Melotte 15!

Nebulas are a truly fascinating, awe inspiring creation of our universe. Bursting with such rich, vibrant colours, dominating the night sky above us. It's in the darkness we find new light, beauty is above us in every direction.

This is my first SHO image, as well as a first light for my 200pds and EQ6 R Pro. So far I have to say this is a dream of a mount! And the scope is easy to collimate, and for the price you cannot beat it.

Astronomik Ha: 59x300" (Gain 139, Offset 21)Baader OIII: 46x300" (Gain 139, Offset 21)Baader SII: 49x180" (Gain 139, Offset 21)

Total Integration: 11.2 Hours

EQ6 R Pro

Skywatcher 200pds

ASI 1600mm Pro

Processing this image was a big task for me, as I've never done SHO narrowband before, I had to do some research. Took me around about 5 hours total, not including the time spent stacking each filter.

First off I took the raw Ha, OIII and SII subframes into Deep Sky Stacker and stacked them there. Once done, I took them into Pixinsight for post-processing. In the linear stage (before stretching the files) I star aligned the images. I deconvoluted all the stacks, using a Dynamic PSF and the decon tool in PX. After this I did some noise reduction using the multiscale linear noise reduction tool, along with a linear mask. Now I stretched each image, making sure the background levels were the same using the levels tool. Now in the non-linear stage, I used Starnet++ in order to remove the stars - doing this makes colour manipulation easier without having to worry about the stars being blown out or discoloured. Now, with the three starless images, I combined them using the LRGB tool, SII in Red, Ha in Green and OIII in Blue. This outputed a rather horrid looking, green bias image. The next process was a neat trick I learnt from Dylan O'Donnell. I saved the green image, and also saved a version with the green removed by using the SCNR tool. With these two images, I took them into Photoshop and layered them on top of one another. Doing this helps to eliviate the BiColour look it has when removing the green completely. From here I spent a while messing around with selective colour in order to get the colours how I like - I was after a bright blue and golden yellows. After this, I used some actions in Photoshop, including deep space de noise and colour blotch reduction to get rid of some of the remaining noise. With this done, it was time to do some sharpening and curve adjustments to further boost the clarity and contrast. After this I added back the Ha stars, using a luminosity blend with the processed Ha layer on top of the starless SHO colour image. From here it was just the case of some final adjustments in Pixinsight, messing with the colours some more and final touches as well as cropping the image to the region on interest.