IC2944, The running chicken nebula
(30 March 2014, Sutherland, South Africa)
IC2944, The Running Chicken Nebula, is located in the constellation Centaurus. To image this I used the 8” Orion Astrograph and Canon 60Da. The light gathering capabilities of the scope at F/3,9 is a pleasure to work with, but left me with a very rich star field.
(See the higher resolution here: http://www.astrobin.com/full/102682/0/)
I have revisited my edit of this target for about 2 months, trying various star reduction techniques but never being happy with the artefacts left on the stars – I’m finally (relatively) happy with the edit.
Morphological Transformation used in this image.
I generally refer to this tutorial when doing a MT in PI. It’s work well for most of my images and I highly recommend you try this method 1st.
http://www.deepskycolors.com/archive/2011/09/08/star-size-reduction-via-Morphological-.html By Rogelio Bernal Andreo
It involves cloning your original, applying HDRmultiscale and then creating a star mask from that, with the mask contours of the small to mid sized stars. This mask is then applied to the original and from the MT process, the Morphological Selection is selected. (I think due to this offering a mix of erosion and dilation. But please try this tutorial on your images 1st.
Sadly for IC2944 it left bad artefacts on the stars, regardless of various mask options I applied. I spent a fair amount of time working with various masks and MT options – but in the end I used a straight forward Erosion, 1 iteration with the amount at roughly 40 / and then again towards the end when I neared completion with a lower amount.
What I did do tho is when I applied my stretch to non-linear, I did not do it too aggressively. I had an initial one, and then used a series of star masks to ensure I protect more stars and rather stretch the areas containing nebulosity.
Stacked / calibrated image prior to processing
… Hopes this helps someone.
About the setup:
This was taken on our March/April 2014 AstroTrip to Sutherland in the Northern Cape in South Africa. For the trip we were imaging on 3 complete setups (Celestron CGem DX / Advanced VX / CG5) with the Orion 8” Astrograph and a Officina Stellare HiperAPO. Splitting 3 mounts/imaging opportunities between 2 astrophotographers isn’t easy, Cory and I worked to a schedule to ensure we had equal opportunity with both scopes, our newly acquired QSI CCD and a few of our wide field lenses.
Sutherland is the home of SALT (Southern African Large Telescope), naturally a very dark location in the Karoo (Semi-desert) with ideal imaging conditions. Cold, dark and clear…
As with anything is astrophotography, nothing comes easy. I’ve been trying complete this edit for 2 months getting my star better. Here’s what attempt 1 looked like:
Imaging Info:
Orion 8” Astrograph
Baader MPCC
Canon60Da
SSAG
40x 300sec iso800
3,3hrs
Acquired: Nebulosity
Processing:Pix Insight & PhotoShop
Guiding: PHD2
100 bias
30 flats
30 darks
The above is my second attempt at this target. Below you’ll find the 1st attempt, imaged from my home in Johannesburg February 2013. (61 x 60 sec @ ISO 400 / CGemDX & Officina Stellare APO)
