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Old 26-06-2016, 01:50 PM
glend (Glen)
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glend is offline
Join Date: Jun 2013
Location: Lake Macquarie
Posts: 5,635
Ok here is my long sub narrowband version of NGC 6188. This was shot over a couple of weeks, just finished up last night. The last time on this target I used 60" subs and despite alot of them I was scraping data off the noise floor to build an image. While the camera is great at 60" for RGB, for narrowband it really does need around 300 seconds. I think this time it is a significant improvement and better reflects the camera's capability. There were over five hours of 300" subs that went into this image, Ha, OIII, and SII in Hubble Pallet scheme.
Shot with the ASi1600 at -25C, and captured with SGP. Stacked in DSS with Darks and Bias frames but no flats.
Processed in Photoshop CC, and I added a synthetic luminosity layer built of the combined Ha and Oiii greyscale data. It could probably use more adjustment but I will return to that another time. I might mention that the combined layers file when saved in Photoshop CC was 1GB! I am still learning Photoshop so I know it can be better.

I have attached a little down quality thumbnail teaser below, for the real deal you will need to follow the Astrobin links here below. The master file copy in Tiff looks better, but Astrobin only takes jpgs, sorry - too bad there is no where to publish it.

Astrobin large:

Details page with histogram:

Comments welcome, and if you look in my Astrobin Gallery you can see the previous 60" sub image right next to it, it's worth checking out the histograms and comparing.
Attached Thumbnails
Click for full-size image (NGC-6188-ASI1600-300-sec-Unity-small-C.jpg)
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