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Photoshop Blur – Save Mask to Channels

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In this post I’ll be using ‘Just married couple in poplar background’ File: #68344933 by javiindy

If you’ve used the Blur Gallery’s Tilt Shift, Path Blur, Iris Blur and Field Blur you may have noticed a check box called ‘Save Mask to Channels’, in this post I’ll take a look at just some of the possibilities this opens up;


I’ve been busy adding pins to this image using Field Blur as a Smart Filter. At the top of the screen there’s a couple of check boxes, one of which is the Save Mask to Channels. I’ll check that here before I click ‘OK’



Although Channels is where you’ll find the luminance data for colour channels its also where Photoshop keeps masks and Alpha channels. By selecting to save the mask in the blur dialogue Photoshop created a new channel that can be quite detailed and complicated.


(The other channel you can see here ‘Layer 0 Filter Mask’ (A) is that of the mask for the Smart Filters (B). At this time each filter can’t be masked out individually)

You can view the mask by pressing Alt (PC) or Option (Mac) and clicking the thumbnail of the channel.


The Mask

Here we can see how Photoshop is processing our blur. Where the mask is black there is no blur while the lighter the mask is the more blur is added.

Here I’ve made a copy of the mask and laid it on top of the image so we can see whats happening;


Using the Mask

There’s many ways we can use the mask once we have it, one of the most helpful is to use is in conjunction with the Adjustment Layers. In this we can adjust the image in accordance to how much blur there is.

To select the mask, head back to the Channels panel and hold down Ctrl (PC) or Cmd (Mac) and click the thumbnail. (You should get a pointed finger and dotted square cursor)


This selection may not look like its done much, nor will it look as complicated as your mask possibly is.


Photoshop is showing the selection of the lightest part of the mask, but its all selected.

Adjustment Layers

Now we have the mask selected we can go and select an Adjustment Layer, in this case I’ll select  Levels.


With the Levels Adjustment Layer selected Photoshop has applied the mask from the outset, so any adjustment I make will be influenced by it. In this case I’ll raise the mid point slider a little to darken the image;


This matches the blur exactly of course. I’ll do the same with Hue/ Saturation;


Now the blur amount, luminance and saturation match.

You Don’t Have To Blur

Adding a blur is great, but as you can see above this is a great way to build masks. In the finished image here I’ll turn off the Field Blur and use it solely to control the mask of Levels and Saturation!




This tutorial was first published on the Fotolia Blog 1.9.15

About Eric Renno (435 Articles)
Eric’s background in video editing with Adobe Premier led to his interest, and then obsession, with Photoshop. Starting TipSquirrel.com as a hobby he is proud to have gathered together and be a part of The Photoshop Nuts. Known as only “TipSquirrel” for two years, Eric ‘went public’ when he was a finalist in The Next Adobe Photoshop Evangelist competition. He’s also been a finalist in Deke’s Techniques Photoshop Challenge. While still taking on some freelance work, Eric has recently become a Lecturer at Peterborough’s Media and Journalism Centre where he enjoys sharing his knowledge as well as learning new skills. This realisation that he loves to teach has made Eric look at altering his career path.

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