Dust Spot Removal – The Digital Photographer’s Nemesis

By Sean Bagshaw

Hart Mountain

The nemesis of today’s digital photographer is dust spots. Despite our best attempts at sensor cleaning and even with the introduction of sensor cleaning modes in our cameras we inevitably end up doing spot removal as part of our image processing workflow.

In fact, as part of the non destructive digital processing workflow that I teach, spot removal is the first thing I tackle once the image has been opened in Photoshop. The best time to remove spots is at the bottom of the layer stack either on the background image or on a cloning layer directly above the background image. Cleaning up the image before moving on to other developing procedures is really important. Depending on what type of developing techniques you use on an image it can be anywhere from difficult to near impossible to remove dust spots without leaving artifacts at later stages in the process.

However, even when I do a careful job of spot clean-up I frequently miss some. Often there are spots that are so faint they are nearly invisible in the undeveloped image but show up several steps down the line after adjustments to contrast, luminosity and clarity have been made. At best, I notice them and can remove them without too much time and trouble. Worse is when I have to back track several steps in my processing to remove them and start over from that point. The worst is when I fail to notice them at all until I have already enlarged and printed the image and find them jumping off the page at me.

Fortunately there is a simple way to preemptively combat this annoyance through the use of what my friend Mac Holbert calls a “revealing layer”. Taking the extra few seconds to use a revealing layer has saved me much time and many headaches in the long run. Here is how it works:

Raw Image

Raw Image

obvious dust spots

A couple obvious dust spots are visible.

  • With the unprocessed image opened in Photoshop add any type of adjustment layer that can be used to increase contrast. I like to use a Curves adjustment layer and use an “S” curve to boost contrast. You can also use a Contrast/Brightness adjustment layer, a Levels adjustment layer or even a Curves adjustment layer with the blending mode set to Overlay. Whatever you do the point is to crank the contrast way up.
Curves Layer and S Curve

Curves reveal layer and "S" curve contrast adjustment.

  • The enhanced contrast should make all your dust spots jump off of the screen at you, even the ones that were previously so faint as to be undetectable. Now select the background layer and view the image at 100% magnification. Scroll through and remove dust spots with the technique of your choice. In CS5 the Spot Healing Tool set to Content Aware usually does the best job.
hidden spots revealed

Many hidden spots are revealed and can now be removed.

  • Once you have removed every last spot simply delete the high contrast “reveal layer”. Now you can continue with your workflow confident that you have removed even the wiliest of those suckers and none will be showing up to surprise you after three hours of work.
Final Image

The final mastered image still free of dust spots even after significant contrast, luminosity and clarity adjustments have been made.

  • If you prefer to do your spot removal in Lightroom you can use the same basic concept. Use a combination of the Contrast slider and Clarity slider to boost contrast and make even the faintest spots show up. Remove them with the Spot Removal tool and then set the Contrast and Clarity sliders back to where you want them.

If you have any questions for me or your own spot removal tip you’d like to share please leave me a note in the comments section.  I’d love to hear from you.  Cheers!

The nemesis of today’s digital photographer is dust spots. Despite our best attempts at sensor cleaning and even with the introduction of sensor cleaning modes in our cameras we inevitably end up doing spot removal as part of our image processing workflow.

 

In fact, as part of the non destructive digital processing workflow that I teach, spot removal is the first thing I tackle once the image has been opened in Photoshop. The best time to remove spots is at the bottom of the layer stack either on the background image or on a cloning layer directly above the background image. Cleaning up the image before moving on to other developing procedures is really important. Depending on what type of developing techniques you use on an image it can be anywhere from difficult to near impossible to remove dust spots without leaving artifacts at later stages in the process.

 

However, even when I do a careful job of spot clean-up I frequently miss some. Often there are spots that are so faint they are nearly invisible in the undeveloped image but show up several steps down the line after adjustments to contrast, luminosity and clarity have been made. At best, I notice them and can remove them without too much time and trouble. Worse is when I have to back track several steps in my processing to remove them and start over from that point. The worst is when I fail to notice them at all until I have already enlarged and printed the image and find them jumping off the page at me.

 

Fortunately there is a simple way to preemptively combat this annoyance through the use of what my friend Mac Holbert calls a “revealing layer”. Taking the extra few seconds to use a revealing layer has saved me much time and many headaches in the long run. Here is how it works:

 

  • With the unprocessed image opened in Photoshop add any type of adjustment layer that can be used to increase contrast. I like to use a Curves adjustment layer and use an “S” curve to boost contrast. You can also use a Contrast/Brightness adjustment layer, a Levels adjustment layer or even a Curves adjustment layer with the blending mode set to Overlay. Whatever you do the point is to crank the contrast way up.

  • The enhanced contrast should make all your dust spots jump off of the screen at you, even the ones that were previously so faint as to be undetectable. Now select the background layer and view the image at 100% magnification. Scroll through and remove dust spots with the technique of your choice. In CS5 the Spot Healing Tool set to Content Aware usually does the best job.

  • Once you have removed every last spot simply delete the high contrast “reveal layer”. Now you can continue with your workflow confident that you have removed even the wiliest of those suckers and none will be showing up to surprise you after three hours of work.

  • If you prefer to do your spot removal in Lightroom you can use the same basic concept. Use a combination of the Contrast slider and Clarity slider to boost contrast and make even the faintest spots show up. Remove them with the Spot Removal tool and then set the Contrast and Clarity sliders back to where you want them.

 

 

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~ by Sean Bagshaw on April 2, 2011.

7 Responses to “Dust Spot Removal – The Digital Photographer’s Nemesis”

  1. thank you..thank you … thank you

  2. Oh, thanks! What an easy way to avoid the prob. I always look at every inch of the photo before I print but sometimes I still miss something and that’s such a pain. This should really help.

  3. Adding a high contrast layer to “pop-out” the dust spots is a great idea (and as you indicated saves a lot of time later after you discover you missed a bunch of spots that only show up after additional processing)! For a truly non-destructive workflow I always add a new layer just above the background layer (after renaming and therefore unlocking the background layer). It is on this new layer that I do dust removal using the Spot Healing tool.

    • Michael – Thanks for your ideas on this. I agree that keeping the workflow non-destructive is the best practice and your method works well. However, for simple dust spot removal I’m OK with doing it on the background layer since it is usually simple and I know I’m never going to want those dust spots back. It also keeps the file size smaller. When I do major cloning I avoid doing that on the background layer so it is non-destructive. However, I do this on an empty layer above the background layer with the clone/healing tool set to sample current and below. This keeps the file smaller than creating a copy of the background.

  4. Great tip, thank you very much. (Gorgeous image too.)

  5. Thanks for the tip–should be useful. (I have to admit: seeing all those red circles made me feel better about the numerous spots I often discover…yes, even after printing…on my images!)

  6. Thank You for the great tip, amazing how many show up, will try that on my next image for sure!

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