The Milky Way in Mexico

Home Forums Photo Critique The Milky Way in Mexico

This topic contains 37 replies, has 3 voices, and was last updated by  James Staddon 2 months, 1 week ago.

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  • #18656

    Ezra Morley
    Participant

    I just returned from Mexico not long ago, where we were out in the clear mountain air up close to 8,000 ft high. The sky at night was crystal clear, and I saw the Milky Way like I’ve never seen it before! I was glad that I had brought my wireless remote and that I had access to a tripod!

    Here’s what the camera could see in a single 13 second exposure at ISO 2500 and f/2.8 without any editing.

    EJM_0050-r

    Not bad, but I’ve seen better… πŸ™‚ I could push the exposure in Lightroom and make it “pop” a lot more, but at ISO 2500 you’re going to get a lot of noise if you start pushing the exposure very far.

    Thankfully, I took a lot more than one photo of the same thing. I’m a firm believer in stacking low-light astro images for noise reduction and SNR (signal-to-noise-ratio) improvement. I found that I had taken 18 frames in a row that I could stack to improve the picture.

    So I took my 18 RAW frames, and exported them from Lightroom as 16-bit TIFF files without any adjustments. Then I used a couple of different free, open source software packages to align and stack those ~100MB files into 1 16-bit TIFF file.

    First was the align_image_stack command from the Hugin package. It properly aligned all the stars, but that threw the foreground out of alignment, because the stars were moving slightly between frames. No problem, I’ll fix that after stacking!

    So after all the files were aligned, I used G’MIC and the -average_files command to average the 18 files together into 1 16-bit file.

    Here’s what I get after stacking and aligning:

    averaged-17mm_16bit-r

    Not much difference, eh? πŸ™‚

    But look what happens when we take the original and the stacked file and push the exposure in Lightroom? Ah hah! Now we can see the difference!
    (An 18 frame stack vs. a single frame. Both processed identically in Lightroom)

    Compare Images

    So I took my 16-bit stacked/aligned file back into Lightroom for post processing. Here’s a rough breakdown of the settings I used:

    • Exposure: +2.80
    • Highlights -22
    • Blacks -30
    • Clarity +100
    • Sharpening +50
    • Radius 3.0
    • Masking 100
    • Defringe +5

    Then I exported another 16-bit TIFF and one original frame, and combined the foregrounds in GIMP 2.9.5 so that the blurred foreground from the stacked image doesn’t show.

    Finally, I used exiftool to copy the EXIF data from one of the original files to the finished file.

    And here it is:

    a-1

    Just for interest’s sake, here’s a post I made a long time ago about the Milky Way in Africa.

    Attachments:
    #18856

    Ezra Morley
    Participant

    For those who are interested, here is the batch script that I used for processing a folder full of RAW astro-photos.

    "C:\Program Files\RawTherapee-4.2.539\rawtherapee.exe" -b16 -t -w  -c EJM*.PEF
    "C:\Program Files (x86)\Hugin\bin\align_image_stack.exe" -m -v -a aligned_ EJM_*.tif
    "C:\Program Files\gmic-1.7.5_pre-win64\gmic.exe" -average_files aligned*.tif -o averaged.tif,ushort
    DEL EJM_*.tif
    DEL aligned_*.tif
    "C:\Program Files\exiftool-10.25\exiftool.exe" -TagsFromFile EJM_0076*.PEF averaged.tif
    "C:\Program Files\RawTherapee-4.2.539\rawtherapee.exe" -w averaged.tif
    PAUSE

    If you have RawTherapee installed, just make sure that you have the correct path in the first line of code (replace the words between the quotes, leave the rest of the code intact). You’ll need Hugin for the align_image_stack executable, and you’ll have to make sure that you have the correct path for it as well. GMIC you can get here. Install it, and point the script to your executable. exiftool is for copying the EXIF data from one of the original files to the stacked file. You can download EXIFTool here.

