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Astrophotography and Sketching >> DSLR & Digital Camera Astro Imaging & Processing

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Footbag
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Loc: Scranton, PA
NGC1499 - The California Nebula - H-alpha
      #5611811 - 01/08/13 11:52 AM

My first H-alpha DSLR image. Managed to get 10m subs through my WO66. It was a warm 26F, and when I woke up this morning everything was covered in frost.

Processing this was tough. I wsn't quite sure how to do it. I ended up stacking in DSS in Superpixel mode which down scales the image. Then I took it into photoshop and copied out only the red channel. Then I processed it as greyscale. Seems easy, but greyscale reverses all of the curves tools, so I was struggling.

NGC1499 - The California Nebula
Scranton, PA - Redzone
28 X 10m lights, 15 darks, 25 flats, 25 bias
Canon XS, 12nm H-alpha filter, WO66 w/.8x reducer
Mach 1, Guided through Edge HD800


Larger Image

A new version with new processing and orientation.

New Version

Edited by Footbag (01/08/13 02:58 PM)


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terry59
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Re: NGC1499 - The California Nebula - H-alpha new [Re: Footbag]
      #5611916 - 01/08/13 01:08 PM

Convert it to RGB and delete the G and B channels. Much easier to work on.

Edit: I'm not much of a fan of DSLR Ha images but yours looks pretty good Adam.

Edited by terry59 (01/08/13 01:10 PM)


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srosenfraz
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Re: NGC1499 - The California Nebula - H-alpha new [Re: terry59]
      #5612256 - 01/08/13 04:22 PM

You have some excellent details with this image, Adam. You also did a great job pulling out some of the faint outer areas.

I know what you mean about working with the backwards greyscale curves. Its rather confusing when you're accustomed to editing RGB curves. One thing I've done when processing Ha is to copy the Red channel to the Green and Blue channels. This will give you an RGB grey image, but it'll also have the same luminance values as the original Red channel.


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Footbag
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Re: NGC1499 - The California Nebula - H-alpha new [Re: srosenfraz]
      #5612276 - 01/08/13 04:34 PM

Quote:

One thing I've done when processing Ha is to copy the Red channel to the Green and Blue channels. This will give you an RGB grey image, but it'll also have the same luminance values as the original Red channel.





Thanks. I hadn't considered doing that.

Edited by Footbag (01/08/13 04:34 PM)


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terry59
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Re: NGC1499 - The California Nebula - H-alpha new [Re: srosenfraz]
      #5613449 - 01/09/13 10:22 AM

Quote:

You have some excellent details with this image, Adam. You also did a great job pulling out some of the faint outer areas.

I know what you mean about working with the backwards greyscale curves. Its rather confusing when you're accustomed to editing RGB curves. One thing I've done when processing Ha is to copy the Red channel to the Green and Blue channels. This will give you an RGB grey image, but it'll also have the same luminance values as the original Red channel.




Interesting Scott. How different is the result from just deleting the B and G?


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Footbag
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Re: NGC1499 - The California Nebula - H-alpha new [Re: terry59]
      #5613775 - 01/09/13 01:55 PM

Quote:

Quote:

You have some excellent details with this image, Adam. You also did a great job pulling out some of the faint outer areas.

I know what you mean about working with the backwards greyscale curves. Its rather confusing when you're accustomed to editing RGB curves. One thing I've done when processing Ha is to copy the Red channel to the Green and Blue channels. This will give you an RGB grey image, but it'll also have the same luminance values as the original Red channel.




Interesting Scott. How different is the result from just deleting the B and G?




I wasn't able to delete the G & B. I was able to convert the Red channel to greyscale. Then change that greyscale to RGB. From what I noticed, the data didn't change; but the curves tool stayed the same so I didn't have to change my technique.

Otherwise in greyscale, curves is reversed.


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srosenfraz
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Re: NGC1499 - The California Nebula - H-alpha new [Re: terry59]
      #5614279 - 01/09/13 06:50 PM

Quote:

Quote:

You have some excellent details with this image, Adam. You also did a great job pulling out some of the faint outer areas.

I know what you mean about working with the backwards greyscale curves. Its rather confusing when you're accustomed to editing RGB curves. One thing I've done when processing Ha is to copy the Red channel to the Green and Blue channels. This will give you an RGB grey image, but it'll also have the same luminance values as the original Red channel.




Interesting Scott. How different is the result from just deleting the B and G?





Its pretty subtle. What I find is that copying red to the other channels seems to start it out with a higher contrast version than deleting the channels and extracting it. With additional curves, you could almost certainly end up with the same final results with either method.


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