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Gallery / Cocoon Nebula in HaRGB
« on: 2019 January 06 13:50:07 »
IC5146 - Cocoon Nebula in HaRGB

Located in the constellation of Cygnus lies the Cocoon Nebula (IC5146), this nebula is an emission nebula. This is my first ever attempt to image this target, again like previous targets I am limited to around 2.5 hours per night on this target due to trees and the house getting in the way.
Image Details:
56x150S in R
56x150S in G
66x150S in B
101x300S in Ha

Acquisition Dates: Sept. 25, 2018,  Sept. 27, 2018,  Sept. 29, 2018,  Oct. 20, 2018,  Oct. 22, 2018,  Oct. 26, 2018,  Oct. 28, 2018,  Oct. 29, 2018,  Nov. 14, 2018,  Nov. 17, 2018,  Nov. 18, 2018,  Nov. 30, 2018,  Dec. 7, 2018,  Dec. 9, 2018,  Dec. 12, 2018,  Dec. 13, 2018,  Dec. 27, 2018,  Jan. 4, 2019
All frames had 101 Darks and Flats applied, the Ha layer was blended using the new NBRGB Script in PixInsight 1.8.6, the more zoomed in picture is of the same data but with a 2x drizzle applied then cropped
Equipment Details:
Imaging Camera: Qhyccd 183M Mono ColdMOS Camera at -20C
Imaging Scope: Sky-Watcher Quattro 8" F4 Imaging Newtonian
Guide Camera: Qhyccd QHY5L-II
Guide Scope: Sky-Watcher Finder Scope
Mount: Sky-Watcher EQ8 Pro
Focuser: Primalucelab ROBO Focuser
FIlterwheel: Starlight Xpress Ltd 7x36mm EFW
Filters: Baader Planetarium RGB and Ha
Power and USB Control: Pegasus Astro USB Ultimate Hub Pro
Acquisition Software: Main-Sequence Software Inc. Sequence Generator Pro
Processing Software: PixInsight 1.8.6

Flickr Link:

AstroBin Link:

Thanks for looking

I have a Core i9 10 Core / 20 Thread CPU, I have defined in my config that there should only ever be 18 threads (In order to leave some compute available for other running applications), however I have noticed this morning when performing an image registration using the star alignment tool that it reported "22 Threads" which I find a little odd considering

1. I do not have 11 Cores/ 22 Thread CPU
2. I have limited PI to only perform using 18 threads

Everything else seems to run fine such as Calibration, Integration etc they are all limited to 18 threads as expected.

What information would you need, pretty re-producible

General / Benchmarks
« on: 2018 December 31 12:08:57 »
Hi All

I wondered if everyone runs the benchmark at all?  Maybe we should all post our benchmark results and share any best practices?

The Official PixInsight Benchmark version 1.0
Copyright (C) 2014-2015 Pleiades Astrophoto. All Rights Reserved.

Benchmark version ...... 1.00.08
Input checksum ......... 2cd72b67e12fff2812ef5b5da054ab2a70a25e23
Serial number .......... M70B7J5Z775H5ACCBCOMZRGZTL1IWF2T

CPU Identification
CPU vendor ............. GenuineIntel
CPU model .............. Intel(R) Core(TM) i9-7900X CPU @ 3.30GHz

System Information
Platform ............... Windows
Operating system ....... Microsoft Windows 10 Pro
Core version ........... PixInsight Core (x64)
Logical processors ..... 20
Total memory size ...... 31.706 GiB

Execution Times
Total time ............. 00:55.99
CPU time ............... 00:38.20
Swap time .............. 00:17.75
Swap transfer rate ..... 933.753 MiB/s

Performance Indices
Total performance ...... 8401
CPU performance ........ 9909
Swap performance ....... 5172



I am a bit lost here now, I have followed the LightVortex steps on creating a SuperBIAS from 999 BIAS frames, however I am a little concerned about the results, the first two images show the MasterBIAS on the left and the SuperBIAS on the right, the 2nd image shows the resulting MasterDark after calibrating all the dark frames against the MasterBIAS (Left) and SuperBIAS (Right), all images have had an STF applied.

