it was I had a lot of new technqiues, hardware and software to get my head around, plus some of his kit stopping working and we had to change guide cameras, and computers in the middle of a run (in the dark), but must admit it didn't cross my mind.  We were using Artemis for capture which I don't think has a facility for dithering, if any-one knows better, please let me know as that is one thing I do use at home.

Carole

[MarkS]

You used Artemis for camera control. 

What did you use for guiding?

[Carole]

At the beginning I think we were using Astroart for guiding, but then the lodestar was not working properly and so we had to change guide cameras and laptops (because of drivers), and changed to PHD and I can't remember exactly when that happened. 

I know how to dither with PHD in APT, but doesn't the capture programme have to have some sort of connection to PHD - if there is such a thing in Nebulosity (yes capture Mark), then I haven't yet found it.

Carole

[MarkS]

That's right - the capture program has to be written to connect to PHD to do the dithering.  But it is really easy to do - I know because I wrote a dithering connection to PHD from the Canon capture program I wrote.

So if they wanted to program up a connection from Artemis to PHD it would actually be straightforward.  The results that you obtained from France show that dithering is definitely necessary (at least for the Atik 11000) because there are obvious hot pixels when viewed full size.  Lots of short trains of R G B pixels when the images are aligned.  It could be that the dark (if a dark was used) wasn't completely calibrated but in any case dithering would help enormously.