Milky way - One Shot Image - Take II

[Alejandro Tombolini]

From one of the best skyes of Argentina, in San Rafael, province of Mendoza.

I was in a star party and only had with me the camera and a little tripode, then, I tried a cuople of image.
This is a single image unguied, and ofcourse the stars are lines, but when resampled is almost imperseptible.
Canon 5DIII - ISO 12800 - Exposure: 30 seconds - F/D 6,44 - Focal Length 24 mm

As I do not have masters for this ISO, I integrated 50 bias of ISO 6400 to generate the MaserBias and use a single 20 minutes darks to calibrate as I have a line that need to be corrected with a dark.

Debayer of te calibrated image and correct some Cold and Hot pixels

There were needed two DBE to correct the gradients. (I do not use flats for calibration)

Generate a preview representative of the background to be used as Reference Image in Background Neutralization Tool

Generate a preview of the main part of the galaxy to be used as Reference Image for White Reference in Color Calibration and the same preview as before to be used as Reference Image for Background Reference

Now the key cuestion here is generate a mask that allow to process the sky without afecting the mountains and viceversa.
For that I clone the image and apply consecutivelly Morfological transformations and smoothnees with ATWT until have a good diferenciation between sky and mountains that allow range mask to generate what I am looking for.

Now I will work protecting the mountains. First apply the formula to elimiante darks holes.

Transfer STF to the HT tool and apply

Noise reducction: to green

Chrominance noise reduction in big scales

Saturation with CurvesTransformation

Noise reduction in one pixel layer using MultiscaleMedianTransform tool

Chrominance nose reduction in  layers from two to eight pixels

A little more contrast with ATWT

Curves to correct colors (a and b)

Exponential transformation to smoothnees the background

Now I need a more located chrominance noise reduction, for that I will generate a mask that protect at the same time the mountains and the brigh part of the sky.

Extract Luminance, invert and apply curves and ATWT to smoth a little

Then, with PixelMath add the luminance and the previous RangeMask

Now apply chrominance noise reduction in the background

Protecting now the sky with the first range mask, apply HT to the mountains (Transfer the STF to the HT tool)

Reduce red in the sky protecting the mountains.

Noise reduction to smooth the background using ACDNR

Rotate 90? Counter-Clockwise and resample

Add signature

Final image:

Saludos, Alejandro.

 

[Jules]

Thats a gorgeous image Alejandro.

I have been thinking for a while to get a SLR for this sort of imagery. Its spectacular stuff.

Regards

Julian

 

[chris_todd]

An awesome image and excellent tutorial!  Thanks again, Alejandro!

 

[cs_pixinsight]

Alejandro, I'm fond of this type of astrophotography (the reason I started AP) and this really reinforces that.  I use an Astrotrac with my DSLR and have just started putting together a 10 image mosaic of the Milky Way.  This tutorial will be a terrific asset in processing those images and serve as further inspiration in what can be achieved.

Craig

 

[Alejandro Tombolini]

Thank you all for the comments! Good to know that it can be helpful.

Craig, that mosaic sounds promising!

Saludos. Alejandro.

 

[talbotj]

Alejandro,

Excellent tutorial.  Thank you.

Jon Talbot

 

[Alejandro Tombolini]

Thank you Jon!!!
Saludos, Alejandro

 

[lekatsas]

Hi Alejandro,

Glorious image and extremely helpful tutorial. Amazing what you can do with one unguided shot.

Tel

 

[boris sputnik]

Absolutely Awesome !!!  Congratulations !

 

[astropixel]

Alejandro. What an absolute delight. I want to follow this through with one of my own images, step by step. Thank you for sharing this.

 

[jeffweiss9]

Alejandro-
Beautiful Milky Way shot and great tutorial.
Thinking of trying some shots in this direction.
Thanks,
-Jeff

 

[KGee]

From one of the best skyes of Argentina, in San Rafael, province of Mendoza.

I was in a star party and only had with me the camera and a little tripode, then, I tried a cuople of image.
This is a single image unguied, and ofcourse the stars are lines, but when resampled is almost imperseptible.
Canon 5DIII - ISO 12800 - Exposure: 30 seconds - F/D 6,44 - Focal Length 24 mm

As I do not have masters for this ISO, I integrated 50 bias of ISO 6400 to generate the MaserBias and use a single 20 minutes darks to calibrate as I have a line that need to be corrected with a dark.

Debayer of te calibrated image and correct some Cold and Hot pixels

There were needed two DBE to correct the gradients. (I do not use flats for calibration)

Generate a preview representative of the background to be used as Reference Image in Background Neutralization Tool

Generate a preview of the main part of the galaxy to be used as Reference Image for White Reference in Color Calibration and the same preview as before to be used as Reference Image for Background Reference

Now the key cuestion here is generate a mask that allow to process the sky without afecting the mountains and viceversa.
For that I clone the image and apply consecutivelly Morfological transformations and smoothnees with ATWT until have a good diferenciation between sky and mountains that allow range mask to generate what I am looking for.

Now I will work protecting the mountains. First apply the formula to elimiante darks holes.

Transfer STF to the HT tool and apply

Noise reducction: to green

Chrominance noise reduction in big scales

Saturation with CurvesTransformation

Noise reduction in one pixel layer using MultiscaleMedianTransform tool

Chrominance nose reduction in layers from two to eight pixels

A little more contrast with ATWT

Curves to correct colors (a and b)

Exponential transformation to smoothnees the background

Now I need a more located chrominance noise reduction, for that I will generate a mask that protect at the same time the mountains and the brigh part of the sky.

Extract Luminance, invert and apply curves and ATWT to smoth a little

Then, with PixelMath add the luminance and the previous RangeMask

Now apply chrominance noise reduction in the background

Protecting now the sky with the first range mask, apply HT to the mountains (Transfer the STF to the HT tool)

Reduce red in the sky protecting the mountains.

Noise reduction to smooth the background using ACDNR

Rotate 90? Counter-Clockwise and resample

Add signature

Final image:

Saludos, Alejandro.

Alejandro, great tutorial and results! I know this is a zillion years old thread, but what newer processes, for noise reduction and other tools you would use in 2024 version. Thanks again for the rundown.