    You’ll also need to change the filename prefixes in the code to your camera’s default. (Usually something like IMG_ or DSC_)

    So the changed code (for the IMG_ prefix) would be:

    "C:\Program Files\RawTherapee-4.2.539\rawtherapee.exe" -b16 -t -w  -c IMG*.PEF
    "C:\Program Files (x86)\Hugin\bin\align_image_stack.exe" -m -v -a aligned_ IMG_*.tif
    "C:\Program Files\gmic-1.7.5_pre-win64\gmic.exe" -average_files aligned*.tif -o averaged.tif,ushort
    DEL IMG_*.tif
    DEL aligned_*.tif
    "C:\Program Files\exiftool-10.25\exiftool.exe" -TagsFromFile IMG_0076*.PEF averaged.tif
    "C:\Program Files\RawTherapee-4.2.539\rawtherapee.exe" -w averaged.tif
    PAUSE

    Make sure you update the filename for exiftool too. My camera shoots .PEF RAW files, yours will likely be either .CRW/CR2 or .NEF You’ll need to change every instance of .PEF to .CRw/CR2 or .NEF. Otherwise you’ll get an error.

    If you have any trouble with it, just ask, and I’ll try to help you out. It took me a long time to learn how to do all this, but the plus side is, now I have some experience! So don’t be afraid to ask!

    #18861

    Austin Vinar
    Participant

    OK, @buddingphotographer I took 10 Raw images of the milky way last night. I have raw therapee, but not hugin. What should be my next step. Thanks!

    #18862

    Ezra Morley
    Participant

    Download Hugin here: http://heanet.dl.sourceforge.net/project/hugin/hugin/hugin-2016.0/HuginSetup_2016.0.0-win32.exe
    Install Hugin. (If you pay attention during installation, you’ll see the path where it’s installed.)

    Next, download GMIC here: http://gmic.eu/files/windows/gmic_win64.zip Unzip the folder and put it somewhere where you can find it. If you’re comfortable with copying folders, you could copy it to your Program Files folder. (Don’t try it if you’re not sure how to do it.)

    If you want to preserve your EXIF data in the final file, then download exiftool here: http://owl.phy.queensu.ca/~phil/exiftool/exiftool-10.25.zip Do the same as you did for GMIC above, unzip the folder to a place you can find.

    • Now copy the paths to RawTherapee Hugin, G’MIC, and exiftool and post them here, and I’ll update the script to work for you. To paste a folder path on the Lenspiration forums, use the code button on either side of the path so that it formats it correctly. Like this: “C:\Program Files\RawTherapee-4.2.539\rawtherapee.exe” Otherwise, the forum HTML code will probably mess it up.
    • I’ll also need the filename of one of your RAW files from the folder you will be processing. (Something like: IMG_4675.CRW) I need the name and the extension)
    #18863

    Austin Vinar
    Participant

    OK, Thanks for the info. I’ll try to work on that. But I have a few questions.
    1. Some of the above is greek to me, so ummm… you mind explaining paths and the code button.
    2. I have G’MIC in GIMP, do I need to download it again?
    3. As the extension for the file name, do you mean the (CR2) at the end, or is it something different.
    Thanks for explaining, I really appreciate it.

    #18864

    Ezra Morley
    Participant

    You’re welcome, hopefully we’ll get it working!

    1. Paths: The series of folders that you have to go through to find the file you’re looking for. πŸ™‚
    2. Yes, you need to download G’MIC again, the GIMP plugin is different from the command line program.
    3. If the last part of your RAW file is CR2, then yes, that’s what I need. I need the whole name though, not just the extension.

    This is a path, you can click on it, highlight it, and copy it to the clipboard, from whence you can paste it into the Lenspiration forum.

    The code button is here:

    Hit “Enter” to make a new line, then hit the Code button one time, then paste your path, and hit the Code button again to close it. You’ll see the instant preview update with a little blue box around the path if you did it right.

    Attachments:
    #18867

    Austin Vinar
    Participant

    Thanks! What about G’MIC?

