Finally a Practical Use for Dust & Scratches Filter

Hot pixels are something that plague every night sky photographer. They are little red, blue, or green pixels that show up in the shadow areas of your photo when you increase the shadows slider in a dark area.  They can be easy to clone out, but where there is one, there is usually 100 more. Cloning would take a LOT of time, thank goodness for the Dust and Scratches filter!

Of all the things I have ever stumbled across in my Photoshop education endeavors, I never thought I would ever teach the dust and scratches filter.  But, this filter has an efficient use for fixing hot pixels in Milky Way photographs, or any night sky photo for that matter. It just needs to be coupled with the right blend mode, the color blend mode.

The Dust and Scratches Filter is a straightforward filter.  It looks assesses the pixels in your photo and can make other pixels around it look like it. As you set the radius to your desired amount, you will see almost a sort of blurring happening in your photo, but what Photoshop is doing is making all the pixels around each other take on the other’s characteristics. 

This is a much faster process than a blurring of pixels using something like smart blur or gaussian blur, and it is effortless to accomplish.  In today’s tutorial, I will show you how to make hot pixels magically disappear with the Dust and Scratches filter and the Color Blend mode.

Don’t have the time to watch it  I get it, here is the lowdown:

• Duplicate your background layer
• Apply the Dust and scratches filter (Found in Filter > Noise > Dust and Scratches)
• Set the Radius to anywhere between 3 and 5 (or just enough until you see the colored pixels disappear)
• Set your threshold to 1 and press ok
• Your image should look like a Monet at this point, that is okay
• Set the Dust and Scratches layer to the Color Blend mode and BAM! Hot pixels are fixed.
• You may want to put a mask on this layer, so it only affects your desired area