Carina Nebula Untracked

[XENOBLADE2 (Shiv)]

Carina Nebula Mega Project
~3hrs intergration
200mm
f/5.6 and f/2.8
iso 3200
Untracked
Bortle 6

This project started in March and finished in mid-April.
Stacked in WBPP, Processed in Pixinsight, Photoshop and GraXpert.
128gb of raw images+calibration frames and 37 hours of stacking time.
This is the most I could get and I'm very pleased with it. Would've loved to get more f/2.8 data but stacking artifacts were already quite bad hence I called it there. |

[Dave882 (David)]

Nice result Shiv! Sounds like a huge project well done on getting it across the line!
If you’re using PI and have plenty of data, I reckon using the GENERALISED HYPERBOLIC STRETCH script may really help bring out the faint regions while preserving detail in the bright areas too. It’s a free add on and really easy to use

[XENOBLADE2 (Shiv)]

Originally Posted by Dave882

Nice result Shiv! Sounds like a huge project well done on getting it across the line!
If you’re using PI and have plenty of data, I reckon using the GENERALISED HYPERBOLIC STRETCH script may really help bring out the faint regions while preserving detail in the bright areas too. It’s a free add on and really easy to use

Hey David,
This definitely was a very big project, it was ~5000x2s subs on an unmodded DSLR.
When processing this image, I made several processes using GHS. A person on a discord server made a script called "iHDR" (iterativeHDR) which preserved the bright regions (Keyhole region) that I was struggling to prevent from getting overstretched. I found it did a really good job hence I used it for this image. If you would like, I can send over the repository link for you to try out.

[Dave882 (David)]

Originally Posted by XENOBLADE2

Hey David,
This definitely was a very big project, it was ~5000x2s subs on an unmodded DSLR.
When processing this image, I made several processes using GHS. A person on a discord server made a script called "iHDR" (iterativeHDR) which preserved the bright regions (Keyhole region) that I was struggling to prevent from getting overstretched. I found it did a really good job hence I used it for this image. If you would like, I can send over the repository link for you to try out.

Hi shiv yeah I’d love to look at that thanks mate.
2sec subs!! No wonder it was so huge. Perhaps a more economical way to undertake a project like this would be to to a bunch of longer exposure shots and then some shorter exposures for the core?

[XENOBLADE2 (Shiv)]

Originally Posted by Dave882

Hi shiv yeah I’d love to look at that thanks mate.
2sec subs!! No wonder it was so huge. Perhaps a more economical way to undertake a project like this would be to to a bunch of longer exposure shots and then some shorter exposures for the core?

Originally my plan wasn't to create a HDR image, it was to just get 1 big image. In theory I probably could've done a hdr using the data at f/5.6 and use the f2 data for main structure but didn't really cross my mind and the fact I'm restricted to 2 second subs is quite limiting.

Here is the instructions and repository link for iHDR:

Use this tool to reveal faint structure in the image (i.e. IFN, galaxy halo, Milky Way dust) while preserving bright objects (galaxy cores, bright nebulae, etc).

To install the script:
In PixInsight, go to Resources --> Updates --> Manage Repositories
Click the "Add" button on the bottom left of the popup
Enter the repository https://astrouri.com/pixinsight/scripts/iHDR/ and click "OK"
Close the window and click on Resources --> Updates --> Check For Updates
Click "Apply" on the bottom right of the popup and restart PixInsight
The script should appear under Scripts --> Sketchpad --> iHDR

Temporary Note: since Juan has not approved my developer certificate yet, you will get a warning about the script being potentially unsafe when installing. It is perfectly safe, trust me :wholesome~2:

To use the script, follow these instructions:
- Stretch the image such that the brightest areas (such as the galaxy or nebula cores) are at the intensity you want them to be in the final image.
- Select the appropriate preset: Low HDR, Medium HDR, or High HDR
For most use cases, Medium HDR will work fine, but experimentation is encouraged.
- If you want to go beyond the presets:
- Increasing Mask Strength will increase the strength of the preservation, and vice versa.
- Increasing Stretch Iterations will increase the amount of times the stretch is applied to the image.
- Increasing Stretch Intensity will increase the amount the image is stretched per iteration.
- Increasing Layer Preservation will lead to greater contrast, but will protect smaller objects less.
- After you select the appropriate settings, apply the script.
Depending on the dynamic range of your target, it is likely you will need to run the script multiple times. Alternatively, you could increase the repetitions option.