    #18868

    Austin Vinar
    Participant

    Never mind, I see it now. =))

    #18869

    Austin Vinar
    Participant

    OK, I downloaded G’MIC, and when I open it, all I get is a little black box with some writing in it??? Any tips?

    #18870

    Ezra Morley
    Participant

    Yep, that’s right. It’s a command line window. You’re going to be running this script in the command line prompt.

    Do you have all the paths yet?

    #18884

    Austin Vinar
    Participant

    OK, I’ll try here.
    C:\Program Files\RawTherapee-4.2.1005C:\Program Files (x86)\Hugin\binC:\Users\Jeanette\G'MIC\gmic-1.7.5-win64
    OK, looks like it worked. Thanks for doing this for me!

    P.S. Something to remember, I don’t know the first thing about Hugin or G’MIC, so please explain. Thanks!

    #18906

    Ezra Morley
    Participant

    Ok, good!

    Here’s the code you’ll need to make this work:

    
    SET rt="C:\Program Files\RawTherapee-4.2.1005\rawtherapee.exe"
    SET hugin="C:\Program Files (x86)\Hugin\bin\align_image_stack.exe"
    SET gmic="C:\Users\Jeanette\G'MIC\gmic-1.7.5-win64\gmic.exe"
    
    %rt% -b16 -t -w  -c EJM*.PEF
    %hugin% -m -v -a aligned_ EJM_*.tif
    %gmic% -average_files aligned*.tif -o averaged.tif,ushort
    DEL EJM_*.tif
    DEL aligned_*.tif
    %rt% -w averaged.tif
    

    But before this code will work, I have to have a filename for one of your RAW files. As you can see, my code has “EJM_0076.PEF” in it, which is my RAW filename. I need yours, or the code will fail.

    P.S. The nice thing about this script is that you don’t need to know anything about hugin or G’MIC, those 2 programs do all their work behind the scenes, and you’ll never have to do a thing with them!

    #18909

    Austin Vinar
    Participant

    Oh yes! Here it is. (IMG_0387.CR2)
    So what is my first step… the code doesn’t make sense. =\
    Do I do something with the code?
    I’m kinda lost. =(
    Thanks!

    #18936

    Ezra Morley
    Participant

    Ok, here’s the final code:

    SET rt="C:\Program Files\RawTherapee-4.2.1005\rawtherapee.exe"
    SET hugin="C:\Program Files (x86)\Hugin\bin\align_image_stack.exe"
    SET gmic="C:\Users\Jeanette\G'MIC\gmic-1.7.5-win64\gmic.exe"
    
    %rt% -b16 -t -w  -c IMG*.CR2
    %hugin% -m -v -a aligned_ IMG_*.tif
    %gmic% -average_files aligned*.tif -o averaged.tif,ushort
    DEL IMG_*.tif
    DEL aligned_*.tif
    %rt% -w averaged.tif
    PAUSE
    

    Don’t worry, it won’t be hard! πŸ™‚ Here’s a link to download the script: https://www.dropbox.com/s/7gymxg9j4i2t147/canon-raw-stack-average.bat?dl=1

    Once you’ve downloaded the script, copy it to the folder where your 10 RAW files are. (Copy the file canon-raw-stack-average.bat to the folder full of RAW files.) Make sure that your folder of RAW files has only the RAW files in it that you want to stack, and nothing else (except the .bat file of course)!

    Once you have 10 RAW files and one .bat file in that folder, just double-click the .bat file to run it. You should get

    a little black box with some writing in it

    Otherwise known as “The Command Line”. πŸ™‚ If everything works out right, the script should run for several minutes, and then it should say, “Press any key to continue…” Pressing any key will exit the command line window. Then you should find a file called averaged.tif in your folder full of RAW files, and RawTherapee should open that file to be edited.

    If you get any errors, let me know what it says, and we’ll try to work through it.

    #18938

    Austin Vinar
    Participant

    Wow! Thanks a lot for the help! I am trying to run it now, and I will post the final results.

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