Over the last few posts we’ve looked at several of the Blur Gallery settings including Tilt Shift, Path Blur, Iris Blur and Field Blur. In all these cases there’s been a check box we haven’t used, so lets take a look at that here.
Save Mask to Channels
In this post I’ll be using this image:
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, it’s 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.
Here we can see how Photoshop is processing our blur. Where the mask is black there is no blur, whilst 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 it 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.
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 to solely control the mask of Levels and Saturation!
As always, a big thanks to Eric for supplying this super detailed tutorial. Stay tuned for next week and in the meantime, check out more of his tutorials on his website, YouTube and you can find him on Facebook and Twitter should you wish to get in touch with him!