The third image is a MasterDark with no BIAS deducted which to me looks a lot more "Normal"

Why do my MasterDarks look so bad when the Master/SuperBIAS has been deducted?  Does anyone have an example of their MasterDark when BIAS has been subtracted during the calibration of the darks?

General / Confusion about Darks / Flats / BIas / Dark Flats
« on: 2018 December 30 14:16:28 »
It's that time of year again when I build my new Calibration Library (Since moving to Unity Gain as well), so my Calibration Frames are as follows

1. 101xDarks for Each Exposure Length (90, 150, 300 and 600 Seconds) - Used to create Master Dark for each exposure length
2. 101xFlat frames taken as same Gain/Offset as Darks and Lights for each colour filter
3. 3500+ BIAS Frames with same Gain/Offset as Flats, Darks and Lights

Now I have always done the following
Calibrated Flats against Master/SuperBIAS since my flat frames are sub 4 seconds (LRGB are all sub second) to create Master Flat for each filter
Combined all Darks to create Master Dark for each exposure length (Not subtracting BIAS)
When Calibrating Lights, only the Master Flat and Master Dark are subtracted (Since Darks contain BIAS Signal)

However, I am reading that I should be deducting the BIAS from the darks and then in the Light frame calibration I should be deducting the Master/SuperBIAS from the lights, so the question is, should I only be doing this is I am scaling my Darks?


Hi All

I remember this time last year having major problems processing M81/M82 but that was with my 8.3mpx CCD images with a C80ED, now I am using a faster focal ratio and a 20mpx camera, I am having a challenge using HDRMT as it keeps blowing out the core, so should I be masking out the core early on in the processing cycle?


Hi All

I've spent quite a bit of time on PixInsight over the past year, but M81 / M82 is really causing me to loose what hair I have left on my head, I can't seem to minimise the background noise without it getting blotchy, this is what I tried so far

1. Performed a DBE on LUM Image
2. Auto STF on LUM image
3. Clone out to secondary image
4. Apply Auto STF to HT and apply to Clone
5. Use Clone as Inverted Mask on LUM image

Now I have tried ACDNR, MLT, MMT all with mixed results, attached is my Luminance Image, I have an RGB and HA image to process as well, but I am starting with the Luminance image and maybe I could learn where I am clearly going wrong

The Fits file can be downloaded from here

Looking to learn :)


General / 32 Bit v 16 Bit, which one and when?
« on: 2018 February 23 12:41:25 »
Hi All

I understand the need to leave your calibration masters etc in 32 Bit Floating, but what abount once you have combined channels etc?  The reason I ask is a single RGB image is now taking up almost 1GB of space, and I get quite frequent "Hangs" in PI when doing things like MMT Previews etc, especially when using Drizzle!

So once the image is in RGB, can it be reduced to 16Bit for Processing?


Wish List / GPU Utilization
« on: 2018 February 20 07:59:06 »
Haven't come across a thread suggesting this, so forgive me if there is one.

With GPU's having a lot more cores/resources is there a plan to offload some functions like DrizzleIntegration which are pretty...let's face it...intense tasks for even the later CPUs, especially with Camera sizes getting bigger also, it makes sense to leverage the GPU, or have an option to leverage the GPU

Hi All

I am reading a lot of contradictory posts on here as well as the PixInsight Tutorials.

I am using the QHY183M Camera, and I am just building my Darks, Bias and Flats, I have created my SuperBIAS already.

Now I know I have to apply the Super BIAS to my Dark Frames before Integration to create my Master Darks, however for the flats, since my exposure for flats are all below 2 seconds, do I really need to subtract darks from my flats?  Surely I just subtract the SuperBIAS from my flats no?

Also should all my masters be saved in 32Bit Floating?

Many thanks all

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