SH2-155, The Cave nebula

[emyliano2000]

Hello again. 

Last night I was up a bit later than usual to try and finish my cave nebula. 

I think there's a lot I need to learn on using the noise reduction properly, on reducing the big fat stars properly and controlling the halos. 

Looks good when I look at it from far away or on my phone 😂 but when you zoom in it's 😱. Am I crazy? 

I would really appreciate if you guys would tell me when in the process you use the noise reduction and what noise reduction techniques you use. 

Thanks

Emil 

Edited October 20, 2019 by emyliano2000

[emyliano2000]

I have pixinsight that I can use but have no clue on how to use masks. I also have photoshop (Noel Carboni's astronomy tools, Annie's action pack, Noise ninja, Nick's filter pack with Dfine for noise reduction) where I do most of my processing. 

Edited October 18, 2019 by emyliano2000

[don4l]

I tried this last year and I never got a decent result.  You have done far, far better.

It does look noisy when displayed at full resolution, but the image is coming up at over 5000 pixels wide.  Does your camera really have this many pixels, or has the image been upsampled somewhere along the way?

[Hughsie]

I use Pixinsight too and use MLT before stretching and then TGVDenoise afterwards if still needed. There are some great tutorials on https://www.lightvortexastronomy.com/tutorials.html which will provide some insight into Pixinsight.

 

John

[emyliano2000]

4 minutes ago, don4l said:

I tried this last year and I never got a decent result.  You have done far, far better.

It does look noisy when displayed at full resolution, but the image is coming up at over 5000 pixels wide.  Does your camera really have this many pixels, or has the image been upsampled somewhere along the way?

It is indeed 5000 pixels wide. The qhy183m is a 20mp camera. I should probably bin the imaged 2x2 in pixinsight because unbinned the resolution of 0.72 "/pixel is a bit high for nebulas. 

Emil. 

[jjosefsen]

Hi Emil,

I use a combination of TGVDenoise and MMT in PixInsight on the individual masters while they are linear, and before combining to RGB. Works quite well!

Extensive masking is used - so TGVDenoise primarily targets high signal areas (bright) and MMT targets low signal areas (dark). Don't go too crazy while linear, the final noise reduction will be done after the image has been stretched, and I also use TGVDenoise there.

[emyliano2000]

Thanks. I need to have a look at those light vortex tutorials.