Getting There

Image Critiques
1

OrionNebula_NPN.jpg
OrionNebula_NPN.jpg1500×1114 1.2 MB

Critique Style Requested: Standard

The photographer is looking for generalized feedback about the aesthetic and technical qualities of their image.

Description

On November 23 I went out to photograph Orion again. At the end of the session I decided to zoom in on just the Orion Nebula. I took 7 frames at 1 minute each and 3 dark frames. I do not know how I managed to squeak out the detail that I did. I processed the files in Siril and Starnet++ and then in PS and then back in SIril to recombine the starless and stars images. I am going to try this image again, with more subframes and try to get more detail in the core, I think I am getting there.

Specific Feedback

Any feedback is appreciated.

In particular, do the colors work?

Technical Details

Nikon D850, Nikon 400mm f/5.6 MF lens, set at f5.6, 1 min, ISO 1600 - 7 frames, and 3 dark frames.

Processed in Siril then Stranet++ to separate the nebula from the star field. Stretched the nebula in Siril, and used a new script that performs some kind of HDR on and image. That took some time repeating that process over and over changing parameters until I got something that I thought was saving the core as best as I could. I also used another script called Graxpert-AI to denoise the image and it worked very well. Then I brought it into PS to get the colors looking somewhat right based on viewing many other images of the Orion Nebula. Colors in Astro images are so subjective sometimes.

Critique Template

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Vision and Purpose:
Conceptual:
Emotional Impact and Mood:
Composition:
Balance and Visual Weight:
Depth and Dimension:
Color:
Lighting:
Processing:
Technical:

2

I think you’re getting there, too!! Managing the brightness of the Trapezium area is one of the holy grails of astro processing. It sounds like the Siril “HDR” script is similar to HDRWaveletTransform in PixInsight, which is devilishly difficult to use. There is also a process to combine different exposures – HDRComposition. But the newer Transform is more than adequate.

With the need to tame brights causing more challenges in the darker regions, more acquisition time is your best friend. Something more like 7 hours would be ideal. At f/5.6, 1 min exposures are probably OK, but if there is any tracking issue, 30 sec should also be good for the dimmer areas with enough acquisition time. It has about become my default.

I’d love to get a clear dark night while Orion is available. My data on it predates my autofocuser. And it’s been like nuclear winter up here with thule fog.

3

Nice image of M42 and NGC 1977. The colors look nice, and you picked up a lot of the brighter part of the nebula. What works well for me is a very short 20 second exposure to resolve the core. Then create a layer in Photoshop to blend the 2 together. Also, try bringing up the shadows just a bit to pick up more of the other nebula around Orion. Nice image.