Quick Tip: How to Remove Ugly Star Halo Color

Removing ugly halos from stars is quick and easy with Lightroom or Photoshop!

Now that you’ve learned how to photograph the Milky Way, you may have noticed some nasty coloration around your stars. Resulting from close-but-not-quite-in-focus stars or shooting with a wide open aperture on a lens that isn’t perfect — star halos, chromatic aberration, or blooming can ruin an otherwise beautiful night-sky image. While looking through some of the photos from a recent trip to the beautiful dark skies of Namibia, I realized that shooting for 9-nights straight caused me to take a few shortcuts that bit me in the end. Some of my photos had ugly purple and blue rings around the stars! Luckily, fixing this problem with Lightroom or Photoshop is easy, and I’ll tell you about it here.

This process is very easy, and I recommend you do it as one of the first steps in your processing workflow. Starting out with a properly calibrated image by removing lens imperfection issues is a good step to getting the most out of your astrophotography from the beginning.

So, zoom into those photos and check out your brighter stars. Do they look like this? Then you may have a problem! Luckily we can fix it. So, fire up your application of choice (Adobe Lightroom or Photoshop) and let’s do this.

Remove star halos in Lightroom

1. Import your images into your Lightroom Library.
2. Select the photo with the star halos that need to be removed.
3. Open the Develop tab, and zoom in to an area with offending stars on the image.
4. On the right side, where you make image modifications, scroll down until you see Lens Corrections.
5. Click Profile or Color, and make sure Remove Chromatic Aberration is selected.
6. Click Manual or Color, and look for the Defringe section.
   

For purple or blue star halos (most common):

1. Adjust the purple Amount slider to a little more than midway, this is just a starting point.
2. While watching the offending star, adjust the right and left sliders of the Purple Hue adjustment until the star halo starts to disappear to your liking.
3. Finally, back off the purple Amount slider until the star halos reappear, then push it up just until they disappear again to find the sweet spot.

For green or yellowish halos:

1. Adjust the green Amount slider to a little more than midway, as a starting point.
2. While watching the offending star, adjust the right and left sliders of the Green Hue adjustment to match the color until the star halos start to disappear to your liking.
3. Finally, back off the green Amount slider until the star halos reappear, then push it up just until they disappear again to find the sweet spot.

Remove star halos in Photoshop

Requirement: As with our awesome EasyNR noise reduction Photoshop action pack, removing color fringe from photos requires the Camera Raw utility in Photoshop, which is best utilized in Photoshop CC or later.

1. Open your photo in Photoshop, preferably the raw image (but JPG or other formats work as well).
2. If the Camera Raw filter does not open automatically (it won’t for a non-raw image), go to Filter->Camera Raw Filter and click to open.
   
3. Zoom in closely to an area with larger stars containing the offending star halos.
4. Open the Lens Corrections tab on the right side of the window, and look for Defringe.
   
5. Follow the Lightroom directions (above) to remove of purple/blue or green/yellow star halos.
6. Once you’re happy with the results, click OK.

Next steps

Now you can proceed with the rest of your normal photo editing workflow, while starting out with a much cleaner image to begin with. And when you think you’re finished, I’d be remiss if I didn’t highly recommend a few more tweaks to bring out the full beauty in your photos with our Milky Way Finisher Photoshop Action Pack Bundle.

As always, leave any questions in the comments section below!