M42 - The Great Orion Nebula

I've been meaning to try out Astro Pixel Processor (APP) for a while now with a view to buying it as my main astro processing software, but I've not had any image data which I regarded as being worthy of extensive processing until now.

Following my successful Team Viewer based remote setup using a long weatherproof network cable from my house into to my garden, I can now control my laptop for finding targets, controlling my mount and capturing image data from the warmth and comfort of being indoors.  I use Carte du Ciel to locate the target and Astro Photography Tool (APT) to plate-solve the image and centralise it in the field of view.

The first target I chose was M42, the Orion Nebula, my thoughts being that if I can't get decent images of this then I might as well give up.  I setup an exposure plan in APT to capture a range of exposures from 10 seconds to 120 seconds, in order to have correctly exposed shots of both the core and the outer nebulosity.  I also took some dark frames with the same exposure and corresponding bias frames, but no flats.  Then I loaded them all into APP.

I'm not going to go into the processing details here as I'm still on the steep learning curve of this sophisticated software, but APP calibrates the main images (lights) with darks and bias frames, before analysing the stars it finds, aligning or registering the images, normalising them and finally stacking or integrating them into a single image file.  All this is done automatically with no intervention if the default values are used.

Following integration, the image can be stretched to widen the dynamic range and reveal details unseen in the initial images and various other adjustments made before being saved.  Although the image APP produces is pretty good, it is normal to process it further in a graphics package such as PhotoShop or GIMP to tease out even more subtle detail. And this is what I have done here.  

So these images all stem from the same set of data captured in APT and calibrated and stacked in APP.  You can play around with the colours and fine detail for ever and it's difficult to know when to stop.  Different techniques produce different colours and effects, it's up to the viewer to decide which they like best.  To some extent it's impossible to know what the true colours are as we can't actually see them with the naked eye.