Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: MarkS on Jan 29, 2017, 22:15:51

Title: M78 Revisited
Post by: MarkS on Jan 29, 2017, 22:15:51
I've done M78 once before but wasn't happy with the result.  This one is better framed, sitting inside Barnard's Loop and it shows the dust better.

Shot using H-alpha enabled Sony A7S on Tak Epsilon.  340x30sec at ISO 10000.

(http://www.markshelley.co.uk/Astronomy/2017/m78_20170126_small.jpg)

There's also quite a nice open cluster (NGC 2112) sitting on Barnard's Loop.

Larger version here:
http://www.markshelley.co.uk/Astronomy/2017/m78_20170126.jpg

Mark
Title: Re: M78 Revisited
Post by: Carole on Jan 30, 2017, 09:59:48
That is looking great Mark, lovely colour, especially with Barnard's loop and you've managed to get the dark nebula showing really well. 

I bet you are pleased with it.

This is my next target to finish once I can get imaging again, hope it will still be in the sky by then, I did not manage to get much colour when I have tried it before, probably because it was pre-dawn.

Carole
Title: Re: M78 Revisited
Post by: Fay on Jan 30, 2017, 17:28:37
Very nice Mark, open cluster a surprise!

Fay
Title: Re: M78 Revisited
Post by: MarkS on Jan 30, 2017, 21:28:21
Here's another version of the same data that demonstrates the power of Bayer Drizzle:

(http://www.markshelley.co.uk/Astronomy/2017/m78experiment_small.jpg)

Full size version is here:  http://www.markshelley.co.uk/Astronomy/2017/m78experiment.jpg  (make sure you view at full scale)

The full size version is actually 133% of the original camera scale.  But although I've increased the scale, the stars are still looking very tight.  Obviously the image appears a lot noisier because there isn't quite enough data to support that large scale.  But once I've improved my noise reduction techniques it could be quite a credible image in it's own right.  Two images for the price of one!  I would guess that presented with both images, no-one would guess it was exactly the same dataset that was used for both - they look as if they have come from two entirely different imaging rigs.

I've also given this second image a subtle but worthwhile dose of PixInsight HDRMultiScaleTransform to enhance the detail in the brighter areas.

Mark
Title: Re: M78 Revisited
Post by: JohnP on Jan 31, 2017, 08:07:39
Very nice Mark. I actually think 2nd (larger) image looks smoother despite up-scaling... John
Title: Re: M78 Revisited
Post by: MarkS on Feb 01, 2017, 12:48:29
The clever thing is that I didn't upscale anything.  The drizzle happily produces an image twice the size of the original and I then downscaled it by 2/3.

Mark